Chronic Pain? Melatonin May Provide Some Relief, Study Finds

• A new study found melatonin eased chronic musculoskeletal pain about as effectively as over-the-counter painkillers.
• The benefit was clearest for chronic pain, but results for post-surgical pain were less clear, the study found.
• The study reported that melatonin is safe in the short term at low doses, defined as less than 3 months and less than 5 milligrams.
• Experts advise talking with a doctor before trying melatonin for pain, particularly if you don’t currently have trouble sleeping or take other medications.

Poor sleep and pain often reinforce each other. Pain can make sleep harder to come by, and lost sleep can make pain feel more intense.

Research has linked lost sleep to increased inflammation and a weakened pain-control system. That relationship is one reason researchers have begun studying whether melatonin, a hormone that regulates the sleep-wake cycle, might also help manage pain.

The research examined both chronic pain — pain lasting three months or longer — and acute, short-term pain following surgeries for conditions like knee and hip replacements, spinal procedures, and fractures. Here’s what they found.

The researchers say that melatonin’s effects may depend on the type of pain.

For chronic pain, the reduction was large enough to rival common painkillers. For post-surgical pain, the results were less clear.

Lead study author Kangchao Wu, a PhD candidate, physiotherapy researcher, and faculty member at the University of Sydney’s School of Health Sciences, explained the two ways melatonin can help reduce pain. The first is in the makeup of the hormone itself.

“Melatonin may have some intrinsic pain-relieving properties, such as antioxidant and anti-inflammatory effects, which are very crucial effects during the pain process,” Wu told Healthline.

The other is more indirect. “Melatonin can improve people’s sleep, help them feel better, help them move better, reduce anxiety and depression related to pain, and help them stay active during the daytime,” Wu said. “All of that together can help reduce pain intensity.”

The difference, Wu said, comes down to the root causes of each pain type.

“Post-operative pain is more acute. Chronic musculoskeletal pain is often related to long-term conditions, like poor sleep, inflammation, and nervous system sensitivity. That’s maybe why we see a difference in melatonin’s effects between the chronic and post-operative groups,” he said.

Even so, researchers frame melatonin as an add-on option, not a replacement for existing pain treatment.

“Melatonin could be an adjunctive treatment to your existing pain treatments for chronic musculoskeletal pain, especially if you have co-existing sleep problems,” Wu said.

What’s still missing, he noted, is an optimal dose and a clear read on long-term use.

Wu advised those considering melatonin for pain to begin by discussing any sleep troubles with their doctor.

“Melatonin is very well established for short-term treatment of insomnia. Based on current evidence, melatonin is proven to be safe if used short-term and at a low dose,” he said.

Wu said that, based on the study’s findings, short-term use was defined as less than 3 months, and a low dose was defined as less than 5 milligrams, noting that most of the trials included in the study used 3 milligrams.

For people experiencing pain but don’t have trouble sleeping, he recommended a conversation with their doctor before starting melatonin.

Melatonin is generally considered safe, but it may have side effects. Wu’s study analyzed side effects in patients who used the supplements for pain.

”The most common side effects with melatonin were headache, nausea, and daytime drowsiness,” Wu said. “But the side effect rate of melatonin was similar to the placebo group.”

Meaning, people who took melatonin reported side effects at rates similar to those who took a placebo.

Wu’s guidance above is specific to using melatonin for pain. Melatonin carries broader restrictions that apply regardless of why someone takes it.

People with certain health conditions — including rheumatoid arthritis and conditions that affect the kidneys or liver — shouldn’t take it without clearing it with a healthcare professional first.

Because melatonin can interact with other drugs and supplements, anyone taking over-the-counter or prescription medication should talk to their doctor before adding it.

Melatonin is a hormone produced naturally by the pineal gland. It regulates the sleep-wake cycle, increasing as it gets dark and decreasing during daylight.

Synthetic melatonin supplements mimic this effect, and people often take them if they have trouble falling asleep, staying asleep, or waking too early.

Supplements are regulated as food, not as drugs, which leaves manufacturers responsible for their products’ safety.

The Council for Responsible Nutrition (CRN), a supplement industry group, told Healthline that while emerging research suggests uses beyond healthy sleep, dietary supplements are not intended to “treat, cure, or prevent disease.”

Jeff Ventura, CRN’s Vice President of Communications, said that anyone dealing with chronic pain or persistent sleep difficulties “should consult a healthcare professional to determine the most appropriate treatment plan.”

Melatonin is generally recommended for short-term use, though the NIH states that “information on the long-term safety of supplementing with melatonin is lacking.”

Longer courses require a specialist’s guidance. In the trials analyzed for this study, treatment durations ranged from four weeks to three months.

A recent observational study presented at the 2025 American Heart Association (AHA)’s Scientific Sessions linked melatonin use beyond a year to higher rates of heart failure diagnosis and hospitalization in people with insomnia. However, the researchers stopped short of referring to the association as causal.

Still, most experts recommend avoiding long-term use of melatonin as a sleep aid. If practicing healthy sleep hygiene habits doesn’t help you sleep better, it might warrant a conversation with your doctor.