Should I take naltrexone in the morning or at night?


When and how much Low Dose Naltrexone LDN (dosage and what time evening or morning?)

Dosage and when to take LDN by Dr. Bihari

According to the Low Dose Naltrexone Homepage, which was created by former colleagues of the late Dr. Bihari, the best time to take LDN is between 9 pm and 3 am.

You will see below that this has become a hotly discussed subject
(and as usual) eventually a consensus may be reached.
This is Dr. Bihari’s explanation of why evening dosing
is preferable:
“The reason the hour is important is that 90% of the
endorphins are made in the middle of the night, between 2
and 4 in the morning. If a small dose of naltrexone is taken
in the late evening, generally at bedtime, generally
endorphin production is boosted as much as threefold, 300%.
The naltrexone itself is gone in about 3 hours, but the
endorphins remain elevated all the next day. So the
naltrexone doesn’t significantly block the endorphins
but does cause them to rise.”
To test the hypothesis that evening dosing is preferable to
daytime dosing, Dr. Skip Lenz, a Florida pharmacist with
many years’ experience dispensing LDN and counseling
people taking it, compared the results of two studies, both
of which involved LDN in the treatment of progressive forms
of MS. One study used morning dosing (because participants
complained of sleep issues), and the other used evening
dosing. Based on his comparison, he concluded that morning
dosing was a poor substitute for evening dosing.


I found this useful thread on the LDN forum talking about AM and PM dosing: ”In regard to daytime dosing, of all the clinical trials of LDN conducted with humans, only one used daytime dosing–a German study with a group of MS patients. While about a third of the group did experience limited benefit, this is the comment made about the trial by Dr. David Gluck. Unfortunately, because of some early complaints of sleep disturbance, the principal investigator of this trial switched all of the study group to taking LDN at 9 am in the morning, a questionable dosage time. It is generally recognized that the most effective time to take LDN is at bedtime, between 9 pm and 3 am, due to the fact that the endorphins for each day are always produced at their peak rate in the pre-dawn hours. A 9 am dosage time, as was used in this trial, might conceivably suppress—rather than boost—a patient’s immune system.
Low Dose Naltrexone (LDN): The German MS Study

And also note that this study was not conducted to see if LDN would halt any disease progression of any type of MS, the study was way too short for that, 10days. I think it was basically to look at symptom improvement on only 3mg LDN”.
Here is a comment on the day/night LDN dosing by a very credible LDN Pharmacist, Skip Lenz…please read the entire comment as the two cycles he mentions pack different punch levels.
”I really hate to get involved with this question, and the he said,he said
responses. Who is right, Zagon or Bihari, well they both are right. One has to look at the diurnal nature of endorphin secretion to understand HOW they are both right. You get your zenith peak during your normal sleep cycle. You get your penultimate peak during your wake cycle. Taking LDN prior to your zenith peak will give you more bang for your buck than prior to your wake cycle peak.
Therefore you will get some increase taking LDN at times other than prior to bedtime but they will not be the most you can get. Now if you take it indiscriminately temporally, then depending of which peak is next in the cycle, you will get a fraction of the response you would get if taken at an appropriate time frame. This explains why both docs are right, for those taking it in the am, you get the PM peak to skew upwards, those taking the PM dose gets the am peak to skew upwards”.


“Links to LDN forums discussing AM or PM dosing.”

LDN-day/night dosing controversy/research

Mechanisms involved in beneficial effect of LDN

Changing time zones and LDN timing

Why I do Bihari dosing protocol over Zagon/Gilhooly

Taking LDN AM instead of PM ????

LDN Taken Morning or Night?
People who take LDN in the morning for allergies or depression can take the risk,
but people who use it for cancer, MS and other serious diseases should be careful
not miss the full potential of LDN and follow the Bihari protocol of evening dosing.


Dosage (Amounts) of LDN to be taken.

A lot of discussion has gone in to dosage, and how much
to take for your issue, and sensetivity to medication.

We never even suggest a dosage, we are not doctors, but this is
my experience as a user since 2009 and a supplier since 2012.

Also one must remember that Naltrexone has been deemed non-toxic, and was approved
by the FDA many years ago, in much higher dosages. 4.5mg is only about 5%
of the usual amount prescribed. We take almost a homeopathic dose one could say.

Dr Bihari says in his video (that is highly respected), that he found no effect below 1mg and little effect above 4.5mg.
I have read on forums that some people are very sensitive to medications, so they start at 0.05mg and build up to
say 3mg per day. For Hep C the blanket dosage they put all people
on was 4.5mg per day, taken at 9pm at night.
If people suffer insomnia from the LDN as some do (almost
the only side effect reportred) it is suggested they drop
the dose to say 2mg to 3mg per night, and if it still persists,
taking it in the day time.

Although 4.5mg per night has worked very well for me, after 5 years I have lowered my dosage to 3mg
per day, as that seems to be the perfect average dose for most people.
Here is some very good information and advice in regard
to LDN dosage …

Side Effects and Dosing of Low Dose Naltrexone (LDN)
By Dudley Delany, R.N., M.A., D.C.


With regards to insomnia a neurologist Dr Turel was interviewed this year about LDN. He touches on the subject of why some people wake up after taking LDN at night and find it difficult to go back to sleep. He prescribes LDN to be taken in the morning as a result. Here’s a link to the interview if you’re interested
— Jayne C


Anothder View

There are also a LOT of people on this forum who follow a morning dosing protocol because we have found that it works better for us than evening dosing does. When I first started taking LDN in the evening, I did not derive ANY benefits with taking LDN at night. Once I switched to morning dosing, I had numerous health benefits occur within the first week of starting morning dosing of LDN. Yes, I understand that initially Dr. Bihari’s recommendation was to take LDN in the evening however, I think that we have seen with the numerous people on this site that have had success with morning dosing that it cannot be dismissed! That doesn’t mean I am not going to tell people that they shouldn’t try evening dosing but if that doesn’t work for them then I will tell them to try morning dosing rather than have them quit LDN all together.
As we all know, the optimal dosage for a person varies and it is the same thing as to what TIME people take their LDN. Some people will find their optimal time is in the evening and some people like me will find that morning dosing is preferable. People respond differently to LDN and need to find what works best for them- both in dosage AND in timing of LDN. It is a shame that this argument continues because it doesn’t have to- just agree to disagree. We all know that people take LDN at different times of the day and find success with those times thus proving that taking LDN at different times works for different people. Why disagree about something that has already been proven by numerous people on this forum? I’m pretty sure you’re not going to talk any morning dosers out of their morning dosing time when clearly it works for them just as nobody will talk an evening doser out of taking LDN in the evening when it is working fine for them.
The most important thing here is that we need to help people find their optimal dosage and timing of their LDN. We have been lucky enough to find success with LDN, now I think we owe it to others to share our experience with LDN and help guide them to the best health that they can possibly get (or that we can help them get). I personally would like to start the new year off on a good note and try to work WITH each other and concentrate on how we can help people vs going over issues that aren’t as relevant anymore.
Stay warm everybody and have a good day!


A question about timing of taking LDN

There is no evidence that night time works any better either. You just have to look at the number of posts in various FB groups and on this forum from PEOPLE who cannot tolerate night time dosing due to lack of sleep and therefore benefit from taking it in the morning.
We cannot dismiss or ignore these patients and even worse, make people feel like second class citizens because they cannot tolerate taking LDN at night. That is unprofessional and just wrong. LDN does not work to a clock as has been suggested when LDN first started being prescribed.
There’s been so much ‘promoting’ about LDN based on a ‘boosting immune system and endorphin’ theory that it’s difficult for some who have built up a business on this theory to accept otherwise, even when the science stares at them in the face. For some reason we were all told that endorphins peak between 2-4am. If you can show me a published study proving this I would welcome it. But here’s one study with humans showing endorphins peak at 8.25am and OGF (the magic behind LDN) at 5pm.

