Table of ContentsView AllTable of ContentsOverviewUsesDosageSide EffectsInteractions
Table of ContentsView All
View All
Table of Contents
Overview
Uses
Dosage
Side Effects
Interactions
Low-dose naltrexone therapy is sometimes used to relieve pain and fatigue associated withfibromyalgiaandchronic fatigue syndrome. Researchers are also looking at its effectiveness in treating multiple sclerosis, Crohn’s disease, and long COVID.
Naltrexone is a medication that has been used to treat alcohol dependence and opioid-use disorder for more than 30 years. More recently, researchers found low doses of naltrexone—about 1/30th the standard dose—may be useful for other conditions.
This article discusses low-dose naltrexone benefits and uses related to fibromyalgia, chronic fatigue syndrome, and other conditions. It also explains the side effects of LDN therapy and what to avoid when taking naltrexone.
Jack Hollingsworth / Getty Images
How Does Low-Dose Naltrexone Work?
Researchers are not entirely sure how lower doses of naltrexone work to relieve fibromyalgia, chronic fatigue syndrome, and potentially other conditions. Proposed pathways include:
Low-Dose Naltrexone Uses
At very low doses, naltrexone may help people with fibromyalgia, chronic fatigue syndrome, and other conditions. Here is a closer look at low-dose naltrexone benefits and uses.
Fibromyalgia
A review of studies found that LDN could help reduce pain and improve quality of life in people with fibromyalgia, but it also noted that larger studies are needed to confirm the results.
LDN is not FDA-approved for fibromyalgia but is sometimes prescribed for off-label use.
Pain Relief for Inflammation in Fibromyalgia
Chronic Fatigue Syndrome
Chronic fatigue syndrome is also known asmyalgic encephalomyelitis. The condition involves deep fatigue, unrefreshing sleep, exercise intolerance, and neurological issues referred to as “brain fog.” Every person with chronic fatigue syndrome has a unique set of symptoms and degree of intensity.
LDN is sometimes prescribed off-label for chronic fatigue syndrome. There is growing evidence that some individuals have seen a reduction in their symptoms while using LDN.
Research suggests that individuals with chronic fatigue syndrome may haveneuroinflammation, which is an inflammatory response in the brain or spinal cord. Because LDN may have an impact on inflammation in the nervous system, it’s understandable why this may be a helpful treatment for some.
Multiple Sclerosis
Multiple sclerosisis an autoimmune condition where the body’s immune system mistakenly attacks the protective covering of certain nerve cells. This can cause pain, muscle weakness, fatigue, and cognitive problems.
A few studies have found that LDN may be helpful in improving fatigue and quality of life in people with multiple sclerosis (MS). However, although clinical trials have established the safety and tolerability of LDN, it’s difficult to draw any conclusions about efficacy because most of the studies have been small, poorly designed, or used animal models. More research could help confirm whether LDN is an effective treatment for MS.
Long COVID
Around 38% of those with COVID-19 will continue to have symptoms for longer than 12 weeks.When this happens, it is called long COVID.
A few studies have looked at LDN as a treatment for patients with long COVID. One found that LDN is safe for people with long COVID, and that it could help reduce symptoms and improve well being. The study was small, however, and larger studies would be needed before it will be clear how LDN works in people with this condition.
Crohn’s Disease
Crohn’s disease is a chronic inflammatory condition that affects the tissues in your digestive tract.
Although LDN has been studied for its potential to reduce the severity of symptoms in people with Crohn’s disease, most of the studies have been small and the outcomes were subjective, which means it’s hard to know how much of an effect, if any, LDN has on the disease. It does appear to be safe and well-tolerated for people with Crohn’s.
Cancer
LDN has also been studied for its anticancer properties. However, studies that have found efficacy against certain cancers have largely been limited to animal models. Animal studies do not always translate well to human beings.
