What is the best keto supplement?

Keto powders often come with flavoring while at the same time being sugar-free and low net carb. You can find basic flavors like vanilla or chocolate, but some manufacturers offer more inventive flavors. If you have a sweet tooth, select a powder sweetened with stevia, a natural nonsugar substitute, over artificial sweeteners to keep with your macros.
Keto supplement prices
Keto supplements can be as little as $11 for a bottle of MCT oil softgels to $70 for a container of multi-ingredient keto powder.
Q. Why are electrolytes an important supplement for a keto diet?
A. Especially when you start a keto diet, your kidneys will dump excess water, which puts you at risk for losing key minerals, like potassium, calcium, sodium, and magnesium. This can result in “keto flu” symptoms like fatigue, brain fog, and other unpleasant symptoms that can be mitigated by an intake of these key electrolytes.
Q. Is caffeine allowed on a keto diet?
A. Yes, in fact many keto supplements contain caffeine, usually in the form of green tea, to combat fatigue associated with starting a keto diet. They are also included in keto supplements formulated for workouts and athletes, as caffeine is a performance enhancer.
Keto supplements we recommend
Best of the best: Zenwise Health Keto-Lift BHB Powder
Our take: A best-selling keto powder that’ll boost your workouts sans caffeine.
What we like: Jitterless formula that’ll boost workouts, cognitive function, and metabolism. No carbs. Mixes well into any beverage.
What we dislike: Not everyone likes the raspberry lemonade flavor.
Best bang for your buck: Life Extension 7-Keto DHEA Metabolite Capsules
Our take: Affordable DHEA supplement for keto followers.
What we like: Doctor-recommended supplement, especially for males over 50. Boosts mental clarity and testosterone in men.
What we dislike: Hormonal-related side effects.
Choice 3: Code Age Keto Electrolyte Capsules
Our take: Essential electrolytes in easy-to-swallow capsules.
What we like: Good price point. Sugar-free pills contain magnesium, potassium, and calcium. Can be taken pre-workout for an energy boost.
What we dislike: Not high enough in sodium for some keto users.
Ana Sanchez is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money. BestReviews never accepts free products from manufacturers and purchases every product it reviews with its own funds.
BestReviews spends thousands of hours researching, analyzing and testing products to recommend the best picks for most consumers. BestReviews and its newspaper partners may earn a commission if you purchase a product through one of our links.
Distributed by Tribune Content Agency, LLC.


Prüvit Keto OS Products: Should You Try Them?

While the ketogenic diet has been extensively researched and its benefits substantiated, research on exogenous ketones is in its early stages.

However, there are several studies on the potential benefits of exogenous ketones that have had promising results.

May Improve Athletic Performance

Due to the body’s increased need for glucose (blood sugar) during intense training, the glucose-sparing qualities of exogenous ketones may be helpful for athletes.

Low levels of muscle glycogen (the storage form of glucose) have been shown to inhibit athletic performance (6).

In fact, “hitting the wall” is a common term used to describe the fatigue and energy loss related to the depletion of muscle and liver glycogen reserves (7).

Some studies have demonstrated that providing athletes with exogenous ketone supplements may improve athletic performance.

One study of 39 high-performance athletes found that drinking 260 mg of ketone esters per pound of body weight (573 mg/kg) during exercise improved athletic performance.

The athletes in the study who consumed the ketone drink traveled an average of 1/4 mile (400 meters) farther over a half hour than those who consumed a drink containing carbohydrates or fat (8).

Exogenous ketones may also help you recover more quickly after intense workouts by promoting the replenishment of muscle glycogen.

However, exogenous ketones may not be effective for athletes who participate in exercises that require short bursts of energy like sprinting. This is because these exercises are anaerobic (without oxygen) in nature. The body needs oxygen to break down ketones (9).

Additionally, the exogenous ketone supplements currently available on the market contain ketone salts, which are less potent than the ketone esters used in current studies.

Could Reduce Appetite

The ability of the ketogenic diet to reduce appetite and help with weight loss has been demonstrated in many studies (10).

The elevation of ketones in the blood associated with the ketogenic diet has been linked to a reduction in appetite (11, 12, 13).

Supplementing with exogenous ketones may be an effective way to reduce appetite, as well.

Ketones can suppress appetite by impacting the hypothalamus, a part of the brain that regulates food intake and energy balance (12).

One study of 15 people found that those who consumed 0.86 calories of ketone esters per pound (1.9 calories/kg) of body weight had significantly less hunger and desire to eat, compared to those who consumed a carbohydrate drink.

What’s more, hormones that increase appetite like ghrelin and insulin were significantly lower in the group that consumed the ketone ester drink (14).

May Help Prevent Mental Decline

Ketones have been shown to be an effective alternative fuel source for the brain in times of low glucose availability.

There is also evidence that ketone bodies help reduce neurological damage by blocking inflammasomes, a group of protein complexes that cause inflammation in the body (15).

Supplementing with exogenous ketones has helped improve mental function in many studies, particularly in people with Alzheimer’s disease (16).

Brain glucose uptake is impaired in people with Alzheimer’s disease or mild cognitive impairment. Thus, it has been suggested that the gradual depletion of brain glucose can contribute to the progression of Alzheimer’s disease (17).

One study followed 20 adults with Alzheimer’s disease or mild cognitive impairment.

Increasing their blood levels of beta-hydroxybutyrate by supplementing with MCT oil — a type of saturated fat that promotes ketone production — led to a greater improvement in cognitive performance, compared to a placebo (18).

Several studies on rats and mice with Alzheimer’s disease have found that supplementing with ketone esters led to improvements in memory and learning, plus helped reduce anxiety-related behavior (19, 20, 21).

Exogenous ketones have also been found to help reduce neurological damage related to epilepsy and Parkinson’s disease (22, 23, 24).

May Help You Reach Ketosis More Quickly

Reaching a state of ketosis has been associated with weight loss, better appetite control and protection from chronic diseases like diabetes (10, 25).

However, achieving ketosis by following a ketogenic diet or fasting can be difficult for many people. Exogenous ketone supplements can help you get there more quickly.

Prüvit Keto OS supplements contain both beta-hydroxybutyrate and MCT powder.

Supplementing with both beta-hydroxybutyrate and MCTs has been shown to effectively raise levels of ketones in the blood without the need for dietary change (22).

However, it’s important to note that ketone salts, which are the kind of ketones found in Keto OS, are much less effective at raising ketone levels than ketone esters.

In several studies, supplementing with ketone salts resulted in beta-hydroxybutyrate levels of less than 1 mmol/L, while taking ketone esters raised blood beta-hydroxybutyrate concentrations to 3 to 5 mmol/L (26, 27, 28).

Even though the benefit may be small, exogenous ketone salt supplements like Keto OS do provide a quick boost of ketones.

Recommendations for blood ketone levels vary depending on your goal, but most experts recommend a range between 0.5–3.0 mmol/L.

Those beginning a ketogenic diet sometimes find exogenous ketones to be helpful not only in raising ketone levels but also in reducing symptoms of “keto flu.” These include nausea and fatigue, which sometimes occur in the first weeks of the diet as the body adjusts.

Summary Exogenous ketone supplements may help boost athletic performance, reduce appetite and prevent mental decline. They may also be beneficial for people trying to reach ketosis more quickly.

Should You Use Exogenous Supplements to Put Your Body in Ketosis?

Keto — the diet du jour that celebs like Mick Jagger and Halle Barry are said to have tried — is an entirely new way of eating. Instead of carbohydrates making up the majority of your calories, fat takes the No. 1 spot and carbs are extremely limited when following the ketogenic diet.

“What happens when you deprive your body of carbohydrates is your body uses the fat as energy,” says Abby Langer, RD, Toronto-based founder of Abby Langer Nutrition. Eating this much fat produces ketone bodies and leads to ketosis, which means the body looks to fat rather than carbohydrates for fuel.

What’s the benefit? For a lot of people, it’s all about weight loss. “Generally, ends up being low-calorie,” Langer says. “You’re eating 80 percent of your calories in fat, but it’s very filling.”

RELATED: Everything You Need to Know About the Ketogenic Diet

Dina Griffin, RDN, with eNRG Performance in Littleton, Colorado, says people are also drawn to the diet for the potential anticancer and anti-inflammatory benefits and the positive effect it’s been shown to have on athletic performance.

But the problem is, it’s hard to maintain ketosis, and one snack is all it takes to slip up. “Anytime you go over 50 grams (g) of carbohydrates, you’re going to kick yourself out of ketosis and the weight is going to come back,” Langer says.

That’s where exogenous ketones come in.

What Are Exogenous Ketones Exactly?

The idea is when you eat something that’s not keto-friendly, you can reach for exogenous ketones to keep your body in ketosis. The word exogenous means created externally, and these supplements are forms of the ketone beta-hydroxybutyrate (BHB), which your body normally creates on its own.

“The purpose is to, in a timely fashion regardless of your dietary pattern, raise your blood level of ketone bodies,” Griffin says. Of course, your body can get back into ketosis through your diet, but that can take a few days, so exogenous ketones are designed to speed up the process.

