Side effects of licorice


Black Licorice Warning: Why FDA Says Don’t Eat Too Much on Halloween

One Halloween treat may be even worse for you than you thought, and not because of sugar and empty calories.

In a new warning, the Food and Drug Administration (FDA) says eating two ounces of black licorice per day for at least two weeks could prompt an irregular heart rhythm, called an arrhythmia, in adults 40 and older.

So is black licorice bad for you? When consumed in high amounts, glycyrrhizin, a sweet compound found in licorice root, causes potassium levels to temporarily drop, which in turn may cause abnormal heart rhythms, high blood pressure, swelling, lethargy and, in extreme cases, even heart failure. These issues normally go away once consumption stops.

Though the FDA’s new black licorice warning is attracting attention, doctors have had concerns about the confection for a while. Back in 2012, for example, a group of researchers from Chicago’s Mercy Hospital and Medical Center published a review in Endocrinology and Metabolism meant to serve as “a warning message that should be transmitted from physicians to patients to avoid excessive licorice intake as well as a message to the FDA to start regulating the use of this substance.”

For fans of black licorice, the FDA recommends eating it in moderation, and contacting a doctor immediately if you experience irregular heart rhythms or muscle weakness after indulging. Licorice also may interact poorly with certain drugs such as aspirin, oral contraceptives and herbal supplements, so if you’re taking any medications, you may want to speak with a doctor before digging in.

Even if you never eat black licorice, it’s good to be aware of its health implications, as licorice root is often used as a flavoring and sweetening agent in soft drinks, teas and other consumer products. Conversely, a lot of black licorice candy sold in the U.S. uses little or no authentic licorice, instead relying on similar-tasting anise oil.

Just scan the ingredients before you indulge, and keep portion sizes in check.

A man in Canada “overdosed” on licorice by drinking too much licorice tea, which caused his blood pressure to soar to dangerous levels, according to a new report of the case.

The 84-year-old man went to the emergency room (ER) after he took his blood pressure at home and noticed very high readings. He was also experiencing headache, sensitivity to light, chest pain and fatigue, along with swelling in his calves, according to the report, published today (May 27) in the Canadian Medical Association Journal.

At the ER, the man’s systolic blood pressure (the “top” number on a blood pressure reading) was nearly 200 mm Hg. Normal blood pressure is 120/80 mm Hg. Doctors consider any blood pressure measurement above 180 for systolic blood pressure (or above 120 for diastolic blood pressure, the “bottom” number on a reading) to be a hypertensive crisis that requires immediate medical care.

Doctors at McGill University in Montreal treated the man with several medications to lower his high blood pressure, and his symptoms improved over the next 24 hours.

Later, the man told doctors that he had been drinking one to two glasses of homemade licorice tea a day for the last two weeks. This type of tea is made from the roots of the licorice plant, Glycyrrhiza glabra. It is a popular drink in Egypt, where it is known as “erk sous,” the authors wrote in the study.

Consuming too much licorice root or candies flavored with licorice root — including black licorice — is known to be toxic, according to the U.S. Food and Drug Administration (FDA).

That’s because licorice root and black licorice contain a compound called glycyrrhizin, which can cause the body’s potassium levels to fall. This, in turn, can lead to health effects such as high blood pressure, abnormal heart rhythms and swelling, the FDA says.

The FDA regulates how much glycyrrhizin is allowed in food, but still recommends that people avoid eating large amounts of licorice at any one time. (Of note, many “licorice” or “licorice flavored” products manufactured in the U.S. do not actually contain any licorice, but instead are flavored with anise oil, which has the same smell and taste, according to the FDA.)

In the current case, the man knew about the link between licorice and high blood pressure, but he didn’t think he was consuming too much licorice, the report said.

The case highlights an opportunity for doctors “to educate their patients with hypertension about the potential adverse effects of licorice to prevent licorice-related complications,” the authors conclude.

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Originally published on Live Science.

When it comes to candy preferences, black licorice might be just as divisive as candy corn.

But on the eve of Halloween, the Food and Drug Administration (FDA) has struck terror in the hearts of black licorice eaters of a certain age by posting a formal warning about the chewy candy.

On Monday, the FDA issued a consumer update advising candy eaters who are 40 years of age or older to limit their gorging of black licorice to a maximum of two ounces (about three 1-inch pieces) a day — or risk hospitalization from an irregular heart rhythm or arrhythmia.

Trending stories,celebrity news and all the best of TODAY. Too much black licorice won’t just turn your teeth black. It might be bad for your heart, too. Getty Images Stock

The agency’s experts determined that the candy contains enough of the sweetening compound glycyrrhizin — derived from the licorice root — to significantly lower the body’s potassium levels.

The effects in the parents who pilfer their children’s trick-or-treat hauls can be anything but sweet — including abnormal heart rhythms, elevated blood pressure levels, edema and even congestive heart failure, in extreme cases.

Hidden Halloween dangers: How to keep your family safe when trick-or-treating

Oct. 27, 201703:48

Several studies in medical journals have also found that, regardless of age, people with a history of heart disease or high blood pressure are particularly susceptible to the effects of glycyrrhizin when ingested.

