Trial reportPain medicine (Malden, Mass.)
Fibromyalgia symptoms are reduced by low-dose naltrexone: a pilot study.
Trial report in Pain medicine (Malden, Mass.). The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 5 registered trials, which are not on this map. Cited by 101 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
A Clinical Trial to Assess a Single Dose of Low-Dose Naltrexone and Acetaminophen Combination and Its Components in the Acute Treatment of Migraine
IC PaIN Trial: Interstitial Cystitis Pain Improvement With Naltrexone, the Effect of Low Dose Naltrexone on Symptoms and Pain of Patients With Interstitial Cystitis/Painful Bladder Syndrome a Randomized Placebo-controlled Prospective Trial
Association of Low Doses of Naltrexone and Transcranial Direct Current Stimulation in Fibromyalgia: Randomized Clinical Trial, Blind, Controlled With Placebo
Safety and Efficacy of Naltrexone/Acetaminophen for the Acute Treatment of Migraine: A Single-Site, Phase 2 Randomized Trial
A Clinical Trial to Assess a Single Dose of Low-Dose Naltrexone and Acetaminophen Combination and Its Components in the Acute Treatment of Migraine
Who cites it
101 citing papers in PubMed, 3 syntheses or guidelines pooled it, 205 citations in OpenAlex.
- Assessing Ethnic Minority Representation in Fibromyalgia Clinical Trials: A Systematic Review of Recruitment Demographics.International journal of environmental research and public health · 2023Pooled it
- Low-Dose Naltrexone for Chronic Pain: Update and Systemic Review.Current pain and headache reports · 2020Pooled it
- Pain Assessment--Can it be Done with a Computerised System? A Systematic Review and Meta-Analysis.International journal of environmental research and public health · 2016Pooled it
- Efficacy of Low-Dose Naltrexone in Women With Fibromyalgia Syndrome: A 12-Month Randomised, Double-Blind, Placebo-Controlled Single-Centre Clinical Trial (INNOVA Study).European journal of pain (London, England) · 2026Trial
- Low-dose naltrexone as an adjunctive treatment for major depressive disorder: findings from a randomized, double-blind, placebo-controlled hybrid parallel-arm study.Frontiers in pharmacology · 2026Trial
- Effects of low-dose naltrexone on quality of life in high-grade glioma patients: a placebo-controlled, double-blind randomized trial.Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer · 2022Trial
- Low-Dose Dextromethorphan for the Treatment of Fibromyalgia Pain: Results from a Longitudinal, Single-Blind, Placebo-Controlled Pilot Trial.Journal of pain research · 2021Trial
- Low dose Naltrexone for induction of remission in inflammatory bowel disease patients.Journal of translational medicine · 2018Trial
- Trial
- Endogenous opioid inhibition of chronic low-back pain influences degree of back pain relief after morphine administration.Regional anesthesia and pain medicineTrial
- Association of low-dose naltrexone and transcranial direct current stimulation in fibromyalgia: a randomized, double-blinded, parallel clinical trial.Brazilian journal of anesthesiology (Elsevier)Trial
- Low-Dose Naltrexone: What is the Evidence? A Narrative Review.Advances in therapy · 2026Review
- Pain-Affective Disorder Comorbidity in the Temporomandibular Disorders: From Mechanistic Insights to Clinical Management.Neuroscience bulletin · 2026Review
- The expanding potential of low-dose naltrexone in clinical practice with a focus on long COVID.The mental health clinician · 2026Article
- Low-Dose Naltrexone in Chronic Pain Management: Mechanisms, Evidence, and Clinical Implications.Journal of personalized medicine · 2026Review
- Low dose naltrexone for fibromyalgia: case series demonstrating pain relief and other health benefits.Frontiers in pain research (Lausanne, Switzerland) · 2026Article
- Morphological Brain Alterations and Network Disorganizations in Individuals With Substance Use Disorders: Differential Effects of Heroin Versus Methamphetamine.Brain and behavior · 2025Article
- Descending Pain Modulation in Fibromyalgia: A Short Review of Mechanisms and Biomarkers.Diagnostics (Basel, Switzerland) · 2025Review
- Review
- Article
41 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors at 2 institutions in 1 country.
Funding
Abstract
objectiveFibromyalgia is a chronic pain disorder that is characterized by diffuse musculoskeletal pain and sensitivity to mechanical stimulation. In this pilot clinical trial, we tested the effectiveness of low-dose naltrexone in treating the symptoms of fibromyalgia.
designParticipants completed a single-blind, crossover trial with the following time line: baseline (2 weeks), placebo (2 weeks), drug (8 weeks), and washout (2 weeks). PATIENTS: Ten women meeting criteria for fibromyalgia and not taking an opioid medication.
interventionsNaltrexone, in addition to antagonizing opioid receptors on neurons, also inhibits microglia activity in the central nervous system. At low doses (4.5 mg), naltrexone may inhibit the activity of microglia and reverse central and peripheral inflammation. OUTCOME MEASURES: Participants completed reports of symptom severity everyday, using a handheld computer. In addition, participants visited the lab every 2 weeks for tests of mechanical, heat, and cold pain sensitivity.
resultsLow-dose naltrexone reduced fibromyalgia symptoms in the entire cohort, with a greater than 30% reduction of symptoms over placebo. In addition, laboratory visits showed that mechanical and heat pain thresholds were improved by the drug. Side effects (including insomnia and vivid dreams) were rare, and described as minor and transient. Baseline erythrocyte sedimentation rate predicted over 80% of the variance in drug response. Individuals with higher sedimentation rates (indicating general inflammatory processes) had the greatest reduction of symptoms in response to low-dose naltrexone.
conclusionsWe conclude that low-dose naltrexone may be an effective, highly tolerable, and inexpensive treatment for fibromyalgia.
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Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.