Usually, you’ll find exogenous ketones in the form of powdered ketone salts. Less common are ketone esters, which are the purest form of ketones. Griffin says they work quickly (in 10 to 15 minutes, as opposed to an hour for the salts) and effectively, but they’re more expensive, have a more-revolting taste, and are harder to find (HVMN is one U.S. company that sells them). People also use medium-chain triglyceride (MCT) oil — or partially manmade fats — to put the body into a state of ketosis.

RELATED: What to Expect If You Try the Ketogenic Diet

Do Exogenous Ketones Work to Bring Your Body Back Into Ketosis?

Griffin says it depends on your expectations. You can’t just take them, eat a carb-heavy diet, and expect magic to happen. “The problem is a lot of people associate with, ‘That means I’m going to burn fat,’ and those don’t actually go together,” she says. “The ketones themselves don’t make you burn fat per se.”

Instead, they should be viewed as supplements to the keto diet. “They can enhance that state that you achieve through your dietary choices,” Griffin says. But, yes, you still have to put in the work.

Though research involving ketone supplements is still in the early stages, it seems promising. One study published in February 2018 in Obesity suggests exogenous ketone esters lower hunger hormones and act as appetite suppressors. That can lead to weight loss because “if we don’t feel hungry, gosh, we probably aren’t going to eat like we were,” Griffin says.

RELATED: 8 Steps Beginners Should Take Before Trying the Keto Diet

Another study published in February 2018 in the Journal of Physiology found drinking a ketone ester supplement may lower blood sugar. The study was done on healthy individuals but could be helpful if similar results were found among people with type 2 diabetes.

The Potential Downsides of Using Exogenous Ketones

A serving of exogenous ketones will set you back only 100 calories or less, but most people who’ve tried them — including Langer — say they taste awful. And they’re expensive. A two-week supply could run you $50 or more. Both Griffin and Langer say that money could be better spent on whole foods.

Griffin says that because ketone salts are usually made up of ketones bound to sodium, they can be dangerous for people with high blood pressure. “There could be an issue there with heart health and heart function — that would be one concern I would have,” she says.

She also cautions that the supplements may cause stomach distress. “Some of these can really tear up our guts,” she says, adding that downing an entire serving may send you running for the bathroom. To reduce that risk, she suggests starting small — maybe one-third of a serving or one-half of a serving until your body adjusts.

RELATED: 7 Supplement Risks Every Woman Should Know

How to Pick a Good Exogenous Ketone Supplement

Because they’re so expensive, you want to make sure you pick a good one. Griffin and Langer say to ignore the companies that make these supplements sound too good to be true. Just like with any supplement, Griffin says it’s important to look at what’s in it. Beware of products with lots of fillers and instead go for one with a short, straightforward list of ingredients (Griffin likes the options from KetoSports).

The Bottom Line on Using Exogenous Ketones for Ketosis

There’s some support that exogenous ketones can be helpful for people already dutifully following the keto diet — but research has been limited. One thing we know for sure: These aren’t a get-thin-quick solution. “I think people are drawn to a quick, easy fix, kind of a magic bullet supplement, and it’s not that this won’t contribute to weight loss, but it’s not that magic bullet,” Griffin says.

Langer sums it up this way: “You have to put the effort in,” she says. “If you want to be in ketosis, do the ketogenic diet. You cannot just relax and eat whatever you want and automatically lose weight with this or any other product.”

Keto Drinks: Your Guide to Keto-Friendly Beverages

If you’re considering the keto diet, you may think it’s extremely difficult maintain. The low-carb, high-fat diet will certainly require a lifestyle change, but it may also illuminate hidden sources of carbs in your everyday diet—especially in regards to sugar intake. People tend to underestimate this one. This is no truer than with beverages, as folks usually overlook how much sugar is in some of their favorite drinks.

Many everyday beverages may contain more calories and carbs than you would believe possible. To make matters worse, the majority of these carbs will come strictly from refined, processed sugar.

The glass of orange juice you had with breakfast? That’ll be 120 calories and 10 grams of carbs. The morning trip to your local coffee shop? That drink could have as many as 600 calories and 75 grams of carbs. The soda at lunch? It’s worth 200 calories and 40 grams of carbs.

These hidden calories from sugar may be compromising your health and weight loss objectives. Drinks such as juices, sodas, and flavored coffees come jam packed with large amounts of processed sugar, which spell disaster for a ketogenic diet. By following our guide below, you will be closer to staying keto-friendly, and learn how to dodge the constant sneak-attacks from sugar lurking in our everyday diet.

The perfect keto diet menu

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Zero-Carb and Low-Carb Beverages

There are several keto-friendly, low-carb drinks out there. It’s important to be informed about what you’re drinking, because even a small amount of sugar can kick you out of ketosis.


This is the most abundant fluid on Earth, and the most precious liquid for life in general. Though not necessarily the most sexy or popular option, every person on a keto diet should start here. Water makes up 75% of our body weight and can affect health, energy, performance, and overall function.1

Humans can lose around 1% – 2% of total body water during a typical day just as a result of simple routine activities. Many adults tend to drink less than half the recommended daily value of water, and as a result, may experience unpleasant consequences of dehydration.2 Men should drink about four liters of water per day, and women should drink about three liters per day, and in both cases, requirements are likely more if you’re active. Ensuing you hit your daily water minimum is important. Dehydration has shown to be detrimental to both physical performance and cognition.

Not only is water the basis for survival, but it also is the most versatile option of all the beverages on the keto-drink list.

Plain water may be commonly thought of as a boring, flavorless liquid, but it can be jazzed up numerous ways.

  • Adding squeeze of citrus juice: Take a wedge of lemon or lime and squeeze a small amount into your drink. You could even add cucumber or mint and refrigerate for freshness. This can add a lot of flavor with little-to-no calories involved
  • Carbonated / sparkling water: Simply adding some bubbles to your water by using a carbonation machine can give your water an effervescent quality. If you choose not to produce your own carbonated water, there are several options available commercially
  • Zero-calorie flavoring: Water enhancers that are zero calorie can add a lot of flavor with just a small squeeze. There are several out there you can purchase, varying in flavors. Be sure to moderate your intake of artificial sweeteners and consume in moderation

Consuming enough water daily is not only vital to overall health, but it may help prevent problems such as constipation, urinary tract infections, and kidney failure. Did we forget to mention it’s keto friendly? Do we need to?


Coffee is one beverage that has been consumed for centuries with its origins dating back well over one thousand years. Coffee consumption has been controversial at times—it was once seen as a drink linked to heart disease and high blood pressure. However, views on coffee have substantially changed over the years, and now the drink has become a beverage staple crossing cultural lines and international borders for generations.

Coffee has gone from simple bean to multi-billion dollar industry. But in its purest form, coffee is an all-natural crop that is farmed, harvested, roasted and filtered over water. Coffee was once viewed as detrimental to health but has now been shown to have positive health benefits in modest amounts.3

Some of the health benefits associated with modest coffee consumption include:

  • Improved weight maintenance through thermogenesis and fat oxidation4
  • Appetite suppression4
  • Lower risk of some cancers5
  • Increased energy

One problem with the line up at your local coffee shop: it’s so easy to add large amounts of sugar to coffee in the form of flavored syrups.

This increases its carb count making it an enemy of the keto diet. Think about all the sugar in a frappuccino! Lattes should also be avoided as milk contains a high amount of carbs as well.

You may be thinking, “There is absolutely no way I am drinking black coffee.” Fair enough. Black coffee is an acquired taste for most people. Good news is, there are keto-friendly options to make your coffee less bitter and more palatable.

  • Add heavy cream: Heavy cream is low in carbohydrates and high fat, helping to minimize the bite associated with black coffee
  • Make MCT coffee: Many people have begun adding medium-chain triglycerides (MCTs) to their coffee. MCTs aren’t exactly ketones, but they’re fatty acids readily converted into ketones. The main source of MCTs is coconut oil. If you’re looking for a zero net-carb option, we suggest opting for powders made from pure C8 Caprylic Acid (the world’s most ketogenic fat).
  • Add nut milk: Adding nut milks such as almond milk or cashew milk are low carb options that add very few calories to coffee drinks

These options can make black coffee a bit more palatable without all the unnecessary sugar you may get from a local coffee shop. But if coffee isn’t your cup of tea? Well maybe try…tea.


The history of tea spans centuries and cultures all over the world. As one of the longest-standing beverages consumed by humans, tea has been a practical drink that is both medicating and beneficial.

Tea is the second most widely-consumed beverage on the planet (behind, of course, water). Recent studies have suggested that tea may help reduce the risk of developing chronic diseases such as cancer, cardiovascular disease, arthritis, and diabetes.6

In addition to the physiological benefits, certain varieties have other positive benefits including:7

  • Reduction of anxiety
  • Improved cognition
  • Improved memory

An amino acid in tea, called L-theanine, might be responsible for some of these benefits. It has shown to increase focus and decrease stress—a powerful combo.8

Not only is tea beneficial to health, but many varieties, including herbal tea and green tea, are keto-friendly and part of a low-carb diet. The problem that exists with coffee runs parallel to tea: large amounts of sugar are often added to it.

Obviously, sweetened teas that contain a high sugar content are not part of a keto-friendly diet. Therefore, in order to stay in ketosis, you must limit your sugar intake by consuming unsweetened teas.