So those at a greater risk should eat these delicious slime-filled spider treats in moderation, for example.

Or if you just have to eat something chewy and sweet, munch down on this simple dessert delicacy of Twinkie hotdogs, that use a little bit of red licorice as a literal and figurative garnish.

There is good news, however. Usually after black licorice is consumed, potassium levels go back to normal and there tend to be no lasting health effects once the person stops eating it.

Regardless of age, the FDA has issued the following guidelines when it comes to eating licorice:

  • No matter what your age, don’t eat large amounts of black licorice at one time.
  • If you have been eating a lot of black licorice and have an irregular heart rhythm or muscle weakness, stop eating it immediately and contact your healthcare provider.
  • Black licorice can interact with some medications, herbs and dietary supplements. Consult a health care professional if you have questions about possible interactions with a drug or supplement you take.


Licorice is a common flavoring agent and food product. When used as a food product, licorice is not likely to produce health benefits or side effects. When used as a medicinal product, licorice may produce both desired and unwanted effects on the body.

Licorice has been used in alternative medicine as a possibly effective aid in treating heartburn when combined with other plants or extracts in a specific preparation. Licorice may also be possibly effective in treating symptoms of eczema (itching, swelling, redness) when applied to the skin.

Other uses not proven with research have included treating psoriasis, canker sores, irritable bowel syndrome, high cholesterol, muscle cramps, cancer pain, arthritis, bleeding, stomach ulcers, and many other conditions.

It is not certain whether licorice is effective in treating any medical condition. Medicinal use of this product has not been approved by the FDA. Licorice should not be used in place of medication prescribed for you by your doctor.

Licorice is often sold as an herbal supplement. There are no regulated manufacturing standards in place for many herbal compounds and some marketed supplements have been found to be contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.

Licorice may also be used for purposes not listed in this product guide.

Follow all directions on the product label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

You should not use this product if you are allergic to licorice, or if you have:

  • low levels of potassium in your blood (hypokalemia);
  • past or present cancer of the breast, ovary, or uterus; or
  • a history of endometriosis or uterine fibroids.

Ask a doctor, pharmacist, or other healthcare provider if it is safe for you to use this product if you have:

  • kidney disease;
  • heart disease;
  • high blood pressure;
  • a nerve-muscle disorder;
  • erectile dysfunction; or
  • if you eat a lot of salty foods.

The use of licorice as a flavoring agent or food product is likely to be safe during pregnancy. However, taking large amounts of licorice during pregnancy may increase your risk of miscarriage or premature labor. Do not use this product if you are pregnant.

It is not known whether licorice passes into breast milk or if it could harm a nursing baby. Do not use this product if you are breast-feeding a baby.

Do not give any herbal/health supplement to a child without medical advice.

Generic Name: licorice (LIH koe rish)
Brand Name:

Medically reviewed by on Oct 14, 2019 – Written by Cerner Multum

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Important Information

Follow all directions on the product label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use this product if you are allergic to licorice, or if you have:

  • low levels of potassium in your blood (hypokalemia);

  • past or present cancer of the breast, ovary, or uterus; or

  • a history of endometriosis or uterine fibroids.

Ask a doctor, pharmacist, or other healthcare provider if it is safe for you to use this product if you have:

  • kidney disease;

  • heart disease;

  • high blood pressure;

  • a nerve-muscle disorder;

  • erectile dysfunction; or

  • if you eat a lot of salty foods.

The use of licorice as a flavoring agent or food product is likely to be safe during pregnancy. However, taking large amounts of licorice during pregnancy may increase your risk of miscarriage or premature labor. Do not use this product if you are pregnant.

It is not known whether licorice passes into breast milk or if it could harm a nursing baby. Do not use this product if you are breast-feeding a baby.

Do not give any herbal/health supplement to a child without medical advice.

How should I take licorice?

When considering the use of herbal supplements, seek the advice of your doctor. You may also consider consulting a practitioner who is trained in the use of herbal/health supplements.

If you choose to use licorice, use it as directed on the package or as directed by your doctor, pharmacist, or other healthcare provider. Do not use more of this product than is recommended on the label.

Do not use different forms (powder, root, extract, liquid, teas, etc) of licorice at the same time without medical advice. Using different formulations together increases the risk of an overdose.

Do not take topical (for the skin) licorice by mouth. Topical forms of this product are for use only on the skin.

If you need surgery, stop taking licorice at least 2 weeks ahead of time.

Call your doctor if the condition you are treating with licorice does not improve, or if it gets worse while using this product.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra licorice to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking licorice?

Grapefruit and grapefruit juice may interact with licorice and lead to unwanted side effects. Discuss the use of grapefruit products with your doctor.

Avoid using chewing tobacco that is flavored with licorice. This product could raise your blood pressure or cause serious side effects.

Avoid taking licorice with other herbal/health supplements that can affect your heart. This includes digitalis, lily-of-the-valley, pheasant’s eye, and squill.

Also avoid taking licorice with herbal/health supplements that can have laxative effects. This includes aloe vera (taken by mouth), buckthorn, cascara sagrada, castor oil, rhubarb, and senna.