I agree with you, we have to be careful how we interpret a study and therefore wouldn’t you agree it’s best to share facts and links to studies that have been published in peer review journals rather than a misguided opinion? The German study switched to morning dosing because patients could no longer tolerate lack of sleep but it was a short study and has never been published (just someone’s “interpretation” of it).
If people still want to believe that LDN works best taken at night because of an endorphin boost between 2-4am when there’s no published studies supporting that, that’s fine. But think about this – if you believe taking LDN between 9pm – 2am which time is correct as taking it at 9pm means you have likely cleared your receptors by 1am, but taking it at 2am means your receptors are blocked till roughly 6am. It just doesn’t add up when you give a little bit of thought to it.
And yes I agree, LDN won’t work if not taken right. And this includes losing sleep because of taking it at night.. So I am saying take it when it suits you and for some that’s at 8am, others mid-day, some take it at 6pm, others 10pm – whatever!
— Jayne C ( )


Thank you, Brenda, for confirming what I have heard from others on different LDN forums who switched from nighttime to daytime dosing. Usually, when people can’t tolerate evening dosing, it’s because their dose is too high. Lowering the dose generally solves that problem. I am not saying that daytime dosing doesn’t work for some people, but I would first give evening dosing every chance before making the switch. For more information about dosing, visit


Feb 2015

All of the studies except one used night dosing. According to the Low Dose Naltrexone Homepage, which was created by former colleagues of the late Dr. Bihari, the best time to take LDN is between 9 pm and 3 am.
This is Dr. Bihari’s explanation of why evening dosing is preferable:
“The reason the hour is important is that 90% of the endorphins are made in the middle of the night, between 2 and 4 in the morning. If a small dose of naltrexone is taken in the late evening, generally at bedtime, generally endorphin production is boosted as much as threefold, 300%. The naltrexone itself is gone in about 3 hours, but the endorphins remain elevated all the next day. So the naltrexone doesn’t significantly block the endorphins but does cause them to rise.”
To test the hypothesis that evening dosing is preferable to daytime dosing, Dr. Skip Lenz, a Florida pharmacist with many years’ experience dispensing LDN and counseling people taking it, compared the results of two studies, both of which involved LDN in the treatment of progressive forms of MS. One study used morning dosing (because participants complained of sleep issues), and the other used evening dosing. Based on his comparison, he concluded that morning dosing was a poor substitute for evening dosing.
I personally know of people who have switched from night to daytime dosing and have regressed.
If you are still having sleep issues at this point in time, I suggest reducing your dose to 3 mg.
For more information about LDN dosing, including an indepth discussion of evening vs daytime dosing, visit
— Dudley Delany

Naltrexone for Alcohol Dependence: Is This Medication Right For You?

Karen struggled with alcohol for the past six years, but things have gotten much worse as of late. Her program of meetings, yoga, meditation, and reading about recovery didn’t seem to be enough; she was frustrated by her chronic relapses.

“I thought that medication was for the addict at rock bottom,” Karen told me. “After struggling for years, I decided to give it a try.”

Enter Naltrexone

Karen’s doctor wrote her a prescription for naltrexone. He also explained she’d need to spend five to seven days alcohol-free before beginning the medication regimen.

The night before she started naltrexone, Karen bought a bottle of wine and drank most of it. The next several days passed…slowly, but they passed. On the fifth day, she took the first of her prescribed pills.

Naltrexone is an opioid antagonist, meaning that it blocks the effects of opioids. However, it is also commonly used as an anti-craving medication for those who wish to abstain from alcohol entirely. Additionally, the medication can be used to extinguish cravings while a person is still drinking – a method known as the Sinclair Method (TSM), developed by the late David Sinclair. In these instances, a drinker takes one naltrexone pill an hour before drinking, but does not get the buzz he or she normally would. As a result, alcohol cravings are gradually extinguished because there is no real “reward” for drinking.

Angela used naltrexone by the Sinclair Method. “I am down from drinking six or seven nights a week – 70 to 90 units a week – to two or three nights a week and 20 or 30 units. All in six months. You have some amazing phases and not so good ones I have found. The drug works. The hardest thing is overcoming why you drink. You are meant to do TSM with some kind of help, like counseling, and being mindful of how you feel while drinking.”

Naltrexone Use in the United States

While the Sinclair Method is the standard of care for alcohol dependence in Finland, naltrexone is still largely pushed as an anti-craving medication to achieve total abstinence in the U.S. However, some rehabs are now suggesting it for patients as an aid to achieve continued sobriety.

“When I was at rehab, they pushed naltrexone hard,” said Margaret, who went to a well-established rehab at age 39. “They didn’t really give us much of a choice, so I did it. I was so exhausted I could barely get through the family therapy sessions at the end of my 28 days. I went off the medication as soon as I got home.”

Like Margaret, Karen also reported struggling with fatigue while on naltrexone, but to her, it was worth it. “Since I started taking naltrexone, I have a lot of fatigue. I seem to tire easily. However, I had absolutely no cravings for alcohol. None! I was happily surprised that this medication really works!”

Scientific studies are mixed when it comes to the effectiveness of naltrexone for alcohol dependence. A study published in the New England Journal of Medicine examined 627 veterans who took naltrexone daily as an anti-craving medication. They found the veterans who took naltrexone drank just as much at both 13 and 52 weeks as those who took a placebo. A similar opioid antagonist medication, nalmefene, was found to have limited effects in a recent study published in Addiction. “Evidence for the efficacy of nalmefene in reducing alcohol consumption in those with alcohol dependence is, at best, modest, and of uncertain significance to individual patients,” the report states.

However, when taken under the Sinclair method, eight studies in five countries found that naltrexone works. While there were no noticeable effects for patients who took naltrexone while completely abstinent from alcohol, there were noticeable effects for those who took it while still drinking. This appears to be the result of a mechanism called extinction, whereby people stop engaging in a behavior if they no longer get the reward. For example, let’s say you love cheesecake and you eat a slice of it every night, but suddenly your beloved cheesecake stops tasting as good. You’d probably stop craving it, and while you might still have a piece now and then, it would no longer be something you felt you needed every night.

Abstinence vs Moderation

The idea of those with alcohol dependence continuing to drink by the Sinclair Method rubs some people the wrong way in the U.S. We have been conditioned to think that “alcoholics” can never drink again, so seeing them drink can be unsettling. If alcohol dependence is seen as a moral issue or an issue of weakness of willpower, continuing to drink while on naltrexone may not be viewed as “sobriety” by mainstream alcohol treatment. However, for those who either do not wish to be completely abstinent or find that they cannot achieve abstinence, the Sinclair Method could be ideal.

“Drinking is almost required in my profession,” said Kate, a marketing executive with a large international company. She found herself drinking way too much as the stress of her high-powered job increased, yet business dinners, cocktail parties, and office happy hours were not optional in her line of work. “With naltrexone, I can take a sip of a glass of wine, then leave it on the table for an hour. I no longer drink at home, and I no longer feel like I ‘need’ a drink at the end of the day. When I’m taking clients out for dinner, I can drink socially, but not worry about craving so much that I get drunk. This is important to me because when I tried not to drink at all, it raised eyebrows. People wondered if I was an alcoholic. With naltrexone, I can drink normally and no one knows I ever had a problem.”

Using naltrexone by the Sinclair Method also avoids a significant problem with taking it daily: naltrexone blocks opioid receptors, so it not only blocks the effects of alcohol and opioids like heroin, it also blocks pain medication. That means if you were on daily naltrexone and got into a car accident, opioid pain medication would not work.

“They didn’t warn us in rehab that naltrexone would keep pain medication from working,” said Margaret. “I only found out after I left and researched it myself. That’s part of the reason why I went off it. I don’t take any opioid pain meds now, but if something happened to me, I’d want them to work!”

Karen, however, is willing to take the chance. She’s been so thrilled with the anti-craving effects of daily naltrexone that she’s gotten authorization from her insurance company to get the once a month injection version, Vivitrol. “I didn’t think my insurance would cover the expensive alternative Vivitrol injection – it’s $1700 – but I received notification that it had been approved. I would have a $100 co-pay, but I was additionally approved for co-pay assistance, so my co-pay is also covered. I pay $0! This past Tuesday, I received my second injection of Vivitrol. I am still amazed…no cravings at all for alcohol.”

Different people have different goals, but naltrexone is a medication that should be offered to those struggling with alcohol problems in addition to the programs they use to deal with underlying issues behind their drinking. With full knowledge of both the benefits and the risks, those with alcohol dependence can make an informed decision about this medication and whether or not it’s right for them.

