Low dose naltrexone, an inexpensive therapy utilizing the generic drug naltrexone in very low doses, is making news again. Thanks to patient advocacy and nonprofit funding, three leading institutions have launched new clinical trials.
VA Boston Healthcare System:
Low-Dose Naltrexone for Chronic Pain in Osteoarthritis and Inflammatory Arthritis

The study leaders note that “over 100 million Americans report chronic pain. Veterans are disproportionately affected for multiple reasons, including injuries and post-traumatic stress disorder. Treatment for chronic pain is a priority research area for the VA.
One of the most common causes of chronic pain is osteoarthritis (OA). OA is attributable to ‘wear and tear’, but reasons for pain are complex. Inflammatory arthritis (IA) includes multiple severe diseases that affect 2-3% of persons and require treatment with immunosuppressive drugs to prevent joint destruction. Pain often persists despite effective treatment. Pain in arthritis results from multiple sources: inflammation, perception of pain in the joint, and interpretation of pain by the brain. Unfortunately, management of pain in arthritis remains a challenge.”
The researchers believe low dose naltrexone (LDN) is attractive to study because it is safe, and is proposed to work on all three pathways that contribute to pain.
Find out moreUniversity of Alabama:
Immune Effects of Low Dose Naltrexone in Myalgic Encephalopathy / Chronic Fatigue Syndrome (ME/CFS)

The main objective of this study, according to study leaders, “is to test if naltrexone, when taken in low doses, has an anti-inflammatory effect that may be associated with positive clinical outcomes in people with chronic fatigue syndrome (CFS).
The present study is a continuation of prior work in which it was showed that chronic fatigue symptoms are associated with immune activity, and that Low-Dose Naltrexone (LDN) might exert anti-inflammatory effects in fibromyalgia, which is thought to share some pathophysiological and clinical characteristics with CFS.”
Find out moreUniversity of Copenhagen, Denmark:
Low Dose Naltrexone for Treatment of Pain in Patients With Fibromyalgia

“Fibromyalgia syndrome is a prevalent musculoskeletal disorder characterized by pain, profound fatigue, sleep disorder, mood disturbance etc. The prevalence is estimated to be 2-8%.
Treatment of pain in patients with fibromyalgia is often based on opioids. However, opioids may lead to tolerance, addiction and hyperalgesia and alternative treatments are therefore warranted.
Low dose naltrexone (3-5 mg) (LDN) has shown promising results in the treatment of pain in patients with fibromyalgia, but there is a need for further research. At the typical dose of naltrexone, 50 mg, it is an opioid antagonist. However Low Dose Naltrexone (LDN) demonstrates analgesic and anti-inflammatory effects, possibly involving an antagonism of microglia in the CNS.”
The researchers hypothesize that LDN has a better pain-relieving effect than placebo in patients with fibromyalgia (FM). A tentative explanation is that LDN facilitates the body’s natural (endogenous) pain inhibitory system.
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