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“I’m always excited when we find alternative pain options that could potentially be helpful with minimal side effects,” says Alba Azola, MD, an assistant professor of physical medicine and rehabilitation at Johns Hopkins Medicine in Baltimore, who wasn’t involved in the research.
The findings suggest melatonin could be a good add-on for existing pain management plans, Dr. Azola says. “I think it’s a good adjunct, especially for patients with chronic pain whose sleep is interrupted because of the pain.”
Analysis Included Over 2,000 People With Muscle and Joint Pain
The new paper was a systematic review and meta-analysis, meaning researchers gathered data from previously published randomized controlled trials and combined the results to look for a clearer overall pattern.
The study included 23 trials with more than 2,000 participants. All had either chronic musculoskeletal pain or pain after musculoskeletal surgery, which could include low back pain, osteoarthritis, fibromyalgia, and pain after joint replacement or spine surgery.
Some trials compared melatonin with a placebo, or dummy pill. Others compared melatonin with pain medicines or other drugs. Melatonin doses ranged from 1 to 10 milligrams (mg).
To make results easier to compare across studies, researchers converted pain and sleep scores to a 0 to 100 scale, where 0 meant no pain and 100 meant the worst pain possible.
Melatonin Linked With Less Chronic Pain and Better Sleep
The results showed that taking melatonin was tied to lower pain scores and better sleep quality for people with chronic muscle or joint pain. “The size of the pain-relieving effect was comparable to conventional pain medicines such as NSAIDs,” says lead study author Kangchao Wu, a PhD student at the University of Sydney. Nonsteroidal anti-inflammatory drugs (NSAIDs) include over-the-counter medicines like acetaminophen and ibuprofen.
The main findings included:
- Across all comparison groups, melatonin reduced chronic pain by about 9 points on the 100-point scale.
- Melatonin improved sleep quality by about 11 points.
- For pain after surgery, melatonin did better than placebo, but the effect was small — about 2.5 to 3.5 points. The authors wrote that this was unlikely to be meaningful for most patients.
- For chronic pain, longer treatment duration, not higher dose, was linked with more favorable effects, but the finding is limited by the relatively small number of studies.
The researchers didn’t find a dose-dependent relationship between melatonin and pain reduction — meaning higher doses didn’t necessarily lead to more pain relief.
“We tried, but we didn’t find an optimal dose of melatonin for treating chronic musculoskeletal pain,” says Wu.
Side effects in the review were generally mild and temporary. The most commonly reported side effects were nausea or vomiting, dizziness, headache, and drowsiness, and no serious adverse events were reported in the trials.
The Link Between Sleep and Chronic Pain
Daniel Clauw, MD, a professor of anesthesiology, medicine, and psychiatry at the University of Michigan in Ann Arbor, says the results fit with what pain experts already know about sleep and pain.
“Getting better and deeper sleep is clearly important in chronic pain — especially nociplastic pain,” says Dr. Clauw, who was not involved in the study.
How Might Melatonin Ease Pain?
Melatonin is best known for helping regulate the body’s sleep-wake cycle, but researchers think it may influence pain in more than one way.
The first is an indirect pathway: Melatonin may help reduce pain by improving sleep, which can further improve mood, reduce anxiety, and help people stay more active during the day, all of which may in turn help reduce pain intensity, says Wu.
It could also impact pain directly. Melatonin may have its own pain-relieving properties, including antioxidant and anti-inflammatory effects that could help modulate pain, he says.
The Study Had Strengths, but the Evidence Isn’t Final
The review had several strengths. It included only randomized controlled trials, focused specifically on musculoskeletal pain, compared melatonin with both placebo and active treatments, and separately analyzed chronic and postoperative pain.
There were limitations to the analysis. The chronic pain findings were rated as low certainty for pain and moderate certainty for sleep quality, meaning future studies could change the estimates. Many trials were small, dosing varied widely, and most studies did not follow people beyond three months.
What to Know Before Trying Melatonin for Chronic Pain
Clauw says melatonin is “well worth a try” for some people with chronic pain and sleep problems because it “seems quite safe and may be helpful.”
Wu adds that adults “should still speak with a doctor or pharmacist before trying melatonin, especially if they are taking other medications or have underlying health conditions.”
Azola recommends a “start low and go slow” approach. For many people, that might mean starting with 1 mg of melatonin and increasing only if needed, with a common range of about 3 to 6 mg.
“More is not more when it comes to melatonin,” she says. “Doses greater than 10 milligrams can sometimes cause sleep disruption and have the opposite effect on sleep.”
Long-term use of higher doses may also make melatonin less effective, Azola adds.
She also recommends choosing supplements carefully. “Dietary supplements are not reviewed by the U.S. Food and Drug Administration for safety, effectiveness, or manufacturing quality before they reach the market, and independent testing has found that some over-the-counter melatonin products contain different amounts than the label says,” she notes.
Look for brands that have been validated by an independent third-party and discuss with your healthcare provider.