So far there isn’t any research that supports the use of LDN in people with cancer, though the studies that do exist have been inconclusive. More research is needed before LDN can be recommended as a treatment for people with cancer.
Other Uses for Low-Dose Naltrexone
Research shows some promise for low-dose naltrexone in treating these other conditions:
LDN Dosage
For use in treating fibromyalgia or chronic fatigue syndrome, naltrexone is generally given in doses of 4.5 mg or less. Typically, you’ll start at 1.5 mg, work up to 3 mg, then increase to 4.5 mg.
Keep in mind that higher doses of naltrexone have not been shown to have the same symptom-reducing effects for fibromyalgia or chronic fatigue syndrome.
How long does it take for low dose naltrexone to work?The time it takes for low-dose naltrexone to become effective varies from person to person. In clinical studies, patients taking low-dose naltrexone to treat chronic pain have reported a time frame of one to three months before they began to experience symptom relief.
How long does it take for low dose naltrexone to work?
The time it takes for low-dose naltrexone to become effective varies from person to person. In clinical studies, patients taking low-dose naltrexone to treat chronic pain have reported a time frame of one to three months before they began to experience symptom relief.
Difference Between Drug Dose and Dosage
Research shows that the drug seems safe for long-term use. As long as naltrexone benefits you, you can take it on an ongoing basis.
Side Effects of Low-Dose Naltrexone
While LDN appears to be well-tolerated, known side effects of naltrexone includedizziness,headache, difficulty sleeping (insomnia),vivid dreams,nausea, vomiting, decreased appetite, joint pain, muscle cramps,tooth pain, and anxiety. Pain and swelling at the injection site may also occur if naltrexone is injected rather than taken as a pill.
Long-term side effects are uncommon with low-dose naltrexone. These tend to occur more often at higher doses. In rare instances, there can be severe side effects such as increased blood pressure or heart rate, confusion, depression, and allergic reactions. Contact your healthcare provider right away if you experience any of these.
People withkidney diseaseorliver diseasemay need to speak with their doctor before starting LDN. Those who are pregnant or breastfeeding should also speak with their doctor before starting this medication.
You should avoid alcohol and certain other drugs when taking low-dose naltrexone.
Because low-dose naltrexone blocks opioid receptors, it’s important not to take this medication withopioid pain relieverssuch asUltram (tramadol)andOxyContin (oxycodone).Doing so may cause opioid withdrawal symptoms.
Cytochrome P450 (CYP450) is a protein that helps your body metabolize drugs. Because naltrexone can inhibit these enzymes, it should not be taken with CYP450 substrate medications such as:
Summary
Researchers aren’t sure exactly how LDN works when it comes to conditions like fibromyalgia and chronic fatigue syndrome. Some believe it may act as an anti-inflammatory agent, help balance the immune system, or trigger the release of endorphins.
In research and case studies, LDN has been shown to help decrease symptoms with minimal side effects. However, most of these studies have been small and more research is needed.
