A supplement best known for helping some people get a better night's sleep may also have a surprising painkilling effect on individuals with chronic conditions. This could help reduce the use of pain medications that come with more risks.

Researchers from The University of Sydney set out to investigate if there was a link between chronic pain relief and melatonin use. Analyzing data on 2028 adults with chronic pain conditions from 23 randomized controlled trials across several countries, the team found evidence that melatonin plays a role in relieving symptoms.

Participants with chronic conditions including low back issues, osteoarthritis and fibromyalgia, plus those recovering from surgeries, who took melatonin during a study reported reduced pain across the board. Together, this accounted for an average of around nine points on a 0-100 scale, with the trials featuring the most robust study designs reporting this figure closer to 10 points.

This was similar to the relief reported after taking commonly prescribed pain medications.

Essentially, the results were on par with how opioids, non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol scored in trials.

“Melatonin is already in people’s homes, it’s inexpensive, and we know it’s safe,” says lead author Kangchao Wu from the Musculoskeletal Research Hub at the Charles Perkins Centre, The University of Sydney. “What’s exciting is that melatonin may also help manage chronic pain, opening the door to reducing reliance on medications that come with more risks.”

Importantly, the scientists also note the link between sleep quality and pain signals. So melatonin, for some, could offer a "two birds with one stone" treatment that is markedly safer than many other pain medications if taken properly.

“For many patients, pain doesn’t exist in isolation and is closely tied to poor sleep,” Wu says. “Melatonin appears to target both, which makes it particularly useful for people managing chronic pain.”

Again, there wasn't a one-size-fits-all treatment, according to the studies.

For chronic musculoskeletal pain, doses between 3 mg and 10 mg were effective, with 3 mg per day being most common. For postoperative pain, it was 1 mg to 10 mg, with 5-6 mg per day appearing to be the sweet spot.

And the supplement was mostly taken within a one-hour window of bedtime.

However, the researchers did not find a meaningful dose-response relationship, which opens the door to further studies that target specific pain conditions.

While we don't fully understand the potential mechanisms at play, beyond sleep quality as a factor, the study highlights the importance of investigating existing supplements and medications for use in treating different conditions.

“We’re taking a medication we already understand and applying it to a problem that affects a huge proportion of the global population,” says co-author Professor Paulo Ferreira, Director of the Musculoskeletal Research Hub at The University of Sydney.

Nonetheless, while melatonin is considered safe for use over a period of three months, the researchers stress the importance of consulting healthcare professionals before changing your pain-management regimen.

“Our advice isn’t for melatonin to replace every pain medication,” Wu adds. “Instead, after consultation with a doctor, it may be used as an adjunct to existing treatments, particularly for people who also experience sleep problems.

“The level of pain relief we observed is comparable to some conventional treatments, but this does not mean melatonin should replace them,” he continues. “Rather, it may offer a safer additional option within a broader pain management plan.”

The study was published in the journal PAIN.

Source: The University of Sydney via EurekAlert!

Fact-checked by Mike McRae

Editor's note: This story was originally published on our dedicated Health & Science site Refractor.io a week ago.