Low-Calorie or No-Calorie Sport Drinks

Our bodies need electrolytes. Electrolytes are electrically-charged elements that function to stimulate the body’s muscles and nerves. Electrolytes include sodium, calcium, potassium, magnesium and phosphate; they control the level of fluids in the body, affecting cellular function, blood volume level and blood pressure.

It is important to balance electrolyte levels in the body to ensure that the body can function optimally.

An electrolyte imbalance can result in dehydration and symptoms such as fatigue, vomiting, sweating, nausea, diarrhea, muscle cramps, lack of coordination, lack of focus, dizziness, increased body temperature, and kidney issues.

Sweat during exercise causes a loss of electrolytes and risk of dehydration. Therefore, athletes must consume electrolytes, and these are often a key component of sports drinks. Sports drinks aim for the correct balance of electrolytes, vitamins, minerals. During prolonged exercise, water alone fails to restore lost electrolytes, therefore, specially designed sports electrolyte drinks are most effective in maintaining optimal bodily fluids.

Unfortunately many popular sport drinks filling the locker room cooler are high in sugar and carbs. For the athlete practicing the ketogenic diet, this could spell disaster. The good news is that in today’s day and age, there are plenty of zero-calorie options that can provide the electrolytes needed to perform with low carb intake.

These options often come in effervescent tablet form, or as powders and are lightly-flavored, without all the added sugar.

Milk Substitutes

Traditional cow’s milk has been a staple in the human diet for centuries. In fact, humans have been consuming cow’s milk for almost 10,000 years.

Dairy milk contains a relatively high number of carbohydrates. Some people have issues digesting cow’s milk due to lactose intolerance. As much as 65% – 70% of the world’s population has some level of lactose intolerance.9

Due to the issues with digestion, several milk substitute products have been developed in recent years. The most popular varieties include almond milk, cashew milk, soy milk, and coconut milk. These substitutes are keto-friendly due to their low carb content.

What’s so great about milk substitutes? They can still be used in the same manner as traditional milk. Whether you choose to add it to cereal or coffee, the possibilities are endless.

Be sure to use an unsweetened variety of these nut milks as their sweetened counterparts contain high concentrations of sugar.

Keto-Friendly Alcohol

This one stirs up some controversy in keto circles. Certain types of alcohol can be apart of a low-carb diet in moderation, but there are certain alcoholic beverages that may completely derail your ketosis.

If you do choose to drink alcohol follow some of our tips below.

  • Drink spirits: Spirits such as scotch, whiskey, tequila, rum, or vodka contain carbs but the amount is less compared to other alcoholic beverages
  • Avoid sugary mixers: Alcohol can quickly add up in carbs and calories partially due to the fact that people mix these drinks with sugary sodas, juices, or drink mixes. If you do add a mixer, choose a low carb option (like soda water or citrus)
  • Avoid beer: Beer is jam-packed with carbs making it very unfriendly to the ketogenic diet

Keto or not, it’s important to note that alcohol should always be consumed in moderation. Drinking moderately on occasion likely will not alter your state of ketosis but try not to go overboard. And be sure to drink responsibly!

Exogenous Ketones

Ketosis happens two ways—endogenously (meaning, ketones are produced in the body, likely a result of diet or fasting) or exogenously (ketones consumed from an external source, likely a supplement drink). Endogenous ketosis can take days or weeks, so many people we employ an exogenous ketone supplement to help achieve ketosis faster.

MCTs (discuss previously) are not technically an exogenous ketone but they do bump up BHB levels somewhat (remember, they don’t actually contain ketones). Ketone salts are another option, these usually come as a powder to be mixed in water. But you should watch out, as regular use of ketone salts will cause you to consume far over the recommended daily allowance of sodium. Ketone esters provide a great option for almost-immediate, deep ketosis with increased levels of beta hydroxybutyrate (BHB).

Studies in elite cyclists have shown that exogenous ketone supplementation can improve performance by 2% – 3%, allowing for further cycling of 400m further in a 30-min time trial.10

Of course, these are keto-friendly drink options as they are free of sugar—but they can also increase ketone levels and kickstart ketosis.

Keto Smoothies

When the term “smoothie” comes up, you may instantly think of a high-sugar drink that isn’t keto-friendly.

While most smoothies contain high-fructose fruit or sugar, keto smoothies provide valuable nutrients such as fiber, while helping you stay in a state of ketosis.

There are several keto-friendly smoothies available made with low-carb fruit options to provide valuable nutrients. Try blending together 200ml unsweetened almond milk, 1 tsp stevia, 1 tbsp turmeric, 1 tsp cinnamon, 1 tsp ground ginger, 1 scoop MCT Oil, and 1 tbsp of Chia seeds to make a delicious breakfast smoothie.

Artificial Sweeteners

One topic to address when dealing with low- to no-calorie beverages is artificial sweeteners.

Many sugar-free products contain artificial sweeteners instead of sugar. There has been controversy in recent years over whether or not these artificial sweeteners are safe and/or healthy regardless of carb content.

Although artificial sweeteners are designed to replace sugar in low-carb beverages, observational data has shown that these sweeteners may be associated with increased body mass index (BMI) and obesity.11 Limiting the consumption of any type of sweetener may be the best option for preventing weight gain. Instead, identify natural sweeteners that have been shown to have positive effects on body weight and metabolism such as Stevia.12

Drinks to Avoid

The vast majority of consumer produced beverages contain high amounts of sugar. To avoid unwanted sugar and maintain ketosis, be sure to check the nutrition label on some of your favorite drinks Here are a few easy ones to keep an eye out for.


All types of soda should be avoided on a ketogenic diet whether it be regular, diet, or zero-calorie. Studies show a positive correlation between soda intake and a higher BMI.

Furthermore, these drinks have been associated with an increased risk of type 2 diabetes. While genetics obviously play in a role in the development of these diseases, there is no doubt lifestyle choices are also important.

Diet and zero calorie sodas are high in artificial sweeteners such as aspartame and sucralose. Diet soda has been said to produce an insulin response similar to regular sodas, thereby having some of the same deleterious side effects.13 People following a ketogenic diet should strive to eliminate these drinks from their diets.

Fruit Juice

In past generations, juice was thought of as a healthy drink providing valuable micronutrients such as Vitamin C and Calcium to children and adults alike.

In recent years, we’ve come to realize that traditional juice beverages are actually filled with sugar.

Fruit juice drinks such as apple and orange juice are naturally rich in sugar, making them extremely detrimental to a standard keto diet.14 Some manufacturers even add extra sugar to make them more palatable. Due to their high sugar content, juice drinks should not be consumed on a typical ketogenic diet.

Beer and Wine

Generally, alcohol isn’t a keto-friendly beverage. But as we discussed, there are certain alcoholic drinks that are more preferable to a keto diet—still, there are definitely some that should be avoided.

Beer is high in carbs and provides no nutritional value to dietary standards. All types of wine, including red wine and white wine, also contain high sugar as well. However, there are certain manufacturers that produce keto friendly wine. A drink or two is fine with careful selection and appropriate moderation.

Energy Drinks

Energy drinks have never been thought of as a healthy option since their introduction to the marketplace in the 1990s. In addition to the “caffeine crash” that many people experience while consuming these drinks, they also tend to contain harmful ingredients such as guarana and taurine.15

While there are zero-calorie options available, the large amounts of caffeine and other ingredients may be linked to incidences of heart rhythm disturbances and increased blood pressure.16

What Should You Drink?

Sugary drinks are ingrained in society; people will often have a sugary coffee drink in the morning, a soda with lunch, or a beer with dinner. All of these options are difficult to consume while on the keto diet because of their carbohydrate content. Especially as you start off on the keto diet, you should pay special attention to the nutrition facts for your beverages, as so many people guzzle carb-heavy drinks perfectly innocently, without even realizing they’re full of sugar.

Good news, though: in today’s modern day and age, there are plenty of keto options available, with more brands and flavors coming out all the time.

What is your best bet ? Stick to water and black coffee. If you need to spice things up a bit, try carbonated water with a fresh squeeze of citrus. It’s worth being diligent. You’ll feel so much more energized when you can train your body to run on ketones all day, rather than reaching for a mid afternoon sugary drink-pick-me-up.

How to easily increase ketone levels

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What to know about exogenous ketones

Researchers have carried out several studies on the potential benefits of taking EKs.

EKs for ketosis

A 2017 study investigated the effects of EKs on human metabolism. Researchers asked 15 healthy participants to consume drinks that contained either ketone esters or ketone salts. Both types of EK induced a state of ketosis in the participants.

However, this study involved only a small number of people. Further research is necessary to establish the accuracy of the findings.

EKs for enhanced athletic performance

Share on PinterestTaking EKs before exercise may enhance athletic performance.

Another potential use for exogenous ketones is in athletic performance. Prolonged physical activity can result in a lack of oxygen supply to the muscles, which leads to an increase in the production of lactic acid. Excess lactic acid can make muscles feel sore and weak.

As the authors of a 2016 study note, exogenous ketones act as an alternative energy source for the body during intensive exercise. As such, they help reduce lactic acid production.