19 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Bolton MJ, Chapman BP, Van Marwijk H.Low-dose naltrexone as a treatment for chronic fatigue syndrome.BMJ Case Rep. 2020;13(1):e232502. doi:10.1136/bcr-2019-232502U.S. Food and Drug Administration.Revia.Substance Abuse and Mental Health Services Administration.Naltrexone.Khedr EM, Omran EAH, Ismail NM, et al.Effects of transcranial direct current stimulation on pain, mood and serum endorphin level in the treatment of fibromyalgia: a double blinded, randomized clinical trial.Brain Stimulation. 2017;10(5):893-901. doi:10.1016/j.brs.2017.06.006Patten DK, Schultz BG, Berlau DJ.The safety and efficacy of low-dose naltrexone in the management of chronic pain and inflammation in multiple sclerosis, fibromyalgia, Crohn’s disease, and other chronic pain disorders.Pharmacotherapy. 2018;38(3):382-389. doi:10.1002/phar.2086Younger J, Parkitny L, McLain D.The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain.Clin Rheumatol. 2014;33(4):451–459. doi:10.1007/s10067-014-2517-2O’Kelly B, Vidal L, McHugh T, Woo J, Avramovic G, Lambert JS.Safety and efficacy of low dose naltrexone in a long covid cohort; an interventional pre-post study.Brain Behav Immun Health. 2022;24:100485. doi:10.1016/j.bbih.2022.100485National Multiple Sclerosis Society.Low-dose naltrexone.LDN Research Trust.Can you use Low Dose Naltrexone (LDN) for dementia?Srinivasan A, Dutta P, Bansal D, Chakrabarti A, Bhansali AK, Hota D.Efficacy and safety of low-dose naltrexone in painful diabetic neuropathy: A randomized, double-blind, active-control, crossover clinical trial.J Diabetes. 2021;13(10):770-778. doi:10.1111/1753-0407.13202Brewer, K. L., Mainhart, A., & Meggs, W. J. (2018).Double-blinded placebo-controlled cross-over pilot trial of naltrexone to treat Gulf War Illness.Fatigue: Biomedicine, Health & Behavior,6(3), 132–140. doi:10.1080/21641846.2018.1477034Papay K, Xie SX, Stern M, et al.Naltrexone for impulse control disorders in Parkinson disease: a placebo-controlled study.Neurology. 2014;83(9):826-833. doi:10.1212/WNL.0000000000000729Younger J, Parkitny L, McLain D.The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain.Clin Rheumatol. 2014;33(4):451-459. doi:10.1007/s10067-014-2517-2Plank JR, Glover SC, Moloney BD, et al.A randomized, double-blind, placebo-controlled, hybrid parallel-arm study of low-dose naltrexone as an adjunctive anti-inflammatory treatment for major depressive disorder.Trials. 2022;23(1):822. Published 2022 Sep 30. doi:10.1186/s13063-022-06738-3McKenzie-Brown AM, Boorman DW, Ibanez KR, Agwu E, Singh V.Low-dose naltrexone (LDN) for chronic pain at a single institution: A case series.J Pain Res. 2023;16:1993-1998. doi:10.2147/JPR.S389957Ludwig MD, Turel AP, Zagon IS, McLaughlin PJ.Long-term treatment with low dose naltrexone maintains stable health in patients with multiple sclerosis.Multiple Sclerosis Journal - Experimental, Translational and Clinical. 2016;2:205521731667224. doi:10.1177%2F2055217316672242National Alliance on Mental Illness.Naltrexone (ReVia).AlRabiah H, Ahad A, Mostafa GAE, Al-Jenoobi FI.Effect of naltrexone hydrochloride on cytochrome P450 1A2, 2C9, 2D6, and 3A4 activity in human liver microsomes.Eur J Drug Metab Pharmacokinet. 2018;43(6):707-713. doi:10.1007/s13318-018-0482-xGuerzoni S, Pellesi L, Pini LA, Caputo F.Drug-drug interactions in the treatment for alcohol use disorders: A comprehensive review.Pharmacol Res. 2018;133:65-76. doi:10.1016/j.phrs.2018.04.024