Images Courtesy of iStock


Before taking naltrexone,

  • tell your doctor and pharmacist if you are allergic to naltrexone naloxone, other opioid medications, or any other medications.
  • tell your doctor if you are taking any opioid (narcotic) medications or street drugs including levomethadyl acetate (LAAM, ORLAAM) (not available in the US), or methadone (Dolophine, Methadose); and certain medications for diarrhea, cough, or pain. Also tell your doctor if you have taken any of these medications in the past 7 to 10 days. Ask your doctor if you are not sure if a medication you have taken is an opioid. Your doctor may order certain tests to see if you have taken any opioid medications or used any opioid street drugs during the past 7 to 10 days. Your doctor will tell you not to take naltrexone if you have taken or used opioids in the past 7 to 10 days.
  • do not take any opioid medications or use opioid street drugs during your treatment with naltrexone. Naltrexone blocks the effects of opioid medications and opioid street drugs. You may not feel the effects of these substances if you take or use them at low or normal doses. If you take or use higher doses of opioid medications or drugs during your treatment with naltrexone, it may cause serious injury, coma (long-lasting unconscious state), or death.
  • you should know that if you took opioid medications before your treatment with naltrexone, you may be more sensitive to the effects of these medications after you finish your treatment. After you finish your treatment, tell any doctor who may prescribe medications for you that you were previously treated with naltrexone.
  • tell your doctor what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention disulfiram (Antabuse) and thioridazine. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had depression or kidney disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking naltrexone, call your doctor.
  • if you need medical treatment or surgery, including dental surgery, tell the doctor or dentist that you are taking naltrexone. Wear or carry medical identification so that healthcare providers who treat you in an emergency will know that you are taking naltrexone.
  • you should know that people who overuse drugs or alcohol often become depressed and sometimes try to harm or kill themselves. Receiving naltrexone does not decrease the risk that you will try to harm yourself. You or your family should call the doctor right away if you experience symptoms of depression such as feelings of sadness, anxiousness, hopelessness, guilt, worthlessness, or helplessness, or thinking about harming or killing yourself or planning or trying to do so. Be sure that your family knows which symptoms may be serious so they can call the doctor right away if you are unable to seek treatment on your own.



The following clinically significant adverse reactions are described elsewhere in the labeling:

  • Accidental Opioid Overdose
  • Injections Site Reactions
  • Precipitated Opioid Withdrawal
  • Hepatotoxicity
  • Depression and Suicidality
  • Eosinophilic Pneumonia
  • Hypersensitivity Reactions

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

In all controlled and uncontrolled trials during the premarketing development of VIVITROL, more than 1100 patients with alcohol and/or opioid dependence have been treated with VIVITROL. Approximately 700 patients have been treated for 6 months or more, and more than 400 for 1 year or longer.

Adverse Events Leading To Discontinuation Of Treatment

Alcohol Dependence

In controlled trials of 6 months or less in alcohol-dependent patients, 9% of alcohol-dependent patients treated with VIVITROL discontinued treatment due to an adverse event, as compared to 7% of the alcohol-dependent patients treated with placebo. Adverse events in the VIVITROL 380 mg group that led to more dropouts than in the placebo-treated group were injection site reactions (3%), nausea (2%), pregnancy (1%), headache (1%), and suicide-related events (0.3%). In the placebo group, 1% of patients withdrew due to injection site reactions, and 0% of patients withdrew due to the other adverse events.

Opioid Dependence

In a controlled trial of 6 months, 2% of opioid-dependent patients treated with VIVITROL discontinued treatment due to an adverse event, as compared to 2% of the opioid-dependent patients treated with placebo.

Common Adverse Reactions

Table 1 lists all treatment-emergent clinical adverse reactions, regardless of causality, occurring in ≥ of patients with alcohol dependence, for which the incidence was greater in the combined VIVITROL group than in the placebo group. A majority of patients treated with VIVITROL in clinical studies had adverse reactions with a maximum intensity of “mild” or “moderate”.

Table 1: Treatment-emergent Adverse Reactions (Reactions in ≥% of patients with alcohol dependence treated with VIVITROL and occurring more frequently in the combined VIVITROL group than in the placebo group)

Body System Adverse Reaction /
Preferred Term
Placebo Naltrexone for extended-release injectable suspension
N=214 400 mg
380 mg
190 mg
N % N % N % N % N %
Gastrointestinal Disorders Nausea 24 11 8 32 68 33 53 25 129 29
Vomiting NOS 12 6 3 12 28 14 22 10 53 12
Diarrheaa) 21 10 3 12 27 13 27 13 57 13
Abdominal painb) 17 8 4 16 23 11 23 11 50 11
Dry Mouth 9 4 6 24 10 5 8 4 24 5
Infections & Infestations Pharyngitisc) 23 11 0 0 22 11 35 17 57 13
Psychiatric Disorders Insomnia, sleep disorder 25 12 2 8 29 14 27 13 58 13
Anxietyd) 17 8 2 8 24 12 16 8 42 10
Depression 9 4 0 0 17 8 7 3 24 5
General Disorders & Administration Site Conditions Any ISR 106 50 22 88 142 69 121 58 285 65
Injection site tenderness 83 39 18 72 92 45 89 42 199 45
Injection site induration 18 8 7 28 71 35 52 25 130 30
Injection site pain 16 7 0 0 34 17 22 10 56 13
Other ISR (primarily nodules, swelling) 8 4 8 32 30 15 16 8 54 12
Injection site pruritus 0 0 0 0 21 10 13 6 34 8
Injection site ecchymosis 11 5 0 0 14 7 9 4 23 5
Asthenic conditionse) 26 12 3 12 47 23 40 19 90 20
Musculoskeletal & Connective Tissue Disorders Arthralgia, arthritis, joint stiffness 11 5 1 4 24 12 12 6 37 9
Back pain, back stiffness 10 5 1 4 12 6 14 7 27 6
Muscle crampsf) 3 1 0 0 16 8 5 2 21 5
Skin & Subcutaneous Tissue Disorders Rashg) 8 4 3 12 12 6 10 5 25 6
Nervous System Disorders Headacheh) 39 18 9 36 51 25 34 16 94 21
Dizziness, syncope 9 4 4 16 27 13 27 13 58 13
Somnolence, sedation 2 1 3 12 8 4 9 4 20 5
Metabolism & Nutrition Disorders Anorexia, appetite decreased NOS, appetite disorder NOS 6 3 5 20 30 14 13 6 48 11
a) Includes the preferred terms: diarrhea NOS; frequent bowel movements; gastrointestinal upset; loose stools
b) Includes the preferred terms: abdominal pain NOS; abdominal pain upper; stomach discomfort; abdominal pain lower
c) Includes the preferred terms: nasopharyngitis; pharyngitis streptococcal; pharyngitis NOS
d) Includes the preferred terms: anxiety NEC; anxiety aggravated; agitation; obsessive compulsive disorder; panic attack; nervousness; posttraumatic stress
e) Includes the preferred terms: malaise; fatigue (these two comprise the majority of cases); lethargy; sluggishness
f) Includes the preferred terms: muscle cramps; spasms; tightness; twitching; stiffness; rigidity
g) Includes the preferred terms: rash NOS; rash papular; heat rash
h) Includes the preferred terms: headache NOS; sinus headache; migraine; frequent headaches

In the open-label, long-term safety study conducted in the US, the commonly reported adverse reactions among the opioid-dependent patients in the study were similar to those commonly observed events in the alcohol-dependent populations in VIVITROL clinical trials as displayed in Table 1, above. For example, injection site reactions of all types, nausea and diarrhea occurred in more than 5% of patients on VIVITROL in the open-label study. In contrast, 48% percent, of the opioid-dependent patients had at least one adverse event in the “Infections and Infestations” Body System. Adverse Reactions/Preferred Terms of nasopharyngitis, upper respiratory tract infection, urinary tract infection, and sinusitis were most commonly reported.

In the placebo-controlled study in opioid-dependent patients conducted in Russia, the overall frequency of adverse events was lower than in the U.S. population described above. Table 2 lists treatment-emergent clinical adverse events, regardless of causality, occuring in ≥2% of patients with opioid dependence, for which the incidence was greater in the VIVITROL group than in the placebo group. All adverse events were assessed as having a maximum intensity of “mild” or “moderate.”