The study results suggested that exogenous ketones could improve a person’s athletic performance by about 2%. The people most likely to benefit from this increase are elite and endurance athletes.

EKs for psychiatric disorders and epilepsy

Some people follow a keto diet for reasons other than weight loss. For example, people with epilepsy have used the ketogenic diet for many years to help reduce the number and severity of seizures.

Doctors also have tested whether the diet could help minimize the symptoms of psychiatric disorders, such as:

  • schizophrenia
  • bipolar disorder
  • anxiety

Experts believe that these disorders may be partly due to changes in metabolism that affect the brain. Examples include:

  • changes in the release of brain chemicals called neurotransmitters
  • increased inflammation
  • abnormal glucose metabolism in the brain

Some experts theorize that the metabolism-altering effects of EKs may help treat these disorders. However, few studies have investigated this idea.

A 2019 review of the available research suggests that EKs affect levels of certain neurotransmitters within the brain, thus reducing some of the signs of psychiatric disease.

The review authors conclude that using EK supplements to help the body enter ketosis may be an effective treatment for psychiatric diseases.

Photo: Stocksy/Ann-Sophie Fjelloe-Jensen

How to use exogenous ketones

There are a few different scenarios in which exogenous ketones can be extra helpful. For one thing, when you’re first transitioning to a low-carb/high-fat diet, you’re at risk for experiencing the keto flu, says LeVeque. “There’s a period in the beginning when you’re trying to get into ketosis that sort of sucks,” she says. (It’s all part of your body learning to thrive on a new fuel source.) “You may feel a little bit lightheaded, because you’re used to having carbs.” Her clients have found that taking ketones makes this process a little easier.

LeVeque says ketone supplements can also be a powerful way to curb cravings, since they’re a natural appetite suppressant. “If someone seriously wants to do ketosis, I have them taking two packets of ketones a day—one between breakfast and lunch, and one between lunch and dinner,” she says. “It’s the perfect bridge snack to add fuel to your brain. Or other people will use them as a way to intermittent fast until lunch time, as a support tool with Bulletproof coffee or eggs and avocado.”

And once you’ve been eating keto for a while, Dr. Crawford says exogenous ketones can help you bounce back into fat-burning mode following a carb-heavy meal. (This is good for your gut health, she says, since a lack of dietary fiber may disrupt the mucus and microbiome in the gut.) “Every two weeks I advise my patients to have a high-carb dinner; other physicians recommend having a high-carb day,” she says. “If you’re taking ketones, the next morning you can go right back into ketosis.”

Just make sure you’re buying the cleanest ketones possible, Dr. Crawford warns. “Look at the label—there’s a lot of junk in some of these powders, like artificial colors and flavors,” she says. “You want something that’s non-GMO, GMP-certified, and as pure as you can get.” Basically, the same kind of rules that apply to the grass-fed ghee in your butter coffee—the OG keto diet hack.

The keto diet may also have some mental health benefits, according to recent research. Here’s what happened when one Well+Good editor tried it for anxiety.

What Are Ketones and Are They Healthy?

If you are up on your health news or follow anyone in the health field, you have likely heard the term ketogenic diet. The goal of the ketogenic diet is to adapt the body to utilize fat as its primary fuel source instead of sugar. The body does this by first converting fat into what are called ketones that the cells can then burn as fuel. It is at this point that I typically get asked, what are ketones?

In this article, I am going to clear up any gaps, explain exactly how ketogenisis works, and why it can be so beneficial for the human body.

Biological Role of Ketones

For our ancestors, eating three meals a day just wasn’t a thing. Instead they would hunt and forage for the foods they could find. When there wasn’t food, they wouldn’t eat.

What this means is that sometimes they would go for days at a time with no food. To sustain life during times of scarcity, the body is thought to have developed the ability to utilize fat as an alternative fuel source.

In a traditional nutrition course, you would learn that sugar is the body’s primary fuel source while fat is a secondary fuel source. When sugar stores are burned up, the cells then convert to burning fat as an energy source. What we are finding out now is that fat can actually be a healthier and more sustainable source of energy.

Our Society Is Full of Sugar Burners

Modern day, we have an abundance of food that is available to us at all times. Most of us regularly eat three meals a day with intermittent snacking in between.

This kind of frequent eating, along with an overemphasis on carb-rich and sugary foods, causes a reduced ability to burn fat. As these foods damage our bodies on a metabolic level, we actually lose the ability to produce ketones.

This type of reliance on sugar creates massive blood sugar spikes, inflammation, hormone imbalance, and ultimately many of the chronic diseases that plague our society today. Luckily, by adopting a more ketogenic style of eating, we can reverse this damage and revert back to the efficient fat-burning machines we were meant to be!

The Advantage of Ketones

The energy currency of the body, comes in the form of Adenosine Triphosphate (ATP). The mitochondria within every cell in the body either metabolize glucose or ketones to form this important energy molecule.

Based on what we understand of cellular energy metabolism, ketones are able to create much greater amounts of energy per molecule than glucose. This means when the body begins to convert fat into ketones, you actually have a much more stable and sustainable energy source.

At the same time, burning fat does not create the same insulin and blood sugar response that burning sugar does. This is part of the profound benefits of being in ketosis including, improved hormone balance, lowered inflammation and improved brain health.

Likewise, many people report feeling much more stable when they go into ketosis. Feeling less hungry, gaining control over cravings, and often experiencing a much more stable emotional state.

How The Body Gets Into Ketosis

As I mentioned already, the body will either burn sugar or fat for energy. Sugar is converted into glucose while fats are converted into ketones by the liver. When blood sugar drops and glycogen stores are burned up, the body begins to convert fat into ketones for energy.

As we find out more about the benefits of ketones, people are intentionally putting themselves into this state for therapeutic benefits as well as a heightened state of mental performance.

There are several ways to promote an increase in ketone bodies, outlined below. The general strategy is to supply the body with ample fats while depleting blood glucose to signal the metabolic shift towards fat-burning.

Types Of Ketones

Unlike the simple conversion of sugar into glucose, fatty acid metabolism actually results in 3 different types of ketones:

  1. Acetate (Acetone)
  2. Acetoacetate (AcAc)
  3. Beta Hydroxybutyrate (BHB)

BHB, based on its molecular structure, is not really a ketone. Yet its presence is part of the beneficial effects of being in ketosis. Among its benefits is the ability to modulate BDNF in the brain and stimulate the growth of new neural tissue (1).

AcAc is the primary ketone body and is either converted into energy or BHB. Acetone exhibits the least metabolic effect and is mostly broken down and excreted through the breath and urine. The acetone excreted through the breath is actually responsible for the “keto breath” that some people experience in the beginning stages of keto adaptation.

Measuring Your Ketone Levels

When the body produces ketones, some are used for energy while the rest are circulated or excreted. Because of this, ketones are measurable in the blood, the saliva, and the breath.

Different ketones are measurable as follows:

BHB: In the blood

Acetone: In the breath

AcAc: In the urine

Although ketones can be measured in different ways, not all of them are quite an accurate representation of the body’s true ketogenic state. This is why most experts rely on the measurement of BHB through the blood as the ideal method.

Although this sounds invasive, new technology has actually made performing ketone measurements at home fairly simple and cheap.

BHB: Blood Measurement

As I said already, blood measurement for BHB is considered the most accurate depiction of the ketogenic state. This is performed in a similar fashion to blood sugar testing.

Many of the blood glucose monitors on the market also have the ability to read blood ketones. Using a different type of testing strip, all you have to do is prick your finger, collect a small sample of blood, and place it into the monitor for a quick ketone measurement.

The monitor I usually recommend is this Precision Xtra monitor.

The ranges you are looking for here are as follows:

Very Low Ketone Levels: Less than 0.5 mmol/L

Mild Ketosis: 0.6-1.5 mmol/L

Optimal Ketosis: 1.6-3.0 mmol/L

Very High Ketone Levels: Greater than 3.0 mmol/L

Although mild ketosis can be achieved rather quickly, it can take up to 2-3 weeks to enter an optimized ketogenic state (2).

The only downside with blood ketone measurement is that the testing strips generally run for about $4 per strip. To perform daily ketone measurements using this method you would be looking at around $120 per month on just testing strips!

Acetone: Breath Measurement

For a ketone measurement that doesn’t require a blood draw or the recurring expense of test strips, breath ketones are also a reliable measurement (3).

Using a device such as this Ketonix breath analyzer, you can perform a simple ketone measurement anytime you need. Although this device will run you for about $190, over time it will likely be a more economical option compared to blood testing since it is only a one-time fee.

It is important to note that while breath ketone measurement is mostly reliable, factors such as alcohol and water consumption may influence your measurements. Luckily you can take multiple measurements throughout the day to get a better idea of your average ketone levels.

Using the Ketonix breath ketones measurement, the device will light up different colors depending on your state of ketosis. Based on the chart below you would want to be in the yellow or red zone for optimal nutritional ketosis.

AcAc: Urine Measurement

The body releases unused acetoacetate through the urine upon which it can then be measured using special testing strips. This is a simple option that is also very cost effective at about $10 per 100 strips.