19 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Bolton MJ, Chapman BP, Van Marwijk H.Low-dose naltrexone as a treatment for chronic fatigue syndrome.BMJ Case Rep. 2020;13(1):e232502. doi:10.1136/bcr-2019-232502U.S. Food and Drug Administration.Revia.Substance Abuse and Mental Health Services Administration.Naltrexone.Khedr EM, Omran EAH, Ismail NM, et al.Effects of transcranial direct current stimulation on pain, mood and serum endorphin level in the treatment of fibromyalgia: a double blinded, randomized clinical trial.Brain Stimulation. 2017;10(5):893-901. doi:10.1016/j.brs.2017.06.006Patten DK, Schultz BG, Berlau DJ.The safety and efficacy of low-dose naltrexone in the management of chronic pain and inflammation in multiple sclerosis, fibromyalgia, Crohn’s disease, and other chronic pain disorders.Pharmacotherapy. 2018;38(3):382-389. doi:10.1002/phar.2086Younger J, Parkitny L, McLain D.The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain.Clin Rheumatol. 2014;33(4):451–459. doi:10.1007/s10067-014-2517-2O’Kelly B, Vidal L, McHugh T, Woo J, Avramovic G, Lambert JS.Safety and efficacy of low dose naltrexone in a long covid cohort; an interventional pre-post study.Brain Behav Immun Health. 2022;24:100485. doi:10.1016/j.bbih.2022.100485National Multiple Sclerosis Society.Low-dose naltrexone.LDN Research Trust.Can you use Low Dose Naltrexone (LDN) for dementia?Srinivasan A, Dutta P, Bansal D, Chakrabarti A, Bhansali AK, Hota D.Efficacy and safety of low-dose naltrexone in painful diabetic neuropathy: A randomized, double-blind, active-control, crossover clinical trial.J Diabetes. 2021;13(10):770-778. doi:10.1111/1753-0407.13202Brewer, K. L., Mainhart, A., & Meggs, W. J. (2018).Double-blinded placebo-controlled cross-over pilot trial of naltrexone to treat Gulf War Illness.Fatigue: Biomedicine, Health & Behavior,6(3), 132–140. doi:10.1080/21641846.2018.1477034Papay K, Xie SX, Stern M, et al.Naltrexone for impulse control disorders in Parkinson disease: a placebo-controlled study.Neurology. 2014;83(9):826-833. doi:10.1212/WNL.0000000000000729Younger J, Parkitny L, McLain D.The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain.Clin Rheumatol. 2014;33(4):451-459. doi:10.1007/s10067-014-2517-2Plank JR, Glover SC, Moloney BD, et al.A randomized, double-blind, placebo-controlled, hybrid parallel-arm study of low-dose naltrexone as an adjunctive anti-inflammatory treatment for major depressive disorder.Trials. 2022;23(1):822. Published 2022 Sep 30. doi:10.1186/s13063-022-06738-3McKenzie-Brown AM, Boorman DW, Ibanez KR, Agwu E, Singh V.Low-dose naltrexone (LDN) for chronic pain at a single institution: A case series.J Pain Res. 2023;16:1993-1998. doi:10.2147/JPR.S389957Ludwig MD, Turel AP, Zagon IS, McLaughlin PJ.Long-term treatment with low dose naltrexone maintains stable health in patients with multiple sclerosis.Multiple Sclerosis Journal - Experimental, Translational and Clinical. 2016;2:205521731667224. doi:10.1177%2F2055217316672242National Alliance on Mental Illness.Naltrexone (ReVia).AlRabiah H, Ahad A, Mostafa GAE, Al-Jenoobi FI.Effect of naltrexone hydrochloride on cytochrome P450 1A2, 2C9, 2D6, and 3A4 activity in human liver microsomes.Eur J Drug Metab Pharmacokinet. 2018;43(6):707-713. doi:10.1007/s13318-018-0482-xGuerzoni S, Pellesi L, Pini LA, Caputo F.Drug-drug interactions in the treatment for alcohol use disorders: A comprehensive review.Pharmacol Res. 2018;133:65-76. doi:10.1016/j.phrs.2018.04.024