Table 2: Treatment-emergent Clinical Adverse Events (Events in ≥2% of patients with opioid dependence treated with VIVITROL and occurring more frequently in the VIVITROL group than in the placebo group)

Body System Adverse Event /
Preferred Term
n % n %
Investigations Alanine aminotransferase increased 7 6 16 13
Aspartate aminotransferase increased 3 2 13 10
Gamma-glutamyltransferase increased 4 3 9 7
Infections and Infestations Nasopharyngitis 3 2 9 7
Influenza 5 4 6 5
Psychiatric Disorders Insomnia 1 1 8 6
Vascular Disorders Hypertension 4 3 6 5
General Disorders and Administration Site Conditions Injection site pain 1 1 6 5
Gastrointestinal Disorders Toothache 2 2 5 4
Nervous System Disorders Headache 3 2 4 3

Laboratory Tests

Eosinophil Count

In clinical trials, subjects on VIVITROL had increases in eosinophil counts relative to subjects on placebo. With continued use of VIVITROL, eosinophil counts returned to normal over a period of several months.

Platelet Count

VIVITROL 380 mg was associated with a decrease in platelet count. In clinical trials, alcoholdependent patients treated with VIVITROL experienced a mean maximal decrease in platelet count of 17.8 × 103/μL, compared to 2.6 × 103/μL in placebo patients.

After 24 weeks of treatment, opioid-dependent patients treated with VIVITROL experienced a mean maximal decrease in platelet count of 62.8 × 103/μL, compared to 39.9 × 103/μL in placebo patients. In randomized controlled trials, VIVITROL was not associated with an increase in bleeding-related adverse events.

Hepatic Enzyme Elevations

In short-term, controlled trials, in alcohol-dependent patients, the incidence of AST elevations associated with VIVITROL treatment was similar to that observed with oral naltrexone treatment (1.5% each) and slightly higher than observed with placebo treatment (0.9%).

In the 6-month controlled trial conducted in opioid-dependent subjects, 89% had a baseline diagnosis of hepatitis C infection, and 41% had a baseline diagnosis of HIV infection. There were frequently observed elevated liver enzyme levels (ALT, AST, and GGT); these were more commonly reported as adverse events in the VIVITROL 380 mg group than in the placebo group. Patients could not enroll in this trial if they had a baseline ALT or AST value that was more than three times the upper limit of normal. More patients treated with VIVITROL in this study experienced treatment-emergent elevations in transaminases to more than three times the upper limit of normal than patients treated with placebo. Shifts to more than three times the upper limit of normal occurred in 20% of patients treated with VIVITROL as compared with 13% of placebo patients. Shifts in values of AST to more than three times the upper limit were also more common in the VIVITROL (14%) arm compared with the placebo (11%) arm. Opioiddependent patients treated with VIVITROL experienced a mean maximal increase from baseline ALT levels of 61 IU/L compared with 48 IU/L in placebo patients. Similarly for AST, opioiddependent patients treated with VIVITROL experienced a mean maximal increase from baseline AST levels of 40 IU/L compared with 31 IU/L in placebo patients.

Creatinine Phosphokinase

In short-term controlled trials in alcohol-dependent patients, more patients treated with VIVITROL 380 mg (11%) and oral naltrexone (17%) shifted from normal creatinine phosphokinase (CPK) levels before treatment to abnormal CPK levels at the end of the trials, compared to placebo patients (8%). In open-label trials, 16% of patients dosed for more than 6 months had increases in CPK. For both the oral naltrexone and VIVITROL 380 mg groups, CPK abnormalities were most frequently in the range of 1–2 × ULN. However, there were reports of CPK abnormalities as high as 4x ULN for the oral naltrexone group, and 35 × ULN for the VIVITROL 380 mg group. Overall, there were no differences between the placebo and naltrexone (oral or injectable) groups with respect to the proportions of patients with a CPK value at least three times the upper limit of normal. No factors other than naltrexone exposure were associated with the CPK elevations.

More opioid-dependent patients treated with VIVITROL 380 mg (39%) shifted from normal creatinine phosphokinase (CPK) levels before treatment to abnormal CPK levels during the study as compared to patients treated with placebo (32%). There were reports of CPK abnormalities as high as 41.8 × ULN for the placebo group, and 22.1 × ULN for the VIVITROL 380 mg group.

Other Events Observed During The Vivitrol Clinical Studies

The following is a list of treatment-emergent adverse reactions reported by alcohol- and/or opioid-dependent subjects treated with VIVITROL in all clinical trials. The listing does not include those events already listed in the previous tables or elsewhere in labeling, those events for which a drug cause was remote, those events that were so general as to be uninformative, and those events reported only once that did not have a substantial probability of being acutely lifethreatening.

Blood and Lymphatic System Disorders – lymphadenopathy (including cervical adenitis), white blood cell count increased

Cardiac Disorders – angina pectoris, angina unstable, atrial fibrillation, cardiac failure congestive, coronary artery atherosclerosis, myocardial infarction, palpitations

Eye Disorders – conjunctivitis, vision blurred

Gastrointestinal Disorders – abdominal discomfort, colitis, constipation, flatulence, gastroesophageal reflux disease, gastrointestinal hemorrhage, hemorrhoids, pancreatitis acute, paralytic ileus, perirectal abscess

General Disorders and Administration Site Conditions – chest pain, chest tightness, chills, face edema, irritability, lethargy, pyrexia, rigors

Hepatobiliary Disorders – cholecystitis acute, cholelithiasis

Immune System Disorders – seasonal allergy, hypersensitivity reaction (including angioneurotic edema and urticaria)

Infections and Infestations – bronchitis, gastroenteritis, laryngitis, pneumonia, sinusitis, tooth abscess, upper respiratory tract infection, urinary tract infection, advanced HIV disease in HIVinfected patients

Investigations – weight decreased, weight increased

Metabolism and Nutrition Disorders – appetite increased, dehydration, heat exhaustion, hypercholesterolemia

Musculoskeletal and Connective Tissue Disorders – joint stiffness, muscle spasms, myalgia, pain in limb

Nervous System Disorders – cerebral arterial aneurysm, convulsions, disturbance in attention, dysgeusia, mental impairment, migraine, ischemic stroke, paresthesia

Pregnancy, Puerperium, and Perinatal Conditions – abortion missed

Psychiatric Disorders – abnormal dreams, agitation, alcohol withdrawal syndrome, euphoric mood, delirium, libido decreased

Respiratory, Thoracic, and Mediastinal Disorders – chronic obstructive pulmonary disease, dyspnea, pharyngolaryngeal pain, sinus congestion

Skin and Subcutaneous Tissue Disorders – night sweats, pruritus, sweating increased

Vascular Disorders – deep venous thrombosis, hot flushes, pulmonary embolism

Postmarketing Experience

Hypersensitivity Reactions Including Anaphylaxis

Hypersensitivity reactions including anaphylaxis have been reported during postmarketing surveillance.

Reports From Other Intramuscular Drug Products Containing Polylactide-Co-Glycolide (PLG) Microspheres

Retinal Artery Occlusion

Retinal artery occlusion after injection with another drug product containing polylactide-coglycolide (PLG) microspheres has been reported very rarely during postmarketing surveillance. This event has been reported in the presence of abnormal arteriovenous anastomosis. No cases of retinal artery occlusion have been reported during VIVITROL clinical trials or postmarketing surveillance. VIVITROL should be administered by intramuscular (IM) injection into the gluteal muscle, and care must be taken to avoid inadvertent injection into a blood vessel .