Although simple and cheap, urine measurement of ketones can be somewhat unreliable. This measurement will allow you to see if your body is producing ketones, it doesn’t necessarily provide any insight into how well your body is utilizing ketones for energy.

Additionally, urine ketone measurements can vary significantly depending on the individual’s hydration levels. For example, dehydration will make ketone levels appear higher, while over hydration will make them appear lower.

During the beginning phases of keto adaptation, the body has a poor ability to utilize ketones as energy. Even if the body is producing ketones, most of them will be excreted. Once the body becomes keto-adapted, higher amounts of ketones are used as energy and less are excreted naturally.

So if you were to choose urine measurement for ketone analysis, I would recommend measuring daily from the very beginning of your eating plan. You should notice an initial increase in ketones into the high range followed by a gradual decrease as you become keto adapted.

Although your ketones will be high, you will actually be hypoglycemic until your body learns to utilize ketones effectively. As you become keto-adapted you should look for a drop in urine ketone levels between 2-3 weeks of eating a ketogenic style diet.

This drop in urine ketone levels lets you know that your body is becoming more efficient at actually using them for energy.

Concern: Ketoacidosis

The state of nutritional ketosis is sometimes confused with a state referred to as ketoacidosis. Ketoacidosis is an extreme ketotic state that occurs mostly in diabetic populations. When an individual is unable to produce insulin, sugar cannot get into the cells. As a response, the body drastically upregulates ketone production.

In this state, there is both an extremely elevated blood sugar and blood ketone level simultaneously (4). This will cause the overall pH of the body to drop to a dangerously acidic level which can be fatal. While this condition can be harmful for the individual, it is important to note that entering this state is actually very rare.

To put this into perspective, this condition mainly occurs in unmanaged diabetics. In this state, ketone levels will reach 20 mmol/L and beyond. An otherwise healthy individual could water fast for 20 days and still maintain a ketone concentration below 20 mmol/L.

In other words, unless you are diabetic, reaching a state of ketoacidosis through diet alone is virtually impossible.


Ketones are the body’s alternative fuel source to sugar. Derived from fatty acids, they provide a much more long-lasting and stable production of energy. In addition to providing stable energy, ketones also do not promote the inflammatory rise and fall of insulin as does sugar.

Modern dietary habits have altered our metabolism and made sugar our primary fuel source. By following a ketogenic style of eating, it is possible to reverse these metabolic defects and take advantage of the benefits that ketones have to offer for our brains and bodies!

Sources For This Article Include:

2. GF Cahill Jr, T. A. (1971). Starvation and body nitrogen. Transactions of the American Clinical and Climatological Association, 82, 42–51. PMID: 4934018

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Exogenous ketone supplements:
Do they work?

I also chatted to some Prüvit reps, who told me that it might be necessary to keep taking the supplements for a couple of months to start to see more elevated ketones. Well, the proof is in the pudding (or in this case, in the fluorescent-coloured, artificial-tasting pink drink). But I would hesitate before spending money on a two-month supply just to find out if that’s true. Real Ketones’ Kegenix Prime was associated with a decrease blood ketones. Not a good start, and we’ll get back to this point later.

Other markers

For many of the other markers, the ketone supplements performed pretty poorly, especially for physical performance!

The ketone supplements were associated with a 5.4% decrease in physical performance while the artificially-sweetened, non-caffeinated beverage I used as a placebo was associated with a 20.3% increase: a big difference in favour of the placebo. Before you go rushing out to buy some, remember that this experiment was not performed under fully-controlled, laboratory conditions, and we were working with too small a group to prove that the placebo caused an increase in physical performance. But what we can say is that we couldn’t find any correlation between ketone supplements and an increase in physical performance in this experiment. According to Brianna Stubbs, some of the work currently being done on new kinds of ketone salts is starting to show more promise in relation to physical performance, so there may be better news on this down the line.

There were small improvements in mental performance and moderate improvements in mood. There was a 1.25% greater increase in mental performance with the supplements than the placebo and a 17.6% greater increase than the placebo in mood.

There was not much difference at all in perceived mental clarity between the supplements and the placebo.

Energy levels decreased in the testing with the ketone supplements.

Really, though, these small changes do not seem particularly significant to us. We would have needed to see much bigger increases across numerous markers to persuade me that the supplements are worth spending money on.

Satiety decreased in both cases, slightly less with the supplements than with the placebo: participants reported feeling less hungry after taking the supplements than after taking the placebo. However, we are doubtful whether this would be enough of a difference to impact food intake and therefore induce weight loss indirectly, compared to not taking a supplement at all. Especially since, as noted before, BHB switches off lipolysis.


In terms of taste, the placebo was the winner, with a taste score of 7/10 versus a combined 4.6/10 for the supplements. One of the reasons that exogenous ketone supplements need to be sweetened is that the ketones themselves taste pretty bad (this is one of the reasons why it is difficult to market ketone esters).

The following graphic shows how Diet Doctor team members rated the different supplements on taste:

Taste scores for the placebo and different supplement brands

The results for Kegenix Prime: Exogenous ketones exposed?

The results for Kegenix Prime deserve a special mention.

First, it is interesting that the Kegenix Prime supplement scored so high on taste (nearly as high as the placebo). The Kegenix Prime supplement showed, in our experiment, to be ineffective at raising blood ketones. In fact, on average blood ketones dropped by 0.03 mmol/L with this supplement.

Could the better taste of the Kegenix Prime and the lack of effect on blood ketones mean that Kegenix Prime doesn’t really contain much BHB at all? Remember that Kegenix Prime has a “proprietary blend” that doesn’t tell you how much BHB is in the supplement. It certainly makes you wonder…

Second, take a look back at table 2. Kegenix Prime scored as the “winning brand” for 4 out of the 7 markers tested: mental performance, satiety, mental clarity and energy. Compared to the other supplements, it also scored highest for physical performance, although none of the supplements were listed as a “winner” since the placebo outperformed them all for that marker.

BUT, the Kegenix Prime did not even raise blood ketones! The participants’ ketones went down by an average of 0.03 mmol/L in our testing. This really raises the question we brought up in the section on the potential problems with the supplements: the other ingredients added to the supplements.

The fact that the supplement that did not raise blood ketones is also the one that outperformed the other supplements for so many of the markers, really does suggest that any effects that the supplements do have may well be down to the other ingredients that the supplements contain.

The verdict

I don’t think we even need a drumroll here… Based on my background research into ketone-supplement companies, the survey of Diet Doctor users and the experiment itself, we cannot recommend taking these supplements. I can personally think of many more beneficial ways to invest money in my health, such as buying grass-fed meat and organic vegetables, or even buying a bicycle and riding it outside in the sunshine.

Importantly, at Diet Doctor we do not think you need to spend any extra money at all in order to revolutionize your health. You can achieve radiant health just by enjoying authentic food that is naturally low in carbohydrates, getting plenty of sleep and some exercise (going for a walk is free) and reducing stress. A lot of you who answered the survey made exactly these points in your explanations of reasons for not taking the supplements. I whole-heartedly agree.

Of course, there may be some people who choose to take these supplements because they genuinely do feel they benefit from them. This is of course your choice and this article in no way aims to shame or criticize anybody. However, I do think that, for most people, eating a low-carb diet based on real foods is a lot more likely to be associated with the benefits that the supplements claim to provide than the supplements themselves.

As Dr. Ryan Lowery pointed out to me, ketone supplements could play an important role in the future for elite sports performance, for example, or for people with brain injuries who cannot metabolize glucose properly. I am encouraged that scientists are working to develop these possibilities and, as long as plenty of peer-reviewed scientific research is done into the products being developed, I could feel more positive about the ketone salts in the future. For now, that scientific support is lacking.

Dr. Brianna Stubbs made another important point when I interviewed her about the science on ketone supplements. She told me:

It is important to define what it means to be “in ketosis”. If being “in ketosis” means having ketones in your blood, then of course ketone supplements get you into ketosis. But that is different from being in an endogenous ketogenic, fat-burning state as a result of following a ketogenic diet. Getting this distinction right will go a long way towards stopping ketone salts companies from using misleading marketing about the issue. We need to reach a consensus about what being “in ketosis” means and then force companies to use that definition.

I think the key point here is misleading marketing, and this goes for all commercial food and health products, not just ketone supplements. Being a conscious consumer means being aware and critical of the marketing schemes that companies use.

It is important to keep a clear head and not be taken in. To stay objective and be aware that when a company appears to be providing you with “information”, it may well just be using clever marketing to make you buy a product.

Ketone Salts: Ketosis with a Cost

With the increasing excitement and emerging scientific research surrounding keto, more and more people are trying out the high-fat, low-carb diet for body composition and exercise performance. Maybe you’re one of them!

While the health benefits are promising, you may have also found that maintaining a state of ketosis can be extremely difficult, especially with the Western diet’s love affair with carbohydrates.

If that’s the case, you may want to consider optimizing your keto diet. Supplements could be a great tool that can help you get into a deep state of ketosis faster than dieting and / or fasting alone.

The most widely-available keto supplements on the market are exogenous ketone salts, which are formed when ketones (energy-generating molecules derived from fatty acid breakdown) are bound to a mineral ion. Let’s assess some of the nuances around ketone salt supplements and other types of exogenous ketones to help you make the best decision for optimizing ketosis.