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Bolton MJ, Chapman BP, Van Marwijk H.Low-dose naltrexone as a treatment for chronic fatigue syndrome.BMJ Case Rep. 2020;13(1):e232502. doi:10.1136/bcr-2019-232502U.S. Food and Drug Administration.Revia.Substance Abuse and Mental Health Services Administration.Naltrexone.Khedr EM, Omran EAH, Ismail NM, et al.Effects of transcranial direct current stimulation on pain, mood and serum endorphin level in the treatment of fibromyalgia: a double blinded, randomized clinical trial.Brain Stimulation. 2017;10(5):893-901. doi:10.1016/j.brs.2017.06.006Patten DK, Schultz BG, Berlau DJ.The safety and efficacy of low-dose naltrexone in the management of chronic pain and inflammation in multiple sclerosis, fibromyalgia, Crohn’s disease, and other chronic pain disorders.Pharmacotherapy. 2018;38(3):382-389. doi:10.1002/phar.2086Younger J, Parkitny L, McLain D.The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain.Clin Rheumatol. 2014;33(4):451–459. doi:10.1007/s10067-014-2517-2O’Kelly B, Vidal L, McHugh T, Woo J, Avramovic G, Lambert JS.Safety and efficacy of low dose naltrexone in a long covid cohort; an interventional pre-post study.Brain Behav Immun Health. 2022;24:100485. doi:10.1016/j.bbih.2022.100485National Multiple Sclerosis Society.Low-dose naltrexone.LDN Research Trust.Can you use Low Dose Naltrexone (LDN) for dementia?Srinivasan A, Dutta P, Bansal D, Chakrabarti A, Bhansali AK, Hota D.Efficacy and safety of low-dose naltrexone in painful diabetic neuropathy: A randomized, double-blind, active-control, crossover clinical trial.J Diabetes. 2021;13(10):770-778. doi:10.1111/1753-0407.13202Brewer, K. L., Mainhart, A., & Meggs, W. J. (2018).Double-blinded placebo-controlled cross-over pilot trial of naltrexone to treat Gulf War Illness.Fatigue: Biomedicine, Health & Behavior,6(3), 132–140. doi:10.1080/21641846.2018.1477034Papay K, Xie SX, Stern M, et al.Naltrexone for impulse control disorders in Parkinson disease: a placebo-controlled study.Neurology. 2014;83(9):826-833. doi:10.1212/WNL.0000000000000729Younger J, Parkitny L, McLain D.The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain.Clin Rheumatol. 2014;33(4):451-459. doi:10.1007/s10067-014-2517-2Plank JR, Glover SC, Moloney BD, et al.A randomized, double-blind, placebo-controlled, hybrid parallel-arm study of low-dose naltrexone as an adjunctive anti-inflammatory treatment for major depressive disorder.Trials. 2022;23(1):822. Published 2022 Sep 30. doi:10.1186/s13063-022-06738-3McKenzie-Brown AM, Boorman DW, Ibanez KR, Agwu E, Singh V.Low-dose naltrexone (LDN) for chronic pain at a single institution: A case series.J Pain Res. 2023;16:1993-1998. doi:10.2147/JPR.S389957Ludwig MD, Turel AP, Zagon IS, McLaughlin PJ.Long-term treatment with low dose naltrexone maintains stable health in patients with multiple sclerosis.Multiple Sclerosis Journal - Experimental, Translational and Clinical. 2016;2:205521731667224. doi:10.1177%2F2055217316672242National Alliance on Mental Illness.Naltrexone (ReVia).AlRabiah H, Ahad A, Mostafa GAE, Al-Jenoobi FI.Effect of naltrexone hydrochloride on cytochrome P450 1A2, 2C9, 2D6, and 3A4 activity in human liver microsomes.Eur J Drug Metab Pharmacokinet. 2018;43(6):707-713. doi:10.1007/s13318-018-0482-xGuerzoni S, Pellesi L, Pini LA, Caputo F.Drug-drug interactions in the treatment for alcohol use disorders: A comprehensive review.Pharmacol Res. 2018;133:65-76. doi:10.1016/j.phrs.2018.04.024
Bolton MJ, Chapman BP, Van Marwijk H.Low-dose naltrexone as a treatment for chronic fatigue syndrome.BMJ Case Rep. 2020;13(1):e232502. doi:10.1136/bcr-2019-232502
U.S. Food and Drug Administration.Revia.