Read the entire FDA prescribing information for Vivitrol (Naltrexone XR Inj)

Jay hello my name is norbert machan im 34 years old and if one good thing i can say is ive been clean of opiates since Sept 18 2016 I’m proud but there is no other way I’m sorry about your husband .. yes u are right but can i tell u from experience um i started at 23 no pills straight H heroin started snorting in the first year IV use i died on 3 different twice because i didn’t know my sleeping meds don’t work together even thou it was over 12 hours later plus a non narcotic pills have half lives and once because i was to clean and i decided to do a Twenty $20 or 0.1 of a gram. you know being clean and thinking ur body can do the usual NO..
I tried every way u can think of to mange my heroin addiction but even if i had millions of dollars guess what i know it wouldnt be enough i would either OD or go to prison done both i been to the methadone clinic getting i think the max was 120 unless u did some extra shit so u could get up to 150 like some kind of physical with there doctors at the clinic once a day 7 times a week $75 every week.. okay cool but the one thing is in a whole year every time i had to take a drop – drug test i couldn’t pass so after a year they came to me an said mr machan we cant have you here anymore because of my results so what they did was they let me come still but day by day they were decreasing my dosage so 120 Monday 119Tuesday 118 Wednsday and so on till i decided to get some heroin to substitute for the methadone it all leveled out i was back on heroin living but really dead because all i did with my life was always looking for my next fix or how i was going to get it i never done any sexual favors but caused a lot of trouble and a lot of heart pain for friends and family and always feeling like i wasn’t a human i was a SHIT BAG so the methadone clinic went like this my mother made sure to get me there every mourning by like 600 then by like 10-11 close to noon i would do a shot of heroin because the methadone would fade out not the well feeling but the mental high so iv would do a shot but it would have to be like double of what i usually did so like a Fifty $50 or a 0.3 now this mix the methadone and heroin it would give me pins and needles some people love it i hate it i like to taste it after i injected it u can tell a lot by the taste about ur product then by 3-4 in the afternoon I’m down the street smoking crack tweaking and guess what to come down 7-8-9 o’clock another shot of heroin then all over again so I’m still struggle of yeah forgot i don’t even got insurance no job not even Obama care nothing damn so i start going to rehab joints (free ones) and then boom i get prescribed suboxone ” praise the lord ” thinking to myself i wont be sick anymore yeah sounds good but I’m only taking them when i don’t got heroin then when i do take the suboxone I’m only taking little slivers of it so i wont be sick so if i do end up getting some heroin i will still feel the shot or the effects of the heroin plus LOL back then this is what I’m thinking i get 90 of these suboxone stripes a month and back then u or i could of sold each strip for $20 so why take the strip when i can get a bag of heroin that is when people were buying them so really still struggling and then not to mention if u were to cold turkey Methadone hum your body will go into withdraws in like 2days from your last dose but the sickness that comes with it is way worse then the heroin withdraw and can last all the way up to 30 days a whole month really what do u think the odds of an addict not doing something that they know is going to make um feel a whole 360 “hell to heaven” and this is in seconds very very hard now 30 days okay now suboxone if ur taking um as prescribed and stop ull start getting sick about a day later after your last dose but withdraws can stick around for 14 more days and stronger effects of withdraw then the heroin withdraw now what do u think an addict “ME” is going to be sick as fuck for 2 weeks naw I’m going to find something before the 14 days are up and not to mention that in these withdraws ur shitting puking and restless legs and worst one of them all CANT SLEEP FOR MORE THAN 20min at a time ull go crazy from just trying to rest but your body wont let u actually its kind of like having a bad FLU but even worse and now the heroin ull be sick anywhere from 10 hours to 24 hours from ur last use because its so cut up now that most of the time the people are only doing little %s of actual heroin because of all the different cuts including fentanyl that’s way stronger then heroin it self but the withdraw lasts 3-7 days now 3 days is hard enough i couldn’t do it but after u been down ,out, a piece of shit that wants to change and is really a good person just messed up and now I’m not even a productive member of society people rather look away then help and me trying to get one over on whoever i can for my next fix now methadone suboxone if ur taking them how ur supposed to they are made to make u go into an automatic withdraw called a precipitated withdraw and they are pretty intense or this can happen to if u take a blocker but u haven,t waited for the heroin or opiates to leave ur body basically like trying to rush thru the withdraw sux and if u try to do any opiates after one of these precipitated withdraws sorry wont help ull feel like shit waste of money time u just got to wait it out….. now Vivitrol for me Miracle when i get the shot in my ass check i don’t get any highs it works for a 30 day period LOL not day by day u know they say take it day by day naw i got a new plan on life i can plan out for a whole month now and know I’m safe because I’m an addict but this is my second time around on vivitrol the first time i was on it i would wait for like the 27 -28 -29th day of the month then do some heroin and then i would only get the slight taste and nothing else idk what i was thinking but right now I’ve been clean since Sept 18 2016 and today i can truly say i haven’t touched it nor tried any funny shit because i know i will lose but Jay now to get to ur question sometimes even tho we know whats best for us we don’t change because idk don’t care its to hard uhm fuck it I’m not causing anybody any problems shit i do what i wanna no its coming to reality with ur self and saying I’m done I’m tired i had enough i hate this life i hate myself i wanna change its knowing the difference between really wanting to stop and acting on that walk it like u talk it or like me i wasn’t ready to stop i was just trying to do everything else hoping something might work trying to make everyone else around me happy um rehabs and everything else didn’t work what worked was me going to jail and knowing i was done but i have a memory of my mother asking me this. Now this was before jail and i was still heavy in my addictions strung out /junkie she said DUDE wtf have u ever tried asking god for help LOL that’s what i thought then I’m in my cell and i think about what my mom asked me years ago boom it pops in my head and i ask for help one time in my cell but i said it out loud like i meant it i did i said lord please help me i don’t want live life this way anymore ill do whatever just help me please and then in mind i had the picture and this is what it was i said I’m going to sit this time as long as i have to sit and then get back on vivitrol when i get back out and that’s what i did in jail the day before i got i got the shot and been on it ever since I’m off probation i do smoke weed i have an nice paying job and finally living again not searching for my next fix sometimes u just have to wait and wait till the person had enough or they decide that that’s what they want u have to be committed not 99% only 100% and one again sorry about ur husband dang the doctor should of told u guys nothing can flush vivitrol out like suboxone and methadone because u wont get high or actually this is for alcoholics to so u wont get drunk or high and the next thing that it can lead to is death because u keep putting more and more of whatever drug till its to much in ur system like if u wern’t on the vivitrol and basically you overdose because ur body cant tell the effects cuts they are blocked and u keep taking more thinking somethings going to change but no no no idk maybe a better study on what ur going to take idk about na/aa because i don’t go i did a 10 month program in prison “rehab” in prison LOL but worked i was locked up for like 18 months then when i got out i had to do 1 year 4 months probation and complete an oaklawn treatment class called sorry i cant think of it but it was after care 16-32 week class at ur pace iv also finished that my plans are to stay on vivitrol as long as i can this my safety net this keeps me living i wanna live and just always remember THESKYISTHELIMIT i don’t want to be on something that controls my decisions if i have it or if i don’t VIVITROL really life saver

Exploring the Pros and Cons of Vivitrol

What Are the Positives of Vivitrol?

There are many positives to using Vivitrol in recovery, such as its ability to block the effects of opioids and diminish some of the reward of drinking alcohol if a person does relapse. When used by people highly motivated in their treatment, such effects may lessen the chances for relapse, especially in the early stages of recovery.

Additionally, Vivitrol may play a role in preventing cravings that might otherwise lead a person to relapse after the initial opioid detoxification process. Though many people are able to resume their recovery trajectory after a relapse, in some instances, an early relapse can lead to a person giving up the recovery the process altogether.

Studies have indicated that the use of an extended-release naltrexone such as Vivitrol may be comparably effective for the treatment of opioid use disorder as a combination of buprenorphine and naloxone (e.g., Suboxone)—an encouraging finding, especially for people who do not wish to remain on opioid agonist maintenance treatment indefinitely.

A related benefit for those on Vivitrol monotherapy would be there is no risk of withdrawal when discontinuing the drug like they do when opioid agonist maintenance is a factor. Consequently, naltrexone therapy doesn’t require a drug taper when discontinuing either. Because the drug is long-lasting, Vivitrol is a convenient treatment tool for people in recovery. It doesn’t require a person to remember to take a pill each day, nor does it require a person to commute to a clinic or treatment facility numerous times per week.

What Are the Negatives of Vivitrol?

Some individuals who take Vivitrol may experience side effects from the drug. These include:

  • Nausea
  • Depression
  • Dizziness
  • Headache
  • Fatigue
  • Sleepiness
  • Insomnia
  • Anxiety

One study conducted by DuPont Pharma on 570 participants who used Vivitrol for alcoholism revealed that nausea was the most common side effect. In fact, 10 percent of participants experienced nausea. Headaches and depression were the next most common side effects of Vivitrol with 7 percent of participants experiencing headaches and 5-7 percent experiencing depression, as noted by the National Institute on Alcohol Abuse and Alcoholism.