Licorice side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Although not all side effects are known, licorice is thought to be possibly safe when taken for a short period of time (no longer than 4 weeks).

Long-term use of licorice may cause serious side effects. Stop using this product and call your healthcare provider at once if you have:

  • weakness, loss of movement in any part of the body;

  • high blood pressure–severe headache, blurred vision, pounding in your neck or ears, nosebleed, anxiety, shortness of breath;

  • low potassium–confusion, uneven heart rate, extreme thirst, increased urination, leg discomfort, muscle weakness or limp feeling; or

  • signs of a brain disorder–confusion, memory problems, hallucinations, unusual thoughts or behavior, decreased alertness, or loss of consciousness.

Common side effects may include:

  • headache, tired feeling;

  • missed menstrual periods;

  • fluid retention (swelling, rapid weight gain); or

  • sexual problems in men (loss of interest, impotence, trouble having an orgasm).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect licorice?

Do not take licorice without medical advice if you are using a medication to treat any of the following conditions:

  • any type of infection (including HIV, malaria, or tuberculosis);

  • anxiety or depression;

  • arthritis pain, occasional pain, or tension headaches;

  • asthma or allergies;

  • birth control pills or hormone replacement therapy

  • cancer;

  • erectile dysfunction;

  • heartburn or gastroesophageal reflux disease (GERD);

  • high blood pressure, high cholesterol, or a heart condition;

  • migraine headaches;

  • psoriasis, rheumatoid arthritis, or other autoimmune disorders;

  • a psychiatric disorder; or

  • seizures.

Do not take licorice without medical advice if you are using any of the following medications:

This list is not complete. Other drugs may interact with licorice, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this product guide.

Further information

  • Consult with a licensed healthcare professional before using any herbal/health supplement. Whether you are treated by a medical doctor or a practitioner trained in the use of natural medicines/supplements, make sure all your healthcare providers know about all of your medical conditions and treatments.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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Licorice is mostly associated with candy and has been used in food and medicine for 1,000 years. It contains various compounds that may help with heartburn, cancer, and a leaky gut. Keep reading to learn more about its health benefits.

What Is Licorice Root?

Licorice, or liquorice, is a plant native to southern Europe and Asia and used to flavor candies, sweeteners, and tobacco products. It is also a widely-used Chinese herb .

Licorice has many components with promising health benefits. It has been used in herbal and folk medicine for its anti-inflammatory properties.

Deglycyrrhizinated Licorice (DGL) vs Regular Licorice

Glycyrrhizin is an active compound in licorice with several health benefits, as well as significant side effects like hypertension .

Deglycyrrhizinated licorice (DGL) has glycyrrhizin removed, thus preventing its side effects. DGL is available in wafers, capsules, liquids, and lozenges .

Without glycyrrhizin, DGL is not associated with any identified adverse effects but still retains some of its beneficial properties. DGL supplements lack the side effects of glycyrrhizin and glycyrrhizic acid . DGL is typically used to treat stomach ulcers and other digestive problems.

Active Compounds


The main active component of licorice is glycyrrhizin, which is transformed into glycyrrhizic acid in the gut. Glycyrrhetinic acid is a potent inhibitor of an enzyme (11-ß-HSD) that turns cortisol to a less active form (cortisone) – so, glycyrrhizic acid in regular licorice increases cortisol levels .

The liver breaks down glycyrrhetinic acid, but taking too much licorice might lead to toxic glycyrrhetinic acid buildup .


Glabridin is the most abundant flavonoid in licorice. Preliminary research suggests it is antioxidant, anti-inflammatory, and neuroprotective. This flavonoid is absorbed well in humans, though more studies are needed. .

Licochalcone A

Licochalcone A (LicoA) is a polyphenol. It has potential antiparasitic, antibacterial and anti-cancer properties .

It stops inflammation in cells by suppressing the lipopolysaccharide (LPS) signaling, COX-2, and UV light-induced damage. It may also prevent cancer (by suppressing the Akt/mTOR pathways) .


Isoliquiritigenin has potential antioxidant, anti-inflammatory, and antitumor effects. It has a high affinity for the liver, kidneys, and small and large intestines .

It is absorbed well in rats but has a bioavailability of 12%, likely because the liver and gut break most of it down .


Glabrene is an isoflavonoid in licorice root extract. It binds to estrogen receptors and activates estrogen-regulated genes .

Glabrene can mimic estrogen , suggesting that it might slow down bone loss and cardiovascular decline in menopausal women. However, additional clinical studies need to determine whether glabrene is safe and effective.


Coumarins are compounds that have a sweet smell. The main coumarin in licorice is called glycycoumarin and it’s absorbed well in animals .

Other Compounds

Health Benefits of Licorice Root

1) Lowering Inflammation

In an analysis of 93 clinical, animal, and cell-based studies, licorice extract was observed to have anti-inflammatory activities .

Licorice extract promoted regulatory T cells in mice, suggesting that licorice can protect against autoimmune and inflammatory diseases .

