Melatonin and Weight: What’s the Connection?

If it seems harder than ever for you to fall asleep, you aren’t alone. More people than ever are turning to melatonin supplements to try to sleep—and for many of them, it’s a game changer.

Of course, it only takes one person one time on one website to start asking, “Can taking this medication make you gain weight?” for misinformation to start spreading. Melatonin is no exception, as people on social media have begun attributing the supplement to weight gain and even insulin resistance.

We have some good news—there’s no clinical evidence that melatonin supplements will make you gain weight. Now that that’s out of the way, pardon us while we dig into some science to vindicate melatonin.

What is melatonin?
Melatonin is a naturally occurring antioxidant hormone in the body. It is released primarily by our brains. Melatonin is most well-known for serving as our internal biological clock (aka circadian rhythm). The hormone goes up at night, sending us to sleep, and drops in the morning when it is time to wake up. Melatonin falls naturally with age, which may be a reason it's harder to sleep as you get older.

Melatonin is also connected to metabolism. The hormone is related to insulin, which tends to be highest during the day when melatonin is at its lowest. It also appears that insulin resistance can lead to lower levels of melatonin Melatonin is also related to the stress hormone, cortisol, which we know may contribute to weight gain. 

Scientists are still figuring out exactly how our many hormones, including melatonin, affect each other—but it's clear that our bodies are more interconnected than we ever thought.

Does melatonin make you gain weight?
While melatonin has a connection with metabolism, there’s no evidence suggesting taking melatonin supplements will cause you to gain weight. But do you know what does cause weight gain? Not getting enough sleep.

Studies have shown that working the night shift may make you more vulnerable to metabolic syndrome, a catch-all term for a group of common health issues related to obesity (high blood pressure, high cholesterol, insulin resistance, high body fat percentage). That suggests that working against our circadian rhythms, regulated by melatonin, may contribute to obesity.

Not getting enough sleep can also contribute to stress, which we know can lead to weight gain. Additionally, not getting enough sleep can also knock your hunger hormones (and hunger signals) out of whack. 

Still, as with any medication or supplement, talk to your healthcare provider before taking any melatonin supplement, especially if you’re taking other medications or supplements. They'll help determine which ones may be harmful or helpful—or if there's something else going on with your health that needs further attention.

Melatonin alternatives

Melatonin is not the only supplement out there to promote sleep:

• Magnesium: An alternative supplement is magnesium, which has been shown to improve sleep and even—get this— increase melatonin, as shown in one study of older adults.
• Tea: Several types of tea promote sleep, including chamomile, valerian, and passionflower. Make sure to get a variety without caffeine.
• Tart cherry juice: This fruit juice packs a hefty dose of naturally occurring melatonin in every sip. Make yourself a sleepytime mocktail with tart cherry juice, club soda, and stevia. 

We hope this has eased any concerns about melatonin and weight gain. It can be easy to blame a specific supplement on anecdotal evidence, but we mustn’t miss the real connection between melatonin and weight: that getting enough sleep truly is key to losing weight.

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