Ketones 101

Before launching right into ketosis, it’s important to understand the science behind ketones themselves.

Ketones are a fundamentally different fuel source than the carbohydrates, fat, and protein that our bodies typically rely on for energy. A highly efficient energy source, the body produces ketones when pushed to its limits – either during extreme carb restriction1 or after heavy exercise.2

Achieving Ketosis

Ketosis is generally defined as elevated blood ketone levels greater than 0.5mM.1 There are two types of blood ketones: endogenous and exogenous ketones. Both ultimately can get you into a state of ketosis, albeit through very different methods.

Endogenous ketones are produced by the liver, usually when someone is in a fasted state or on a ketogenic diet. The production of endogenous ketones can take weeks or months of strict dieting.1 But there’s a payoff to that patience: your body ends up becoming fat-adapted; learning to use fat as fuel when carbohydrate intake is depleted. This process is sometimes referred to as nutritional ketosis.

Taking exogenous ketones can deliver a fast-acting, deep state of ketosis almost immediately.

Exogenous ketones are often consumed as a dietary supplement or through food consumption. They can put you in a state of ketosis,3 but the body isn’t “technically” ketogenic because the ketones were delivered from an external source (meaning, the body didn’t produce from fat them itself). Exogenous ketones don’t trigger natural ketone production, but they still lead to elevated blood ketone levels.

Different Types of Ketone Bodies

The three primary ketone bodies are beta hydroxybutyrate (BHB), acetone, and acetoacetate (AcAc). Most exogenous ketones products utilize BHB rather than AcAc because BHB is more stable and easier to make into a sellable product while acetone is considered to be a waste product of fatty acid breakdown.

Acetoacetate is created in the liver from the breakdown of fatty acids, and is then mostly converted into BHB for transport in the blood. Any AcAc in the blood can be either taken up into the cells or spontaneously broken down to produce acetone–which cannot be used for energy production. Acetone is removed from the body through waste product like urine, or through the breath.

BHB is the ketone body present in the blood at the highest level when produced naturally.4 This is because it doesn’t spontaneously degrade like AcAc .

Once taken up into the cells from the blood BHB offers the advantage of being reduced easier than AcAc. This means that when BHB is converted into AcAc inside the cell’s mitochondria, it generates NADH–a coenzyme needed for ATP production. AcAc whiffs on the energy-providing power of NADH. Plus, when an AcAc-based supplement is consumed, the body will reverse-convert some of to BHB, which actually uses up those NADH molecules.

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Exogenous Ketones: Salts, MCT and Esters

We’ll first explore ketone salts before analyzing some potentially more effective alternatives.

Ketone Salts

Ketone salts typically come as a powder containing BHB bound to a mineral salt (usually either sodium, potassium, or calcium) or an amino acid (like lysine or arginine). These powdered BHB salts are commonly dissolved in liquid to be consumed in drink form.

Despite the lack of published work analyzing the effects on biomarkers or performance measures in humans, ketone salts are a growing market. It is important to note that the FDA doesn’t recognize ketone salts as GRAS (Generally Regarded as Safe) food ingredients.

Many studies have been conducted in rats5,6,7 and have shown relatively low levels of BHB in the blood. Human studies showed similar results, with clinical trials reporting blood BHB levels of 0.6 – 1 mM after ketone salt drinks.8,9,3

One recent study in young adults illustrated the differences between salts and esters (more on these later) acutely: ketone salts provided a peak D-BHB of 1 mM whereas the same amount of BHB in a ketone ester raised blood BHB levels to 2.8 mM.3

For performance, data has been mixed at best. Four studies investigated the effects of ketone salts in athletes (total n = 22) with none of the studies finding significant improvements in performance markers.8,9,10,11 In one study, performance actually decreased by 7%, and GI distress (ranging from nausea to diarrhoea to vomiting) was reported in a high percentage of athletes.10,12

While ketone salts are relatively inexpensive and may be a nice co-deliverer of other nutrients, BHB levels are only raised slightly–to 1 mM.8,9 ,3 There are also some health concerns with consuming enough salt to raise BHB significantly.

Excessive salt consumption may have long-term health implications.

High salt intake is linked to hypertension, cardiovascular disease and even stomach cancer.13 The 2015 – 2020 Dietary Guidelines for Americans recommends 2,300mg of salt consumption a day; but most Americans consume 3,400mg daily. Some ketone salt products contain nearly 70% of the recommended daily allowance of sodium in a single serving.

A perceived benefit of ketone salt supplementation is a potential replacing of lost electrolytes. Electrolytes loss is a common problem in the early weeks of the keto diet. However, electrolyte imbalances usually don’t persist after keto-adaptation period of about 28 days,14 and so then excessive salt consumption may still be harmful.

Let’s review: ketone salts provide sub-optimal BHB, have no effect on performance and may cause significant GI issues. That could be why some makers of ketone salts have cited studies conducted on ketone esters.

So if not salts, then what other options do you have to increase ketones exogenously? Here are two, which have shown varying degrees of success.


OK–you caught us. MCT oils don’t actually contain ketones. They’re medium-chain triglycerides (MCT) fat molecules made of glycerol joined to three medium-length fatty acid chains that are between 6-12 carbons in length.

So where do the ketones come from? Ketone generation results from the breakdown of MCTs by the body. They’re processed differently than long-chain fats, which are absorbed and released into the blood via the lymphatic system, bypassing the liver (where ketones are produced). Instead, MCTs are transported straight to the liver in the blood, where they’re either used directly for energy or turned into ketones.

MCTs exist naturally in some foods such as coconut oil and dairy products. But a high amount is required to increase blood BHB. Studies on MCT supplements report that blood ketone levels following MCT use were relatively low (0.5 – 1mM).15 However, the consumption of large amounts of MCTs can cause gastrointestinal side distress.15,16 Additionally, people who are trying to loose weight should watch out for MCTs (specially if supplementing with MCT powders) as they are highly caloric.

While MCTs aren’t exactly exogenous ketones, they do provide a substrate by which one could potentially increase blood ketone levels.

Ketone Esters

Ketone esters are salt-free liquids that contain BHB without any extras. Instead of being bound to a mineral, like BHB salts, they’re bound to a ketone precursor (like butanediol or glycerol) via an ester bond. You can tell how many ester bonds there are from the name: monoester (one), diester (two), or triester (three).

They aren’t exactly a new discovery either. The first ketone ester was developed in the late 70s, and other types were developed in the mid-90s.17,18

There are a couple types of ketone esters being developed and sold right now with each affecting the body differently.

An AcAc diester was developed at the University of South Florida. In rodents, it increased blood D-BHB to 1 – 4mM, and blood AcAC up to 5mM.19 Animal studies have also shown that it might help with seizures,19 weight loss,20 and cancer.21 A published study in humans, however, identified a 2% decrease in a 31km cycling time trial performance. The lack of efficacy was potentially thought to be due to low levels of BHB (less than 2mM), the short high-intensity nature of the time trial, and / or the use of AcAc vs. BHB.22,23

The D-BHB monoester raises blood ketones to exceptional well, roughly a 3 – 6 mM increase within 30 minutes of consumption.3,24,25,26 This means you enter into a state of ketosis faster than other products currently on the market. It was developed over the course of 15+ years by DARPA, the NIH, and University of Oxford.

And it’s salt free so it won’t impact water retention or pose any of the health risks often associated with high salt levels. Side effects of the ester itself are also minimal. A single does of D-BHB mixed with a meal replacement formula reported very little gastrointestinal issues at typical doses and only caused mild symptoms when taken at 4x the recommended amount.24

Ketone esters have proved beneficial for endurance performance also.27,26 Athletes using ketone ester drinks before a workout reported no major side effects hindering performance. This is in contrast to ketone salts and the acetoacetate diester which have reported side effects (GI issues) that hampered performance.23 There have been published clinical trials in humans demonstrating the efficacy of ketone ester drinks on improving performance, recovery and several health outcomes such as appetite control,3 blood glucose management28 and even neurodegenerative disease.29

And while list of benefits of BHB monoesters runs long, for now, taste is not on that list. We’ve heard it “tastes like it works,” which is a polite way of saying that the taste is distinct and strong. But for athletes, a single bitter sip is worth the performance benefits. Certain ketone esters have FDA GRAS (generally regarded as safe) status as a food, are cleared for use in athletes by the World Anti Doping Agency (WADA), and are batch tested as part of the NSF Safe for Sport program.

For performance and recovery, human studies on ketone esters have demonstrated extremely positive results.

When consumed before exercise, the D-BHB from helps muscle work 28% more efficiently than carbs alone. This means that the body does more work with the same amount of oxygen.30 In a 30-minute time trial test in which cyclists consumed the D-BHB ester before exercise with carbohydrates, riders’ performance improved by 2-3% (400m).26 When taken after exercise with glucose, the D-BHB ketone ester also improved the rate of resynthesis of glycogen as well as the rate of muscle protein synthesis.27,31

There’s also some exciting research emerging around the cognitive benefits of ketone bodies (because ketones can cross the blood-brain barrier). The D-BHB ketone ester has been shown to help mice solve maze puzzles 38% faster than normal32 as well as shown to improve cognitive performance in a simulated soccer trail.10

Are Ketone Salts Right For You?