Lipopolysaccharide (LPS) activity, TNF-α production, and NF-kB activity all lead to inflammation in the brain. Treatment with dehydroglyasperin C (a licorice flavonoid) stops the pro-inflammatory activity in the brain and helps prevent neuron cell death .

Ethanol extract of licorice also reduced alcohol-induced liver injury in mice by reducing key liver inflammation markers .

You may use licorice for your inflammatory issues if your doctor determines that it may help in your case.

2) Gut Inflammation & Ulcers

Licorice was a good adjunctive treatment to standard clarithromycin triple therapy in the treatment of Helicobacter pylori in a clinical trial on 120 people. It increased the eradication rate of H. pylori by about 20% .

In another trial on 50 people with dyspepsia, licorice helped symptoms of nausea, indigestion, and stomach pains .

In rats with stomach ulcers caused by aspirin, licorice decreased the number and size of the ulcers .

The evidence is limited but suggests that licorice may help with dyspepsia and ulcers.

3) Menopausal Symptoms

In a clinical trial on 60 menopausal women, licorice was more effective than hormone replacement therapy (HRT) at reducing hot flash duration, but had no effect on hot flash severity. In another trial on over 200 women, an herbal extract formula with liquiritigenin helped with menopausal hot flashes .

Glabridin, liquiritigenin, and glabrene have estrogen-like activities, which may help women who have low estrogen levels, such as in the case of menopause .

Glabridin had a similar effect on human cell culture to estradiol-17beta (the most potent form of estrogen). Glabrene bound to estrogen receptors and also stimulated muscle cell formation in cell-based studies .

1) Reducing Heart Disease Risk

In a clinical trial on almost 100 people with high cholesterol, a year of deglycyrrhizinated licorice (DGL) consumption decreased total cholesterol, LDL cholesterol, and blood pressure levels .

In a mouse model of heart attack, the anti-inflammatory and anti-oxidative effects of licorice helped mitigate damage to the heart tissue and also facilitate faster recovery .

The available evidence is insufficient to support the role of DGL in reducing the risk of heart disease. More clinical trials are needed.

In addition, regular licorice that contains glycyrrhizin and glycyrrhizic acid can cause the body to excrete more potassium and increase blood pressure, which may ultimately worsen heart conditions .

2) Polycystic Ovarian Syndrome (PCOS)

In a clinical trial on 32 women with PCOS, glycyrrhetinic acid reduced testosterone levels while inducing regular ovulation. Two other licorice metabolites (glabridin and glabrene) have estrogen-like effects that may also help treat PCOS .

These preliminary finding needs to be validated in larger, more robust clinical studies.

3) Fatigue

Licorice increased cortisol levels and activity by inhibiting 11-beta-HSD (the enzyme that converts cortisol to the less active cortisone) and SULT2A1 (the enzyme that tags steroid hormones, including cortisol, for elimination) in 20 healthy volunteers. The increase in cortisol may help with energy levels. In addition, it also increases DHEA and testosterone levels .

Glabridin, a polyphenolic flavonoid from licorice extract, reduced exercise-induced fatigue in mice. Mice treated with glabridin swam for a longer period of time compared to control mice. The larger the dose of glabridin, the longer the mice could swim. Mice treated with glabridin also had lower markers of fatigue, such as blood lactic acid levels and blood nitrogen urea, and higher glycogen levels .

A single clinical trial and a study in mice cannot be considered sufficient evidence to claim that licorice reduces fatigue. Further clinical research is needed.

Animal and Cell Research (Lack of Evidence)

No clinical evidence supports the use of licorice for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed should not be interpreted as supportive of any health benefit.

Weight Loss

In mice and rats, licorice flavonoid oil helps weight loss by enhancing fat oxidation during light exercise .

Licorice root powder was also effective in reducing body weight gain and fat deposition in mice .

Brain Protection

Glabridin, a major flavonoid of Glycyrrhiza glabra (licorice), may help protect the brain from stroke-related injuries. In stroke-induced rats, glabridin injection (at 25mg/kg) significantly decreased brain damage, prevented nerve cell death, and lowered DNA damage. It also increased antioxidant levels in the brain .

Licorice flavonoids may also prevent oxidative damage in the brain. Its antioxidant effects help decrease seizure-induced brain cell death in mice .

Diabetes can cause memory and learning problems. In diabetic mice, glabridin extract from licorice helped preserve cognitive function .

Oral glabridin administration at 25 and 50 mg/kg reversed learning and memory deficits in diabetic rats. Additionally, it helped improve brain function in non-diabetic rats .

Inflammation in the brain can lead to many diseases like Alzheimer’s, dementia, and multiple sclerosis. Stopping pro-inflammatory activities could help protect the brain .

Treatment with dehydroglyasperin C (a licorice flavonoid) prevented LPS (a bacterial toxin) from inducing TNF-α production in a cell-based study. It also reduced NF-kB activity, which may help stop neuron cell death and inflammation .

Sleep Quality

The GABA receptor is an important target for inducing sleep. Gabrol and liquiritigenin from licorice root extract induced sleep in mice via the GABA receptor. This decreased the time required to fall asleep and increased the length of non-REM sleep without decreasing deep sleep .