Another potential drawback of naltrexone therapy is that it should only be initiated in people who have already withdrawn from both opioids and alcohol. In the case of some longer-acting opioids, this could take as long as 10 days for the acute withdrawal period to resolve prior to the start of naltrexone treatment.

As Vivitrol is administered via intramuscular injection, it necessitates a slightly invasive procedure, although it only requires re-administration every 4 weeks (in contrast to a daily oral medication regimen). Another consequence of such an extended-release application is that any medical situation that might otherwise benefit from opioid use (post-surgical analgesia, pre-surgical induction, emergent injuries) could present some issues in alternately managing.

Lastly, the prolonged opioid receptor blockade achieved through the use of Vivitrol will be accompanied by a significant lowering of opioid tolerance. As a result, relapse associated overdose risks could be elevated in someone who has recently discontinued naltrexone therapy and should be carefully considered as part of a supervised continuum of care for such individuals.


During two randomized, double-blind placebo-controlled 12-week trials to evaluate the efficacy of REVIA as an adjunctive treatment of alcohol dependence, most patients tolerated REVIA well. In these studies, a total of 93 patients received REVIA at a dose of 50 mg once daily. Five of these patients discontinued REVIA because of nausea. No serious adverse events were reported during these two trials.

While extensive clinical studies evaluating the use of REVIA in detoxified, formerly opioid-dependent individuals failed to identify any single, serious untoward risk of REVIA use, placebo-controlled studies employing up to fivefold higher doses of REVIA (up to 300 mg per day) than that recommended for use in opiate receptor blockade have shown that REVIA causes hepatocellular injury in a substantial proportion of patients exposed at higher doses (see WARNINGS and PRECAUTIONS, Laboratory Tests).

Aside from this finding, and the risk of precipitated opioid withdrawal, available evidence does not incriminate REVIA, used at any dose, as a cause of any other serious adverse reaction for the patient who is “opioid-free.” It is critical to recognize that REVIA can precipitate or exacerbate abstinence signs and symptoms in any individual who is not completely free of exogenous opioids.

Patients with addictive disorders, especially opioid addiction, are at risk for multiple numerous adverse events and abnormal laboratory findings, including liver function abnormalities. Data from both controlled and observational studies suggest that these abnormalities, other than the dose-related hepatotoxicity described above, are not related to the use of REVIA.

Among opioid-free individuals, REVIA administration at the recommended dose has not been associated with a predictable profile of serious adverse or untoward events. However, as mentioned above, among individuals using opioids, REVIA may cause serious withdrawal reactions (see CONTRAINDICATIONS, WARNINGS, DOSAGE AND ADMINISTRATION).

Reported Adverse Events

REVIA has not been shown to cause significant increases in complaints in placebo-controlled trials in patients known to be free of opioids for more than 7 to 10 days. Studies in alcoholic populations and in volunteers in clinical pharmacology studies have suggested that a small fraction of patients may experience an opioid withdrawal-like symptom complex consisting of tearfulness, mild nausea, abdominal cramps, restlessness, bone or joint pain, myalgia, and nasal symptoms. This may represent the unmasking of occult opioid use, or it may represent symptoms attributable to naltrexone. A number of alternative dosing patterns have been recommended to try to reduce the frequency of these complaints.


Depression, suicidal ideation, and suicidal attempts have been reported in all groups when comparing naltrexone, placebo, or controls undergoing treatment for alcoholism.


Naltrexone Placebo
Depression 0 to 15% 0 to 17%
Suicide Attempt/Ideation 0 to 1% 0 to 3%

Although no causal relationship with REVIA is suspected, physicians should be aware that treatment with REVIA does not reduce the risk of suicide in these patients (see PRECAUTIONS).

Opioid Addiction

The following adverse reactions have been reported both at baseline and during the REVIA clinical trials in opioid addiction at an incidence rate of more than 10%:

Difficulty sleeping, anxiety, nervousness, abdominal pain/cramps, nausea and/or vomiting, low energy, joint and muscle pain, and headache.

The incidence was less than 10% for:

Loss of appetite, diarrhea, constipation, increased thirst, increased energy, feeling down, irritability, dizziness, skin rash, delayed ejaculation, decreased potency, and chills.

The following events occurred in less than 1% of subjects:


Nasal congestion, itching, rhinorrhea, sneezing, sore throat, excess mucus or phlegm, sinus trouble, heavy breathing, hoarseness, cough, shortness of breath.


Nose bleeds, phlebitis, edema, increased blood pressure, non-specific ECG changes, palpitations, tachycardia.


Excessive gas, hemorrhoids, diarrhea, ulcer.


Painful shoulders, legs or knees; tremors, twitching.


Increased frequency of, or discomfort during, urination; increased or decreased sexual interest.


Oily skin, pruritus, acne, athlete’s foot, cold sores, alopecia.


Depression, paranoia, fatigue, restlessness, confusion, disorientation, hallucinations, nightmares, bad dreams.

Special senses

Eyes–blurred, burning, light sensitive, swollen, aching, strained; ears–“clogged,” aching, tinnitus.


Increased appetite, weight loss, weight gain, yawning, somnolence, fever, dry mouth, head “pounding,” inguinal pain, swollen glands, “side” pains, cold feet, “hot spells.”

Data collected from postmarketing use of REVIA show that most events usually occur early in the course of drug therapy and are transient. It is not always possible to distinguish these occurrences from those signs and symptoms that may result from a withdrawal syndrome. Events that have been reported include anorexia, asthenia, chest pain, fatigue, headache, hot flushes, malaise, changes in blood pressure, agitation, dizziness, hyperkinesia, nausea, vomiting, tremor, abdominal pain, diarrhea, palpitations, myalgia, anxiety, confusion, euphoria, hallucinations, insomnia, nervousness, somnolence, abnormal thinking, dyspnea, rash, increased sweating, vision abnormalities, and idiopathic thrombocytopenic purpura.

In some individuals the use of opioid antagonists has been associated with a change in baseline levels of some hypothalamic, pituitary, adrenal, or gonadal hormones. The clinical significance of such changes is not fully understood.

Adverse events, including withdrawal symptoms and death, have been reported with the use of REVIA in ultra rapid opiate detoxification programs. The cause of death in these cases is not known (see WARNINGS).

In a placebo controlled study in which REVIA was administered to obese subjects at a dose approximately five-fold that recommended for the blockade of opiate receptors (300 mg per day), 19% (5/26) of REVIA recipients and 0% (0/24) of placebo-treated patients developed elevations of serum transaminases (i.e., peak ALT values ranging from 121 to 532; or 3 to 19 times their baseline values) after three to eight weeks of treatment. The patients involved were generally clinically asymptomatic, and the transaminase levels of all patients on whom follow-up was obtained returned to (or toward) baseline values in a matter of weeks.

Transaminase elevations were also observed in other placebo controlled studies in which exposure to REVIA at doses above the amount recommended for the treatment of alcoholism or opioid blockade consistently produced more numerous and more significant elevations of serum transaminases than did placebo. Transaminase elevations occurred in 3 of 9 patients with Alzheimer’s Disease who received REVIA (at doses up to 300 mg/day) for 5 to 8 weeks in an open clinical trial.

Drug Abuse And Dependence

REVIA is a pure opioid antagonist. It does not lead to physical or psychological dependence. Tolerance to the opioid antagonist effect is not known to occur.

Read the entire FDA prescribing information for Revia (Naltrexone)

Naltrexone For Weight Loss: Does LDN Cause It? How?

Low dose naltrexone for weight loss may be used by patients who are looking to reduce their body mass. Low dose naltrexone can offer weight loss help through various ways for these patients. Furthermore, it is also significant to understand further the link between naltrexone and weight loss, including factors that may cause this side effect and the possible theories behind them.

Note that only a doctor may prescribe Naltrexone for weight loss or any other condition. Do not self-medicate any health condition with this medication to avoid hazardous consequences.

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Table of Contents

  • How Does LDN Cause Weight Loss?
  • Who Should Consider Using LDN For Weight Loss?
  • What Are The Factors Affecting LDN Weight Loss?

Does Low Dose Naltrexone Cause Weight Loss?