While deciding which exogenous ketone supplement is best for you depends on a number of factors, it ultimately lands on what goals you’re looking to achieve.

Ketone salts are less expensive than ketone esters, and do provide a mild boost in ketone levels. They have a milder taste that is easier to mask with artificial sweeteners, like stevia and other natural flavors. However, the science behind ketone salts is still lacking, with no clear evidence for weight loss, cognitive ability or improved performance. In fact, in some cases, performance decreased due to overwhelmingly negative side effects.

While the taste of some ketone esters leaves something to be desired, the data pointing to increased performance in human studies makes it worth while to investigate as a potential ergogenic aid.

If you’re an athlete or dieter considering an exogenous BHB supplement for physical performance or nutritional support, evidence-based results are best for helping highlight how exogenous ketones might affect you. Ultimately, you’re choice of supplement should be based on your budget and personal needs.

Have you used BHB salts? Have you tried esters? Let us know your experience in the comments.

The best keto products, ranked

Here’s our list of the supplements and foods that can help supercharge your keto diet.

Researchers believe that humans, and many other animal species, too, developed the capacity to produce ketones (or ketone bodies) in order to prolong survival during periods of caloric deprivation. (1) Ketones are beneficial for our muscles, brains and other tissues during times of stress — such as when we’re intentionally restricting calories because we’re fasting, cutting out carbohydrates from our diets or doing endurance exercise. (2)

What is a ketone supplement exactly, and what would be the purpose of using one? Ketones are considered the most energy-efficient source of fuel for the body, releasing high amounts of ATP (adenosine triphosphate), which is often referred to as “the energy currency of life.” Not only can your body make ketones in response to things like fasting or very low-carb, very high-fat dieting, but you can also acquire ketones from exogenous ketone supplements.

Exogenous ketones, such as ketone esters and BHB salts, help to amplify the many positive effects of the ketogenic diet — while also mitigating “keto flu” symptoms like fatigue and brain fog.

Other benefits associated with ketone supplements include:

  • helping you to shed excess weight
  • controlling hunger and cravings
  • supplying your brain with an energy supply, which boosts cognitive performance
  • helping you to perform physically and recover more easily from exercise

What Are Exogenous Ketones? What Do They Do?

Exogenous ketones are ketones supplements that come from outside the body. What do exogenous ketones do? Exogenous ketones mimic the effects of ketones that are naturally produced by our bodies under certain circumstances. The liver naturally produces endogenous (meaning inside) ketones while in the metabolic state of ketosis, while exogenous (meaning outside) ketones are those provided from supplements.

What are ketones exactly? Ketones are defined as intermediate products of the breakdown of fats in the body. When you follow a very-low carb, very-high fat diet — also known as the ketogenic diet — your body starts producing organic ketone compounds, which serve as an alternative fuel source to carbohydrates. Basically, the keto diet fires up your fat-burning capacity by changing the way your body utilizes energy.

Ketones (or ketone bodies) are made when:

  • Someone is following the keto diet (also referred to as a very-low carb ketogenic diet, or VLCKD), which puts them in the metabolic state called ketosis. Most low-carb diets will not lead to increased ketone levels, only the ketogenic diet can effectively do this. To stay in ketosis you need to get 70–80 percent of your daily calories from fat, no more than 20–25 percent of calories from protein, and no more than 5–10 percent carbs of daily calories from carbohydrates.
  • Someone is fasting for 16 hours (intermittent fasting) or more, or purposefully restricting their calorie intake.
  • Or if someone is starving.
  • Ketone production is also boosted by high-intensity/endurance exercise, especially if it lasts more than 60 minutes.

The human body produces three types of ketones: (3)

  • Beta-hydroxybutyrate (BHB) — accounts for roughly 78 percent of total ketones in the blood.
  • Acetoacetate (AcAc) — accounts for approximately 20 percent of ketones in the blood.
  • Acetone — accounts for only about 2 percent of ketones in the blood.

Beta hydroxybutyrate (or BHB) is the most abundant type of ketone that we produce, helping to provide the bulk of energy when our diets are nearly devoid of all carbohydrates. While there’s three types of ketone bodies, the ketone found in exogenous ketone supplements is usually only or mostly beta-hydroxybutyrate (BHB).

Exogenous Ketones Benefits & Uses

Exogenous ketone are usually taken to boost the effects that the keto diet and intermittent fasting have to offer. Exogenous ketone bodies have functions and benefits that include:

  • Helping you to get into ketosis more quickly
  • Mitigating side effects associated with ketosis, such as irritability, headaches and fatigue
  • Supporting weight loss, especially fat burning
  • Improving metabolic pathways, including preventing or treating diabetes and insulin resistance
  • Suppressing your appetite
  • Fighting cancer
  • Reducing anxiety
  • Helping to protecting the brain and cognitive health, including decreasing the risk for neurodegenerative diseases
  • And potentially increasing lifespan/longevity

Here’s more about how exogenous ketones can support both physical and cognitive health:

1. Helps You Transition Into Ketosis

You can use exogenous ketones to help you transition into ketosis (the metabolic state where your body is using fatty acids for its primary source of energy) more easily and quickly, since ketone supplements supply your body with a direct source of ketones that are easily used as fuel.

Once you’re in ketosis, you’ll experience benefits including: more stabilized blood sugar, reduced hunger/cravings and help with loss of excess body fat. If you take a break from the keto diet (let’s say you’re carb-cycling, for example), then you can use ketone supplements for support transitioning back the diet.

Taking a ketone supplement may also help you avoid keto flu, the cluster of symptoms that occurs when the brain has no glucose for energy and before the liver is producing generous amounts of ketone bodies. Keto flu can lead to diarrhea, cramping, nausea, constipation, bad breath, overall weakness and rash, but these symptoms abate after you’re in ketosis (or when you supplement with ketones). (4)

2. Can Help With Fat-Burning & Weight Loss

How do ketones help burn fat? As mentioned above, they’re beneficial for getting you into ketosis. However, taking ketone supplements may not lead to weight loss if you aren’t also following a very low-carb ketogenic diet.

In other words, ketone supplements are helpful for keeping you in ketosis, but they aren’t a magic bullet when it comes to weight loss. You will still need to track your fat, protein and carbohydrate intake (at least at first) to make sure you’re actually in ketosis and burning fat. Once you have a good idea of what it takes to stay in ketosis, you can use exogenous ketones to keep your energy up and to decrease symptoms that mess with your success, such as fatigue and cravings.

You may also use exogenous ketone supplements to deepen your level of ketosis while practicing intermittent fasting, as your body begins to product some ketone bodies after 12 hours of fasting.

3. Can Improve Energy Levels & Prevent Fatigue

Exogenous ketones can be used to help improve energy levels, power output, physical performance and recovery from exercise. (5)

In some animal studies, researchers use ketone esters to increase rats’ blood ketone levels and to test the effects on their physical performance, cardiovascular functioning, and more. In one study, when rats were given chow (food) that was supplemented with the ketone ester called (R)-3-hydroxybutyrate that accounted for 30 percent of their daily calories for five days, the rats could run 32 percent further on a treadmill compared to rats eating a diet supplemented with either equal amounts of corn starch or palm oil. (6)

4. Help to Decrease Brain Fog & Improve Mental Performance

When glucose is not available from your diet, fatty acids as well as ketone bodies can be metabolized by the brain. Studies have found that ketones benefit cognitive/mental health by: improving cognition in memory-impaired adults, focus, attention and learning, (7, 8)

In the same rat study mentioned above, ketone-fed rats were able to complete a maze test 38 percent faster than rats fed the control diet because they made significantly more correct decisions prior to making a mistake.

Ketones may also prevent the formation of free radicals in the brain that can damage mitochondria can contribute to neurological problems. (9)

5. Helps Improve Metabolic Functions

In certain animal studies, giving exogenous ketones to rats has been shown to decrease blood glucose and insulin levels, even when the rats are eating highly processed diets high in refined carbs like corn starch. (10) Ketone esters are also used to raise ketone levels while simultaneously lowering cholesterol and triglyceride levels.

6. May Fight Some Cancers

A newer branch of research on ketone supplements, there is some hefty research completed in animals that suggests exogenous ketones (both with or without adherence to the keto diet) may help slow or stop the growth of cancer. When animals with metastatic (late-stage, multi-organ) cancer are given ketone supplements, they seem to survive up to 69 percent longer than control subjects. (11)

This may be due to the effect of both the ketogenic diet and ketone supplements to independently influence the Warburg effect, a little-understood action that aids the growth of cancer cells. (12)

7. Could Reduce Anxiety

Research studies have found that exogenous ketone supplementation may reduce symptoms of anxiety, even when the animals were not following a ketogenic diet. (13)

8. Helps Regulate Blood Sugar

Again with or without a keto diet, ketone supplements help to decrease blood glucose levels, suggesting that they may be helpful for diabetics. (14)

9. Improves Exercise Performance and Recovery

Have you ever heard that ketosis makes it harder to perform physical tasks or work out? Nothing could be further from the truth! In fact, entering a state of ketosis has no noticeable impact on even high-intensity exercise performance. (15)

But the news gets better — exogenous ketones may actually increase both exercise performance and muscle recovery. (16) This could be particularly helpful for high-intensity athletes who wish to follow a ketogenic lifestyle.