Male Infertility

In mice, licorice extract increased sperm production, which may benefit male infertility .


Components of licorice were effective against several hallmarks of cancer, including cell proliferation, inflammation, cell death resistance, and making its own blood vessels in cell-based studies.

However, many substances have anti-cancer effects in cells, including downright toxic chemicals like bleach. This doesn’t mean that they have any medical value. On the contrary, most substances (natural or synthetic) that are researched in cancer cells fail to pass further animal studies or clinical trials due to a lack of safety or efficacy.

In an oral cancer cell line, a polysaccharide from licorice promoted apoptosis and prevented cancer cells from growing. Licorice was specifically toxic to human cancer cells, but not healthy cells .

Licochalcone A and liquiritigenin block inflammatory and proliferative pathways in cells .

Licochalcone A also inhibited cancer cells from generating its own blood vessels (angiogenesis) by blocking the VEGF receptor .

Licorice flavonoids prevented colitis-associated cancer and reduced tumor formation in mice .

“Bad” estrogens can cause cancer. Liquiritigenin may act as a “good” estrogen and prevent cancer by binding to estrogen receptor beta .


Preliminary research suggests that licorice stimulates the immune system and has antioxidant properties. Its active compounds also had antiviral, antibacterial, and anti-fungal properties in test tubes .

In a cell-based study, glycyrrhizic acid (from licorice extract) was effective in controlling the growth of bacteria . Alcoholic licorice root extract inhibited two types of bacteria in cell culture (S. mutans and L. acidophilus). These two types of bacteria can damage teeth .

Note, however, that these are very preliminary results that haven’t been validated in humans or even in animals. Further research is needed to determine if licorice may help fight the infections caused by these microorganisms.

Side Effects & Precautions

Deglycyrrhizinated Licorice (DGL)

Chronic or excessive consumption of regular licorice can cause unwanted complications and health problems. Since these side effects mostly come from glycyrrhizic acid, using DGL can help avoid these side effects, except when the desired benefit is directly associated with glycyrrhizic acid itself .

Regular Licorice

1) May Increase Cortisol

In large doses, licorice can increase cortisol levels.

Cortisol is a steroid hormone and is also known as the “stress hormone.” It can increase or decrease blood pressure, glucose levels, immune responses, etc. in response to stress .

Glycyrrhizic acid and glycyrrhetinic acid, active metabolites (products of metabolism) of licorice extract, act like aldosterone. They inhibit the 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) enzyme and stop it from converting cortisol to cortisone. This causes an increase in cortisol half-life and an increase in cortisol activity .

The hypothalamic–pituitary–adrenal (HPA) axis is an important response system to stress. Normal cortisol levels help maintain the HPA axis. However, excess cortisol can cause HPA axis dysfunction and lead to chronic stress, depression, alcoholism, and other disorders .

2) May Cause High Blood Pressure

A longer half-life of cortisol means that it takes longer for the concentration of cortisol in the blood to decrease. Excess cortisol can contribute to high blood pressure. A study found that these effects of glycyrrhizic acid were greater in women than in men .

The increase in cortisol locally in the adrenals can increase mineralocorticoids, which can increase blood pressure. Among non-hypertensive people, the increase in blood pressure (3.1 – 14.4 mgHg) is dependent on the amount of licorice consumed .

The increase in cortisol can also cause pseudo-hyperaldosteronism. This condition is characterized by elevated blood pressure, decreased blood potassium concentration, and the retention of water and sodium .

3) May Slow Down Drug Metabolism

Multiple components of licorice, including liquiritigenin and isoliquiritigenin, inhibit the CYP3A4 gene and cytochrome P450 enzymes. Inactivation of P450 enzymes could also slow down drug metabolism, enhance their concentration in the blood, and increase the risk of drug side effects .

4) May Lower Potassium Levels

When licorice metabolites inhibit the 11-βHSD2 enzyme, it also causes excess mineralocorticoid production and a decrease in potassium levels. In multiple case studies, excessive licorice consumption caused hypokalemia (low potassium) and muscle weakness .

Licorice-induced hypokalemia can lead to arrhythmia (irregular heartbeat) and cause heart problems .

Still, this effect seems to vary among patients. The full effect of licorice on potassium depends on the person’s health, the medication they are taking, and other factors according to an observational study on 360 people .

Glycyrrhetic acid can also bind to mineralocorticoid receptors, but its affinity is less than that of aldosterone .

5) May Cause Problems During Pregnancy

In a survey of over 100 Finnish women who gave birth to premature babies, heavy licorice consumption was significantly associated with shorter pregnancy terms. The glycyrrhizic acid from licorice increases cortisol levels, which may cause an increase in prostaglandin levels in the uterus. This may trigger contractions .

The inactivation of 11β-HSD2 by licorice can cause HPA axis dysfunction. In a study on over 300 pregnant women, those who consumed high amounts of licorice had lower placental 11β-HSD2 levels. Their children tended to have behavioral problems associated with HPA axis dysfunction .

However, these effects were investigated in cohort studies. These types of studies can associate factors with certain health conditions but not establish them as their cause. Other genetic and environmental factors may have contributed to the effects observed.

