For the millions of adults managing chronic joint, back, or soft-tissue pain, the appeal of a non-opioid, low-side-effect option is enormous. A systematic review now places melatonin — already well-known as a sleep aid — under rigorous scrutiny as a potential analgesic, and the findings complicate the simple narrative in both directions.
Drawing on 23 randomized controlled trials encompassing 2,028 participants, this meta-analysis published in Pain examined melatonin's performance against both placebo and active analgesic comparators across two distinct clinical populations: those with chronic musculoskeletal pain and those recovering from orthopedic or musculoskeletal surgery. In the chronic pain population, the headline result was a statistical wash against placebo — a mean pain reduction of roughly 6.8 points on a 100-point scale that did not reach significance. However, when only low-risk-of-bias trials were retained in sensitivity analysis, a meaningful signal emerged (approximately −10 points vs. placebo). Against active analgesic comparators, melatonin outperformed by about 11 points — a clinically relevant margin. In the postoperative context, melatonin consistently beat placebo and held its own against conventional pain medications. Sleep quality improvement was a secondary but notable benefit in chronic pain patients specifically.
The study represents the most comprehensive synthesis to date on this question and arrives at a nuanced conclusion that deserves careful interpretation. The overall evidence certainty by GRADE standards is likely low to moderate, and the comparison against active controls — rather than placebo — is the stronger signal precisely because analgesic comparators are already clinically meaningful benchmarks. Melatonin's plausibility as an analgesic rests on its anti-inflammatory properties, modulation of opioid receptor pathways, and antioxidant activity in neural tissue — mechanisms increasingly documented in preclinical literature. What this analysis cannot resolve is optimal dosing, timing, or duration of use, and the 23-trial base across two heterogeneous pain populations limits subgroup confidence. Still, given the favorable safety profile — adverse events were mild and transient — this is an incrementally important finding for integrative pain management, particularly for patients seeking adjunctive options alongside conventional therapy.