Among low dose naltrexone side effects, weight loss is one people can benefit from. Despite naltrexone is primarily used for opiate and alcohol addiction treatment, low dose naltrexone (LDN) shows promise in helping patients to lose extra mass. However, naltrexone for weight loss tends to work more effectively on some patients than others; those patients with damaged metabolisms benefit more from the LDN effect on weight.

The amount of mass one can lose taking the drug varies primarily on the period of use and dosage. There were several studies conducted on this issue, and their results range from 3.75 lbs to 7.5 lbs after 2 months of taking low dose naltrexone for weight loss.

How LDN Causes Weight Loss

Several theories exist as to how low dose naltrexone diet pill works. Considering the FDA-approved use of naltrexone, both alcohol and opioids abuse is linked to an increase in body fat in the short-run. During LDN use, patients tend to reduce body mass. Above, there are several theories on how LDN causes losing weight.

Suppressed Appetite

Some patients experience reduced appetite as a side effect while taking naltrexone, also known by the brand name Vivitrol. Therefore, according to this theory, naltrexone weight loss effect stems from the reduction of food intake because of the reduced appetite. A study found that an increase of naltrexone dosage from 25 mg to 200 mg resulted in a reduction of food intake by 30% in obese men participated in the study.

Reduced Insulin Resistance

Research has proven that naltrexone helps to lower insulin levels by 40%, and the link between insulin levels and obesity is quite straightforward. Insulin resistance is one of the primary causes of increased mass in people, especially in hypothyroid patients. Naltrexone HCl for weight loss works by modulating cellular resistance to insulin.

Energy Boost

As many patients report that the drug increases their energy during the day, the enhanced physical activity is a potential outcome of such impact. As a result, users may burn extra calories losing a few pounds.

Improved Sleep Patterns

Lack of adequate sleep causes inflammation and leads to an increase in the body fat in people according to numerous studies. LDN has been proven to improve sleep quality in patients with sleep apnea, as well as some pain syndromes. In this way, LDN helps to lose weight.

Increase In Growth Hormones

Research has suggested that the medication may increase growth hormones in certain patients. Therefore, low dose naltrexone for weight loss works in these patients because the stimulated growth hormones help not only build and maintain lean muscle mass but also increases the burning of fat.

Increased The Thyroid Hormonal Levels

Naltrexone for weight loss can help increase total triiodothyronine (TT3) levels and improve the conversion of total thyroxine (TT4) to total triiodothyronine (TT3). Furthermore, LDN has been shown to improve the immune system and reduce autoantibodies in some autoimmune condition. These two reasons are why low dose naltrexone is used for Hashimoto’s thyroiditis. Naltrexone helps in weight loss in this case because thyroidal gland destruction combined with autoantibodies results in increased mass in people.

Outcome Of Concomitant Side Effects

Naltrexone use is accompanied by some side effects such as diarrhea, nausea, and vomiting. In these cases, patients find any food not very attractive and are unwilling to enjoying it. If these effects are frequent and severe enough, the loss of the body mass can be observed.

Low Dose Naltrexone For Weight Loss: Who Should Use?

It is recommended that patients taking naltrexone diet pills and LDN find a medical professional to monitor them. Furthermore, they can use it in combination with supplements and other medication for the best results.

The following populations can consider using LDN to burn extra body fat:

  • Patients with hormonal imbalances such as insulin and Leptin resistance
  • Patients with autoimmune and weight gain disorders
  • Patients with hypothyroidism and Hashimoto’s Thyroiditis
  • People with a sleep disorder
  • People with chronic pain problems
  • People with known inflammatory conditions
  • People with slow metabolism rates
  • People with ravenous appetites and an imbalance between energy consumption and appetite

Additionally, there are populations who are more and less likely to experience a reduction of their body mass. Among the most vulnerable are:

  • women
  • binge eaters
  • high-dose users
  • overweight individuals or those with obesity
  • those who maintain an inactive lifestyle and practice unhealthy diet

On the contrary, men, low-dose users, normal fit or underweight people, and non-binge eaters can see no or slight reduction in the body mass.

Naltrexone HCl For Weight Loss: Affecting Factors


The amount of body mass that a patient loses during naltrexone weight loss treatment is directly related to the dosage. A large 100 mg ReVia dosage could be as much as 2 times more effective than a 50 mg dose. Moreover, it is also true that body mass loss occurs within a specific dosage range and diminishes outside that range.

Individual Factors

The amount of body mass a patient loses while taking the drug is also subject to some individual factors such as genetics, body size, exercise, and dietary intake. Body size, including the composition of muscle and the amount of fat, is the first determining factor in this case. The greater the dosage one is taking relative to their body size, the more likely they are to experience low dose naltrexone weight loss. Secondly, individuals with the G allele of the A118G polymorphism of the OPRM1 gene have greater therapeutic benefit from Vivitrol alcohol treatment. Simultaneously, it is suggested that individuals with this polymorphism may benefit more from low dose naltrexone for weight loss as well.

Duration Of Use

The cumulative duration of LDN use may dictate how much body fat someone burns. Patients who have taken low dose naltrexone for weight loss for only two weeks are less likely to notice any considerable changes. However, moderate to long term usage of naltrexone HCl for weight loss is far more likely to yield better results as compared to short-term use. Still, some patients have reported no changes in their body mass even after long term use.

Co-Administered Substances

Patients taking Vivitrol together with other drugs or supplements should be aware that these substances may affect the number of kilograms lost. Naltrexone as a weight-loss drug may be used with supplements, but this should be under the strict supervision of a doctor. On the contrary, drugs such as Zyprexa, which is an antipsychotic, may cause someone’s body mass to increase if used in combination with LDN.

LDN And Weight Loss: What To Remember

Low dose naltrexone is used for weight loss because of its resulting side effect on body mass. However, not all patients stand to benefit from this treatment due to factors such as genetics, diet, body composition, length of use, and other co-administered substances. Furthermore, naltrexone HCl for weight loss can have other general side effects, just like other drugs. Professional help in case of severe symptoms is required. While one can find substance treatment by themselves, there are facilities which can aid as well. For example, drug rehabilitation centers offer full support in terms of physical and mental health.

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Low Dose Naltrexone: Does It Work For Weight Loss and Pain?

If someone gave you a medication that could help you lose weight while treating painful and potentially life-threatening illnesses, would you take it? These are some of the purported benefits of the prescription drug Naltrexone when it is taken in small quantities.

This article offers a comprehensive and objective overview of low dose Naltrexone (LDN) for supporters and skeptics alike. We’ll cover what exactly LDN is, how it works, as well as potential treatments and side effects.

Table of Contents

What is Low Dose Naltrexone?

Low dose Naltrexone is pretty much exactly how it sounds—it is a low dose of the FDA approved drug Naltrexone. In high doses, Naltrexone has been prescribed for decades to treat addiction to substances like opioids and alcohol while reducing symptoms of withdrawal. At this level of 50 to 100 milligrams per dose, Naltrexone blocks the euphoric effects of certain drugs and alcohol to reduce cravings and eliminate the need for harmful substances.

In small doses under ten milligrams, however, Naltrexone has an opposite effect as it increases endorphins to boost the immune system and provide relief from pain and inflation. In fact, research has suggested low dose Naltrexone (LDN) has a great deal of potential for treating a wide variety of ailments.


Taking small amounts of various drugs is certainly not a new concept. Microdosing is a simple concept that involves taking far below the recommended dose for a given substance. In the case of LDN, most doses are between three and four milligrams, which is less than ten percent of the standard serving. At this level, LDN is reported to provide a number of benefits beyond helping those with addition.

Does Low-Dose Naltrexone Work?

LDN works by increasing the body’s natural production of endorphins by briefly blocking their effects on the brain. Essentially, taking LDN signals the brain that the body is not producing, and utilizing, endorphins necessary to balance the immune system and create healthy cells. In response, the body produces more endorphins and increases sensitivity to try and capture and use more.

The effect of low-dose Naltrexone typically lasts a couple of hours, during which the body is creating more endorphins in addition to the ones already available. When the low dose of Naltrexone wears off, a rebound happens where the body begins to use the standard endorphins that were already produced in addition to the excess endorphins created because of the LDN. This can aid in regulating the immune system and cell growth which, theoretically, can treat auto-immune and degenerative diseases.