6) Other Rare Side Effects

Licorice consumption may reduce testosterone levels in healthy men. However, these results are mixed between studies. More tests need to be done before any definite conclusions are reached .

Some rare side effects include heart attack and stroke, but few studies have shown these results .

Drug Interactions

Some compounds in licorice can interact with drugs. To help avoid interactions, be sure to tell your doctor about all medications, vitamins, or herbs you’re taking to find out how licorice might interact with something else you are taking.

Glabridin, for example, inhibits cytochromes 3A4 and 2B6 – P450 enzymes that help metabolize drugs. This means that it could affect how your prescription drugs work.

Licorice Root Supplements

Both licorice root and DGL are available as supplements. The FDA doesn’t approve them for any conditions due to the lack of solid clinical research. Regulations set manufacturing standards for supplements but don’t guarantee that they’re safe or effective. Speak with your doctor before supplementing

DGL is safer and may be a better choice for most people.

What are the benefits of licorice root?

There are more than 300 different compounds in licorice, some of which have antiviral and antimicrobial properties.

Some clinical studies investigating the potential benefits of licorice have had promising results, particularly in the following areas:

Skin inflammation and infection

Share on PinterestLicorice root may help treat eczema.

Eczema is the term for a group of skin conditions that, according to the National Eczema Association, affect over 30 million people in the United States.

Eczema can cause itching, redness, scaling, and inflammation.

Glycyrrhiza glabra extract, or licorice root extract, may be effective against bacteria that can infect the skin, according to a study in the Iranian Journal of Pharmaceutical Research.

The study showed antimicrobial activity against Staphylococcus aureus, which can cause skin infections, such as impetigo, cellulitis, and folliculitis. In this study, the researchers used extracts from the leaves and roots of the plant.

Stomach discomfort and ulcers

A double-blind study found that an extract containing glabridin and glabrene, which are flavonoids present in licorice root, was effective in relieving stomach discomfort. The extract reduced nausea, stomach pain, and heartburn.

Infection with bacteria called Helicobacter pylori can cause peptic ulcers in some people. Research suggests that a licorice extract may help kill H. Pylori bacteria. A clinical trial of 120 people found that the addition of licorice extract to the standard treatment significantly improved H. Pylori eradication.

Hepatitis C

Glycyrrhizin may help treat hepatitis C, a virus that infects the liver. Without treatment, hepatitis C can cause inflammation and long-term liver damage. Researchers have reported that glycyrrhizin demonstrates antimicrobial activity against hepatitis C in cell samples and may hold promise as a future treatment for this virus.

Doctors in Japan use an injectable form of glycyrrhizin to treat people who have chronic hepatitis C that does not respond to other treatments. The results of laboratory studies in Japan suggest that it may be helpful for this.

Tooth decay

Some research suggests that licorice may help kill bacteria in the mouth that cause tooth decay.

However, although licorice has demonstrated antibacterial activity in the laboratory setting, human studies have not yet proven that it has any cavity-fighting power. Its ability to inhibit the growth of oral bacteria means that it does have potential as a future cavity treatment though.

Sore throat

Many people think of licorice as a sore throat remedy. A small study recruited people who were having a breathing tube inserted into their windpipe before surgery. Following its removal, the breathing tube can cause a postoperative sore throat, known as POST.

The researchers showed that gargling a licorice solution for 1–15 minutes before surgery was as effective as a ketamine gargle in reducing the incidence and severity of POST.

Another similar study found that solutions with a higher concentration of licorice were more effective than less concentrated solutions in improving POST.

Research shows black licorice has little-known negative health effects

Dr. Stan Van Uum, a professor in the divisions of Clinical Pharmacology and Endocrinology and Metabolism at Western, warns that binge eating black licorice can send your blood pressure soaring, as well as cause dramatically lower levels of potassium in the body, resulting in abnormal heart rhythms and even paralysis. Credit: Paul Mayne // Western News

Black licorice. You either love it – or you hate it. But one Western researcher is offering a reason to pass the next time you think about reaching for that black licorice jelly bean, twist or whip – your health.

Dr. Stan Van Uum, a professor in the divisions of Clinical Pharmacology and Endocrinology and Metabolism, warns that binge eating the popular confectionary can send your blood pressure soaring, as well as cause dramatically lower levels of potassium in the body, resulting in abnormal heart rhythms and even paralysis.

The problems are compounded, he continued, because most Canadian physicians don’t know to ask about it.

Hypertension (high blood pressure) is one of the most common problems encountered in the primary-care setting. Numerous secondary causes of hypertension exist and most are potentially reversible. The ability to screen and manage such causes may spare patients from prolonged medical therapy and complications.

Van Uum cited the case of a sweet-toothed 51-year-old patient who recently presented himself in the emergency room with complaints of abdominal pain for three days, plus a day of decreased appetite, vomiting and diarrhea. His elevated blood pressure and hypokalemia (low potassium) led doctors to run a series of tests.

Upon further questioning, doctors discovered the patient had recently started eating large amounts of black licorice jelly beans – about 50 a day – which he continued to eat while in hospital.

That was all the information doctors needed.