Types of Exogenous Ketones: Ketone Salts & Ketone Esters

There are three main types of ketone supplements:

  • Ketone salts (sometimes called BHB salts), which are ketones that are bound to minerals, including sodium, calcium, magnesium or potassium. (17) The minerals in ketone salts can actually help to decrease keto side effects, such as muscle weakness and digestive issues. Ketone salts are typically the type used in powdered ketone products, which contain some combination of BHB, sodium and other ingredients.
  • Ketone esters, which are basically “raw ketones” that metabolize quickly into BHB. This type is not widely available for most consumers but is typically used in research/studies. While esters have the benefit of raising blood ketone levels quickly, they are also notorious for tasting terrible and causing unpleasant digestive issues. However, new ketone ester products are now hitting the market that claim to taste better and work rapidly. (18)
  • Ketone oils, which can include MCT oil. MCT (medium chain triglyceride) oils are used to boost ketones and help with fat burning. They may also support training, exercise performance and growth of lean muscle mass. (19) Coconut oil also contains medium chained triglycerides, but MCT oil is a more concentrated source. MCTs must be broken down first before they can be used for energy, making this type of supplement slightly less effective than ketone salts or esters.

Beta-hydroxybutyrate is the most active type of ketone body that can be used by your tissues for energy, so that is the ketone that most exogenous ketone supplements aim to increase.

Ketones can be taken in various forms including: capsules, oils, powders or drinks. No matter which type you use, it should be able to help raise BHB levels by supplying you with an immediate usable source of ketones. Some products will provide medium-chain triglycerides (MCTs) to help with your natural production of ketones.

Products may also contain other ingredients that support ketosis and decrease keto flu symptoms, such as bone broth, caffeine, coffee or coffee extract, apple cider vinegar, spices, collagen, probiotics and/or adaptogen herbs like ashwagandha. Because powdered ketone supplements don’t tend to have the best taste, other ingredients like cocoa, vanilla extract or stevia may be used to enhance the flavor.

Different ketone products also vary in terms of their calorie and macronutrient content. Some contain only fat, while others provide an ideal ratio of both fat and protein with very minimal carbohydrates (this is typical of some powdered products that are used to make ketone drinks/smoothies/shakes). One advantage of using capsules and powdered ketone products is that they are easy to travel with, shelf-stable and can be mixed with other ingredients to make their taste more appealing.

Exogenous Ketones vs. MCT Oil

The very best foods for increasing natural ketone production are healthy fats — especially MCT oil, butter, and coconut oil.

  • MCT oil is a very popular food/supplement among people following the keto diet because it can be used to quickly increase fat intake, boost natural ketone production, increase energy, support digestive health, and reduce appetite and cravings.
  • MCT stands for “medium chain triglycerides,” which are a type of fat that your body is capable of breaking down into ketones easily and quickly. Coconut oil contains MCTs (as do some other foods like cheese, butter, whole milk and yogurt) but not as much as MCT oil. MCT oil is a more concentrated source of medium chained fats, making it ideal for supporting ketosis.
  • MCT oil has an advantage over exogenous ketones when it comes to cost. It tends to be less expensive than many exogenous ketone supplements.
  • What are ways that you can use MCT oil? MCT oil can be taken just like a supplement, by having a tablespoon on its once daily. You can also add a tablespoon or more to your keto coffee in the morning, a shake or smoothie. It’s mostly flavorless but does add fattiness/creaminess to anything it’s mixed with. It tends to be easy to digest and can be better tolerated than some ketone supplements.
  • Many people choose to use emulsified MCT oil because it mixes well with beverages and does not have an oily residue. It tends to have a better flavor than certain keto supplements and is masked easily by other keto foods and ingredients.
  • While the most common way to consume MCT oil is in liquid oil form, there are now also some newer dried MCT oil powders available. These can be used like other exogenous ketone powders, such as added to keto shakes, smoothies or coffee.

How to Get Exogenous Ketones in Your Diet

How & Why to Use Exogenous Ketones:

By now it should be clear that the benefits of adding a ketone supplement to your routine include: helping with the transition into a state of ketosis, supporting energy levels when in a fasted state, preventing keto flu symptoms, and improving athletic/exercise performance and recovery.

Ketone supplements can be used in between meals or before a workout to provide you with a quick source of ketones. You can also use ketone supplements to help you get back into ketosis more easily and quickly if you’ve abandoned the diet for a period of time.

They can be taken with food or on an empty stomach, but may be more impactful if you take them on an empty stomach (such as first thing in the morning) or when fasting. If you’re using a powdered ketone supplement, try mixing one scoop/serving with about 12 ounces of water, plain almond milk, coffee or tea. Ketone drinks/smoothies can be enjoyed warm or cold.

Exogenous Ketones Supplementation & Dosage:

  • How you use exogenous supplements depends on your goals. Because there are many types of ketone products available that are used differently, always read directions and dosage recommendations.
  • You might use exogenous ketones for about 3–5 days while you’re transitioning into ketosis. Use about 1/2 to 1 serving (such as one scoop or 3–6 capsules) per day. Another approach is to try having smaller amounts/doses spread throughout the day so your body has a steady supply of energy coming in. Depending on the type of product you use, it might be recommended that you take 1/3 – 1/2 of a scoop/serving at a time, several times per day.
  • To help keep keto side effects to a minimum, you might decide to have one scoop of a ketone product in the morning, or to use half a servings 1–3 times per day.
  • For help with exercise performance and recovery, use one serving/scoop about one hour before a workout.
  • If you’re taking keto capsules, a typical dose will be about 6 capsules daily with 8 ounces of water. Capsules can be taken with or without food.

How to Balance Ketones on the Keto Diet

Remember, while ketone supplements may have a number of benefits, you can still naturally increase/optimize your own production of ketones, which may have more lasting health effects. Other than taking exogenous ketones, there are also dietary changes you can make and other lifestyle habits that increase ketone production. These include: eating a very-low carb, high-fat diet (aka the keto diet), fasting and doing intense exercise (especially if it lasts more than 90 minutes).

To really maximize ketone production and enhance effects like fat-burning, you can combine a ketogenic diet, intermittent fasting, exercise and exogenous ketones like ketone capsules, a powdered product or BHB salts.

If weight loss is your primarily goal, you’ll want to track your progress. What level of ketosis is good for weight loss?

  • The optimal range of blood ketone levels is between 0.6-6.0 mmol/L, depending on your goals and the condition you’re treating. When you’re not purposefully limiting carb take, levels will stay below 0.5 mmol/L.
  • Quality ketone products can help increase your blood ketone levels to as high as 1.5 mmol/L. Following a keto diet correctly can increase levels even more. Most people on the keto diet will have ketone levels between 2-3 mmol/L. (20)
  • For general weight loss, aim to get your ketone levels above 0.6 mmol/L.
  • Doctors may sometimes aim for higher levels of ketones in patients that are being treated for therapeutic purposes, up tp 3-6 mmol/L. (21) But with this level of ketosis, it’s best to be monitored and to work with a practitioner.

Precautions/Side Effects

Wondering if the keto diet is safe, and what potential side effects exogenous ketones might have? Side effects associated with ketosis can include: unpleasant taste in your mouth, fatigue, weakness, indigestion, dizziness, low blood sugar, sleep related issues, mood changes, frequent urination, constipation, cramps, and trouble exercising or recovering.

With time your body gets used to being ketosis and producing more ketone bodies, so symptoms should only be temporary and last for about 1–2 weeks. Ketone supplements should not make symptoms worse, but can sometimes cause loose stools/diarrhea. If this happens, decrease your dosage until you notice improvements. Be sure to drink enough water, rest and sleep enough, and to not over-exercise while you’re dealing with any keto side effects.

Final Thoughts on Exogenous Ketones

  • Exogenous ketones are ketones supplements that come from outside the body. Exogenous ketones mimic the effects of ketones that are naturally produced by our bodies under certain circumstances, including when following the keto diet or fasting.
  • Benefits associated with ketone supplements include: help transitioning into ketosis, help staying in ketosis, decreased keto flu symptoms, more energy, enhanced physical performance and recovery, and improved cognitive health/mental performance.
  • There are three main types of ketone supplements: ketone salts (sometimes called BHB salts), ketone esters and ketone oils (such as MCT oil). Ketone products some in various forms: liquid, oil, capsules, extracts or powdered mixes.
  • You can use exogenous ketones for about 3–5 days while you’re transitioning into ketosis, have smaller amounts/doses spread throughout the day so your body has a steady supply of energy coming in, have a scoop of a ketone product in the morning to help keep side effects away, or use one serving/scoop about 30 minutes to an one hour before a workout. If you’re taking keto capsules, a typical dose will be about 6 capsules daily with 8 ounces of water
  • Ketone supplements are usually well-tolerated, but some have an unpleasant taste. When used in high doses they may be cause diarrhea and GI issues, so start slowly and increase your dose depending on your reaction.

Read Next: Keto Diet for Women: Benefits, Food List & Tips to Overcome Side Effects

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