Substance Abuse and Mental Health Services Administration.Naltrexone.
Khedr EM, Omran EAH, Ismail NM, et al.Effects of transcranial direct current stimulation on pain, mood and serum endorphin level in the treatment of fibromyalgia: a double blinded, randomized clinical trial.Brain Stimulation. 2017;10(5):893-901. doi:10.1016/j.brs.2017.06.006
Patten DK, Schultz BG, Berlau DJ.The safety and efficacy of low-dose naltrexone in the management of chronic pain and inflammation in multiple sclerosis, fibromyalgia, Crohn’s disease, and other chronic pain disorders.Pharmacotherapy. 2018;38(3):382-389. doi:10.1002/phar.2086
Younger J, Parkitny L, McLain D.The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain.Clin Rheumatol. 2014;33(4):451–459. doi:10.1007/s10067-014-2517-2
O’Kelly B, Vidal L, McHugh T, Woo J, Avramovic G, Lambert JS.Safety and efficacy of low dose naltrexone in a long covid cohort; an interventional pre-post study.Brain Behav Immun Health. 2022;24:100485. doi:10.1016/j.bbih.2022.100485
National Multiple Sclerosis Society.Low-dose naltrexone.
LDN Research Trust.Can you use Low Dose Naltrexone (LDN) for dementia?
Srinivasan A, Dutta P, Bansal D, Chakrabarti A, Bhansali AK, Hota D.Efficacy and safety of low-dose naltrexone in painful diabetic neuropathy: A randomized, double-blind, active-control, crossover clinical trial.J Diabetes. 2021;13(10):770-778. doi:10.1111/1753-0407.13202
Brewer, K. L., Mainhart, A., & Meggs, W. J. (2018).Double-blinded placebo-controlled cross-over pilot trial of naltrexone to treat Gulf War Illness.Fatigue: Biomedicine, Health & Behavior,6(3), 132–140. doi:10.1080/21641846.2018.1477034
Papay K, Xie SX, Stern M, et al.Naltrexone for impulse control disorders in Parkinson disease: a placebo-controlled study.Neurology. 2014;83(9):826-833. doi:10.1212/WNL.0000000000000729
Younger J, Parkitny L, McLain D.The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain.Clin Rheumatol. 2014;33(4):451-459. doi:10.1007/s10067-014-2517-2
Plank JR, Glover SC, Moloney BD, et al.A randomized, double-blind, placebo-controlled, hybrid parallel-arm study of low-dose naltrexone as an adjunctive anti-inflammatory treatment for major depressive disorder.Trials. 2022;23(1):822. Published 2022 Sep 30. doi:10.1186/s13063-022-06738-3
McKenzie-Brown AM, Boorman DW, Ibanez KR, Agwu E, Singh V.Low-dose naltrexone (LDN) for chronic pain at a single institution: A case series.J Pain Res. 2023;16:1993-1998. doi:10.2147/JPR.S389957
Ludwig MD, Turel AP, Zagon IS, McLaughlin PJ.Long-term treatment with low dose naltrexone maintains stable health in patients with multiple sclerosis.Multiple Sclerosis Journal - Experimental, Translational and Clinical. 2016;2:205521731667224. doi:10.1177%2F2055217316672242
National Alliance on Mental Illness.Naltrexone (ReVia).
AlRabiah H, Ahad A, Mostafa GAE, Al-Jenoobi FI.Effect of naltrexone hydrochloride on cytochrome P450 1A2, 2C9, 2D6, and 3A4 activity in human liver microsomes.Eur J Drug Metab Pharmacokinet. 2018;43(6):707-713. doi:10.1007/s13318-018-0482-x
Guerzoni S, Pellesi L, Pini LA, Caputo F.Drug-drug interactions in the treatment for alcohol use disorders: A comprehensive review.Pharmacol Res. 2018;133:65-76. doi:10.1016/j.phrs.2018.04.024
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