The diagnosis? Licorice-induced hypertension.

“Most people wouldn’t think about it. Patients wouldn’t think of mentioning it. They don’t see it as an issue,” Van Uum said of the case study he recently co-authored in the journal Postgraduate Medicine. “If the physician doesn’t ask about it, you may not find out. We thought it was a good reason to try to bring the issue back to people’s memory that, in certain cases, there could be underlying causes, and by asking the right questions you can make major changes.”

Glycyrrhetinic acid – the active ingredient in licorice – is the root cause of the problem, through its effects on the body’s cortisol metabolism, taking away a protective mechanism, Van Uum explained. Licorice causes your body to retain water and salt, therefore lowering potassium levels. An enzyme in the body acts as a gatekeeper, with the cortisol on one side and a receptor on the other, not allowing the cortisol to get through because it’s continuously inactivated. But licorice stops that inactivation, allowing the cortisol to pass through.

So, how often would doctors see a case such as this? It depends on what country you’re in.

“In the Netherlands, it’s the second or third question the doctor would ask if a patient is showing signs of high blood pressure. It’s very common and familiar to them,” Van Uum said of the popular Dutch candy. “Same goes for some other Scandinavian countries, as well.

“In Canada, people are not well aware of it. Therefore, it requires a sort of refresher because there can be reasons you don’t really think of.”

Much of the black licorice sold in the United States, however, isn’t dangerous at all as it does not contain actual licorice. Instead, manufacturers add anise to the candy to give it a licorice-like flavor.

In a similar case, another patient saw his blood pressure soar in January and February, then drop back to normal by March. It happened again the following year. His doctors’ inquiry discovered the patient was receiving an annual Christmas package filled with, you guessed it, black licorice treats.

“It’s again something that, if you are not aware of, you don’t find out,” said Van Uum, who knows of a patient in the Netherlands whose licorice consumption led to temporary paralysis.

That said, Van Uum stressed you don’t need to cut out the tasty treats together.

“Whatever you do, take it with measure and don’t binge on it. It’s about moderation.”

The effects on the body depend on the amount of licorice eaten and the patient’s sensitivity to the ingredient. There are also products – such as chewing tobacco, smoking cessation aids, teas and even cheeses – that contain licorice, so it is important for physicians to ask for, and patients to share, detailed dietary histories in the workup of hypertension.

Patients may not be aware or properly informed of the potential side effects of licorice and are unlikely to list it among their medication, Van Uum noted.

“If you find someone who has a certain increase in blood pressure, and a relatively young person, because blood pressure goes up with age, if its severity is more than you expect, you need blood tests to further check,” he said. “With high blood pressure, there are always underlying causes. But if you can find them, you can either adjust the treatment or take it away, and the patient may not even need medication at all.”

Had the licorice diagnosis not been made with the 51-year-old patient, he would have likely gone on a number of medications to treat his symptoms, which themselves could have had potential side effects. And the jelly bean binging likely would have continued.

“Physicians need to take a moment and think about the causes, rather than just treating the consequences in general,” Van Uum said. “If you deal with the causes, it’s always better. Reflect for a moment if something has changed. Most family doctors will not see this, therefore, if you don’t ask, you don’t find out.”

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The dangers of overconsumption of licorice Provided by University of Western Ontario Citation: Research shows black licorice has little-known negative health effects (2017, April 21) retrieved 2 February 2020 from This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

The Scary Reason You Might Want to Avoid This Halloween Candy

Additional reporting by Meghan De Maria.

The sweet stuff in your kids’ trick-or-treat buckets may come with a bitter side effect. When eaten in large quantities, black licorice can cause serious health issues. This Halloween, you’ll want to stay vigilant about the candy, whether you’re looking out for your kids or just indulging your own sweet tooth.

“Consumed occasionally and in moderation, it’s unlikely you would experience any detrimental effects from black licorice,” explains GP clinical lead Dr. Daniel Atkinson at, a U.K.-based healthcare service. “But if you were to eat too much black licorice over a sustained period of time—more than 50 grams a day for two weeks straight, for example—then you are risking your health for a number of reasons.”

Why is black licorice so dangerous?

It all has to do with glycyrrhizin, licorice root’s sweet compound. “Glycyrrhizin decreases potassium levels and increases sodium levels in the blood,” Dr. Atkinson explains. And while you’d have to eat a good amount of licorice to get to that point, it could have some scary side effects.

A drop in potassium levels could lead to an abnormal heart rhythm in addition to heart failure, high blood pressure, edema, and lethargy, according to the FDA.

“Potassium plays an important role in the body. It helps us better transmit nerve signals, aids normal muscle function, plays a role in the balance of fluids, and has a number of other functions, too,” says Dr. Atkinson. “The term for low potassium levels is hypokalemia. This can lead to heart palpitations, irregular heartbeat, weakened muscle function, or even high blood pressure.”

How much black licorice is too much?

While 50 grams, or two ounces, might sound like a lot of candy, it’s not actually that difficult an amount to reach, especially if you’re a licorice lover.

“This isn’t actually as much as it sounds,” Dr. Atkinson says. “A serving of 8-10 small pieces is probably between 40 and 50 grams.”

