Näytönastekatsaukset

Naltrexone for fibromyalgia

Näytönastekatsaukset

3.3.2026

Aleksi Varinen and Aleksi Raudasoja

Level of evidence: B

Low dose Naltrexone likely provides little to no benefit on fibromyalgia symptoms.

Two small blinded randomized trials measured effectiveness of Naltrexone on fibromyalgia symptoms. The larger study found 0.34 points reduction in pain (95% confidence interval -0.95 to 0.27, scale from 0 to 10), which translates to about 6% reduction in pain (1). The total fibromyalgia symptoms decreased - 2.50 points (–6.73 to 1.72, FIQR [0-100]), also suggesting little or no benefit from the treatment.

Table 1. Description of the included studies
Reference	Study type	Population	Intervention and comparison	Outcomes	Risk of bias
RCT=randomized controlled trial; SR=systematic review; MA=meta-analysis; FIQR = Fibromyalgia impact questionnaire revised; SPIR = summed pain intensity raiting
«Due Bruun K, Christensen R, Amris K, et al. Naltrexone 6 mg once daily versus placebo in women with fibromyalgia: a randomised, double-blind, placebo-controlled trial. Lancet Rheumatol 2024;6(1):e31-e»1	RCT	Women, age 18-64, with fibromyalgia.	Naltrexone 6 mg once daily vs placebo	BPI	low
«Bested K, Jensen LM, Andresen T, et al. Low-dose naltrexone for treatment of pain in patients with fibromyalgia: a randomized, double-blind, placebo-controlled, crossover study. Pain Rep 2023;8(4):e10»2	RCT, crossover study	Premenopausal women with fibromyalgia, referred to multidisciplinary pain treatment	Naltrexone 4,5 mg once daily vs placebo	FIQR, SPIR	low
«Younger J, Noor N, McCue R, et al. Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing »3	RCT, crossover study	Women, age 18-64 with fibromyalgia.	Naltrexone 4,5 mg once daily vs placebo	Pain	low

Table 2. Additional comments for included studies
Reference	Comments
«Due Bruun K, Christensen R, Amris K, et al. Naltrexone 6 mg once daily versus placebo in women with fibromyalgia: a randomised, double-blind, placebo-controlled trial. Lancet Rheumatol 2024;6(1):e31-e»1	9/99 dropped out from the study before the end of follow up but were included in the ITT analysis.
«Bested K, Jensen LM, Andresen T, et al. Low-dose naltrexone for treatment of pain in patients with fibromyalgia: a randomized, double-blind, placebo-controlled, crossover study. Pain Rep 2023;8(4):e10»2	Fibromyalgia diagnosed by rheumatologist.
«Younger J, Noor N, McCue R, et al. Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing »3	Participants with joint inflammation or with history of rheumatic diseases were excluded. Naltrexone 12 weeks and placebo 4 weeks.

Table 3. Outcome 1 – FIQR [0-100]
Reference	Number of studies and number of patients (I/C)	Follow-up time	Mean change from baseline (sd) I	Mean change from baseline (sd) C	Mean difference (95% CI)
Level of evidence: moderate Assess the risk of bias and delete irrelevant sources of bias: The quality of evidence is downgraded due to imprecision. I=intervention; C=comparison; CI=confidence interval
«Due Bruun K, Christensen R, Amris K, et al. Naltrexone 6 mg once daily versus placebo in women with fibromyalgia: a randomised, double-blind, placebo-controlled trial. Lancet Rheumatol 2024;6(1):e31-e»1	50/49	12 weeks	- 10.8 (–13.8 to –7.8)	- 8.3 (–11.3 to –5.3)	- 2.50 (–6.73 to 1.72)
«Bested K, Jensen LM, Andresen T, et al. Low-dose naltrexone for treatment of pain in patients with fibromyalgia: a randomized, double-blind, placebo-controlled, crossover study. Pain Rep 2023;8(4):e10»2	26/26	3 weeks + 3 weeks			−2.50, CI not reported, P-value = 0.34

Table 4. Outcome 2 – Pain [0-10]
Reference	Number of studies and number of patients (I/C)	Follow-up time	Mean change from baseline I (95% CI)	Mean change from baseline C (95% CI)	Mean difference (95% CI)
Level of evidence: moderate Assess the risk of bias and delete irrelevant sources of bias: The quality of evidence is downgraded due to imprecision. I=intervention; C=comparison; CI=confidence interval
«Due Bruun K, Christensen R, Amris K, et al. Naltrexone 6 mg once daily versus placebo in women with fibromyalgia: a randomised, double-blind, placebo-controlled trial. Lancet Rheumatol 2024;6(1):e31-e»1	49/50	12 weeks	–1,3 (–1,7 to –0,8)	–0,9 (–1,4 to –0,5)	–0,34 (–0,95 to 0,27)
«Bested K, Jensen LM, Andresen T, et al. Low-dose naltrexone for treatment of pain in patients with fibromyalgia: a randomized, double-blind, placebo-controlled, crossover study. Pain Rep 2023;8(4):e10»2	26/26	3 weeks + 3 weeks			−0.40, CI not reported, P = 0.68
«Younger J, Noor N, McCue R, et al. Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing »3	14/14	12 weeks	-11.2	-15.5	not reported, p = 0.016

References

Due Bruun K, Christensen R, Amris K, et al. Naltrexone 6 mg once daily versus placebo in women with fibromyalgia: a randomised, double-blind, placebo-controlled trial. Lancet Rheumatol 2024;6(1):e31-e39 «PMID: 38258677»PubMed
Bested K, Jensen LM, Andresen T, et al. Low-dose naltrexone for treatment of pain in patients with fibromyalgia: a randomized, double-blind, placebo-controlled, crossover study. Pain Rep 2023;8(4):e1080 «PMID: 38226027»PubMed
Younger J, Noor N, McCue R, et al. Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing daily pain levels. Arthritis Rheum 2013;65(2):529-38 «PMID: 23359310»PubMed