This Super-Common Supplement May Harm Gut Health, Study Suggests

Odds are you know someone who's reached for melatonin to help them sleep better, and that person might even be you. The hormone is naturally produced in the body, yet it's become one of the most widely used (and unregulated) supplements out there.

And according to research published in the journal Microorganisms1, you may want to curb your melatonin habit for the sake of your gut health, especially if you have inflammatory bowel disease (IBD). Here's what the study found.

Does melatonin make inflammatory bowel disease worse?

For this study, researchers wanted to investigate the connections between IBD, supplementing melatonin, and the subsequent immune responses and bacterial compositions in the guts of mice. To do so, they created a mouse model of IBD, administering melatonin to a portion of them.

Based on their analysis, melatonin actually made symptoms and recovery worse for the mice who had been administered melatonin, showing worsened gut inflammation and during remission, slower recovery.

Namely, the mice who had been administered melatonin showed notable signs of colitis aggravation, delayed recovery, and increased inflammatory markers, which the study authors say confirm the harmful effects of melatonin supplementation on a disrupted gut barrier.

While these findings have yet to be replicated in humans, study co-author and immunologist Cristina Ribeiro de Barros Cardoso, Ph.D., notes that people should be scrutinous when it comes to hormonal supplements.

"Our study shows that people should be careful about taking hormone supplements and that the ingestion of melatonin as a supplement can have adverse effects on health," she says in a news release, adding, "[Melatonin is] a hormone, and regulation of the interaction between all hormones and the immune system is very delicate."

What to do about it

Even if you don't have IBD, these findings raise some interesting questions about the relationship between melatonin, the gut, and the immune system, suggesting that if you can avoid melatonin, it might be in your best interest.

You might opt for some lifestyle modifications instead, like forgoing screens late at night and going to bed at the same time each day.

If you do want to get the benefits of a great night's sleep without taking any hormones, we recommend a quality, nonhormonal, non-habit-forming supplement for sleep that's made with research-backed ingredients like magnesium (an essential mineral that is not a hormone).

The takeaway

It seems like more and more people are taking melatonin despite more and more research coming out that it is not a magic pill for sleep.