Are certain people more at risk for the health risks black licorice poses?

Adults over 40 and parents of young children will want to be especially careful of how much licorice they and their children are eating.

“Children have a smaller body surface area, which predisposes them to a higher risk than adults,” explains Dr. Raj Singh, a Nevada-based nephrologist. The FDA also warns that several medical studies have linked licorice consumption with health problems in adults over 40.

In fact, a review in the journal Therapeutic Advances in Endocrinology and Metabolism found that overconsumption of this polarizing candy is linked to high blood pressure and hypokalemic myopathy, or low-potassium-level–related metabolic muscle weakness.

“Individuals with high blood pressure, especially those taking diuretics or water pills such as HCTZ (hydrochlorothiazide), are at the most risk, as these medications force the kidneys to waste potassium in the urine, which can cause severe hypokalemia (low levels of potassium in the blood),” Dr. Singh explains. “Individuals with atrial fibrillation (a common cardiac arrhythmia) are at high risk as even minor fluctuation in blood potassium levels can trigger a fatal arrhythmia.” If you have those particular conditions, you might want to check with your doctor about how much black licorice is safe in your case.

RELATED: No-sugar-added recipes you’ll actually look forward to eating.

How can you prevent black licorice’s adverse effects?

Make sure to stay below the FDA’s recommended limit of two ounces a day. And it never hurts to beef up your diet with some potassium-rich foods to make sure your body’s potassium stores aren’t depleted.

“Theoretically, consuming a diet high in potassium (bananas) or drinking potassium-rich fluids such as coconut water, orange juice, Gatorade, or Powerade can protect against the potassium-lowering effects of black licorice and stabilize the cardiac membrane,” says Dr. Singh.

And if you do end up experiencing any licorice-induced symptoms, contact your doctor right away. Halloween candy is a fun treat, but this is one variety you’ll want to be wary of.

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Endocrine Abstracts

A 59-year-old lady with headaches and malaise was found to be hypertensive with a blood pressure (BP) 210/105. An MRI brain revealed a haemorrhagic lesion in the right temporal lobe. There were no other signs of end organ damage. Her medications included atenolol 25 mg OD, ramipril 10 mg OD and bendroflumethiazide 2.5 mg OD. It transpired that she has been drinking 5 cups of liquorice tea per day over the last 18 months. Following a vomiting illness she stopped liquorice tea consumption. Her BP normalised and antihypertensive medications were weaned off.

Liquorice consumption is an unusual but well-reported cause of secondary hypertension. Excessive consumption of liquorice can cause hypertension and hypokalaemia, which may lead to cardiac arrhythmias and myopathy. The pathogenesis involves the action of glycyrrhetinic acid (GA), the active metabolite of liquorice, on the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). GA inhibits the action of 11β-HSD2 resulting in a mineralocorticoid excess state causing hypertension hypokalaemia, alkalosis, sodium and water retention, and suppression of renin–aldosterone system.

The lowest observed dose resulting in adverse effects is 100 mg of GA daily. Hence, using a safety factor of 10, a daily intake of 10 mg GA per person is regarded as an acceptable safe dose. This means no more than 10–30 mg liquorice, i.e. no more than half a cup of liquorice tea per day.

This case demonstrates a rare cause of hypertension and highlights the importance of taking a detailed history to avoid unnecessary investigations and treatment.

Can I drink Pukka teas that have licorice in if I have high blood pressure?

We love licorice at Pukka. Sweetness is just one of the six essential tastes that our Herbsmith Sebastian Pole considers when creating our blends, carefully balancing the therapeutic effect of our teas with the best taste experience. It is calming and nourishing, and its silky nature helps soothe your whole system. In many traditional medicine approaches around the world it is also seen as a good harmoniser of other herbs in a mix. Adding licorice to our teas brings out the best of all ingredients so you get the most balanced blend.

Some studies into the effects of licorice on our bodies have suggested that it has the potential to increase blood pressure and decrease blood potassium levels. These studies have used either isolated extracts of a constituent known as glycyrrhizin (GL) or licorice candy sweets, and the implications for taking licorice in its natural form, e.g. in teas, have not been established. For example, in licorice candy, high levels of sugar and salt may also affect blood pressure or potassium levels. Studies on the risks of licorice candy have also been done in countries where recreational consumption is more common.

Most Pukka teas have levels of licorice that are too low to have an impact on blood pressure unless taken excessively. However, there are a few where levels are higher and here we should take due precautions. If you have moderate or severe hypertension (high blood pressure) you should monitor your readings if you are taking regular daily quantities of Pukka teas that have high levels of licorice. The teas with the most have the word ‘Licorice’ in the title of the tea: Three Licorice, Peppermint and Licorice, and Licorice and Cinnamon (for which we put a high blood pressure warning on the labels). Other relatively high licorice levels are seen in Mint Refresh and Lemon, Ginger and Manuka.

On balance it is probably wise not to consume any high-licorice tea every day if you have high blood pressure. However, it is regularity and frequency that makes the difference and you should be able to enjoy occasional cups of all these teas safely.

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