The Benefits of Low-Dose Naltrexone

LDN claims to treat a surprisingly long list of maladies, with some treatments showing more promise than others. The drug has been both individually praised and harshly criticized.

Crohn’s Disease

Crohn’s disease is an autoimmune inflammatory bowel disease affecting around 780,000 Americans. Several studies have been conducted on LDN and Crohn’s disease, as LDN presumably treats autoimmune ailments. In one study, 89 percent of participants experienced positive outcomes with LDN treatment. Two-thirds of participants even entered remission, but it important to note this study only examined 17 individuals.

Other studies have shown low-dose Naltrexone can reduce symptoms of an active Crohn’s disease better than a placebo, and LDN might lead to a reduction in reliance on other drugs to treat the disease. These studies were also fairly small, with 40 and 256 participants respectively. Overall, the evidence in favor of LDN as a treatment of Crohn’s disease is strong, but not definitive.

Pain and Inflammation

LDN can decrease the pain caused by inflammation by blocking the receptors, also known as the opiate receptors, that feel pain. This makes it a potentially effective treatment for several ailments. This efficacy is similar to opioid but does not have the addictive properties of an opioid. Low-dose Naltrexone works on opiate receptors but is a superior treatment alternative.


Two studies have shown LDN to be effective in treating fibromyalgia, a chronic pain condition that typically does not respond to common anti-inflammatory drugs. Research suggests the drug can reduce pain, fatigue, and stress levels while improving overall mood. LDN likely works as it simultaneous blocks pain receptors and improves immune function and reduces inflammation. However, each study examining LDN used a small sample size (10 women in one, 31 in the other) so further research is needed to confirm this potential benefit.

Rheumatoid Arthritis

A small study of ten patients showed the potential of LDN on diseases that cause inflammation and chronic pain. Each patient treated with LDN reported arthritis relief while medicated and a resurgence of symptoms after stopping LDN treatment. This suggests that even if LDN is effective, it may need to be a lifelong, consistent treatment.

Multiple Sclerosis

Multiple Sclerosis, more commonly known as MS, is another autoimmune disease. MS specifically affects the nervous system and disrupts the flow of information from the brain to the rest of the body. Studies indicate LDN may improve the quality of life of MS patients, but has shown no effect on disease modification.

Helps with CRPS Symptoms

CRPS, or Complex Regional Pain Syndrome, may be treated with the pain-blocking potential of LDN. Again, though, studies are small and this claim is not definitive.

Alzheimer’s and Parkinson’s Disease

Low dose or even larger doses of Naltrexone have been shown to stop the progression of degenerative diseases such as Parkinson’s and Alzheimer’s. It is unlikely treatment can reverse damage already done by these diseases. Additionally, studies supporting these claims have been small and some evidence is largely anecdotal. The potential of LDN to slow these incurable diseases is exciting, but more research needs to be done.


A few studies have reported the benefits of LDN in the treatment of children with autism. One researcher found LDN resulted in improved behavior, increased vocality, and decreased repetitive movements or utterances. Others have shown LDN to improve focus and mood while decreasing hyperactivity in patients.

Post-Traumatic Stress Disorder

11 of 15 PTSD patients reported positive effects of LDN treatment. Most claimed they had a clearer perception of themselves and reality and found increased control.

Decreases Nausea in Trauma Patients

When used in conjunction with morphine, LDN did nothing to decrease the pain of trauma patients. However, it did lower their risk for experiencing nausea.

Help Patients Struggling with Drug Problems

Naltrexone was originally approved and prescribed for treating those with drug addictions. Even in low doses, the medication has been shown to decrease the intensity of withdrawal symptoms and reduce cravings.

Heavy-Drinking Smokers

LDN works similarly in those addicted to drugs, alcohol, and cigarettes—even if an individual has more than one addiction. Studies have demonstrated LDN’s ability to reduce cravings as well as the need to feel the euphoria that may drive someone to drink or smoke.

Effective in Treating HIV/AIDS

LDN claims to treat autoimmune disease, and the HIV/AIDS may be the most well-known in this category. One doctor treated AIDS patients with LDN for seven years and found 85 percent of them had no detectable levels of the virus. Even those who test positive for HIV or AIDS turn to LDN to treat symptoms, as LDN corrects the beta-endorphin deficiency found in most patients.

Fights Cancer

Finally, LDN has been positively associated with treating a variety of types of cancer. The drug works alongside chemotherapy and radiation to reduce tumor size by making growths more susceptible to cancer-killing cells and endorphins while increasing production of these helpful cells. One study reported a 75 percent size reduction in the tumors of over 100 patients, while others who were given grim prognoses are still alive and well.

Low Dose Naltrexone Weight Loss

In addition to treating and curing a number of diseases, LDN claims to be an effective way to lose weight. Studies have offered mixed results, with some participants dropping pounds and others reporting no noticeable results. There are a few ways the prescription drug could aid in weight loss efforts, including:

Reduces Insulin Resistance

Full doses of Naltrexone have been shown to decrease insulin levels as it modulates insulin resistance at the cellular level. Particularly in women with high testosterone or PCOS, Naltrexone may be an effective weight loss aid.

May Increase Growth Hormone

In certain patients, Naltrexone can increase the hormone that helps build muscle mass and burn fat. This hormone decreases as weight is gained, making Naltrexone a potential solution for obese individuals.

Modulates Appetite

Weight loss may seem difficult, but it is really a simple equation of calories in versus calories out. Eating less than you burn in a normal day will result in weight loss while eating more leads to weight gain. Naltrexone potentially works by regulating the signals between your brain and your appetite. Essentially, the prescription helps your brain tell your body to eat only as many calories as you typically burn instead of sending constant hunger signals. Eating less can then lead to weight loss and a healthier metabolic system.

Anti-Inflammatory Agent

Inflammation can cause chronic pain and discomfort, but it can also cause hormonal changes that make it difficult to lose weight. Most studies on LDN and inflammation have examined patients with chronic pain, but the medicine may provide an extra benefit in addition to pain relief as it makes weight loss simpler.

May Help Improve Sleep & Sleeping Patterns

Diet and exercise alone are not always enough to achieve a slim figure. Sleep plays a huge role in weight loss and muscle recovery. Research has shown Naltrexone is effective in regulating sleep patterns of patients with sleep apnea. Anecdotal evidence also suggests LDN can help users fall and stay asleep when taken before bed.

The Low Dose Naltrexone Side Effects

Not many adverse side effects have been linked to use of LDN; however, the drug has also not been tested for long-term safety. The most commonly reported side effect is vivid dreams or nightmares, especially during the first few weeks of use. Some patients also report difficulty sleeping, but this usually subsides in a few days. Taking the drug in the morning seems to eliminate both effects altogether.

Other, less reported side effects include pain, vomiting and/or diarrhea, headache, fatigue, loss of appetite, and changes in mood. The warnings that accompany Naltrexone seem to be inconsequential when the medicine is taken in low doses, and it appears LDN is generally safe for most people.

One thing potential users should be aware of is the way to acquire LDN. Naltrexone is only available as a prescription drug and cannot be purchased over the counter, at drug stores, or through online retailers. In fact, it is illegal to sell the drug to an individual without a prescription. Talking with your doctor is the best way to determine if Naltrexone, in any dose size, can be an effective treatment for you. You can also discuss potential side effects, risks, and benefits with your physician before asking for a prescription.

The Bottom Line on Low Dose Naltrexone

LDN exhibits a ton of potential for providing many benefits. Some studies offer exciting solutions to previously incurable or difficult to treat diseases. Further, LDN can be an affordable treatment method for many and does not appear to have any extreme side effects.

However great LDN’s potential might be, the prescription is still woefully understudied in low doses. Many positive studies include major errors such as low sample sizes, lack of attempts to reproduce results, or failure to control with a placebo group. Further, using Naltrexone in small quantities does not adhere to the original, FDA approved the use of the drug.

LDN should not be completely discounted as a treatment for several illnesses and ailments, but it cannot be viewed as a miracle cure-all to everything that plagues the human body. The medication offers a lot of positive possibilities, but also boasts some claims that appear to be too good to be true. More insight into LDN is needed; that insight will only come through rigorous research, well-crafted clinical trials, and time.

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