What Is Melatonin’s Role in Weight Loss?

Melatonin and weight loss

Many people struggle to lose weight and there’s little doubt that hormones play a role. These include appetite hormones and sex hormone, such as estrogen. One that you hear less about is melatonin, a hormone produced by a tiny gland in your brain that rises when you sleep at night.

It’s the pineal gland, located deep within your brain, that produces melatonin. Melatonin helps control sleep cycles and your body’s natural circadian rhythms and has antioxidant properties. Your pineal gland produces melatonin in response to darkness, and when you wake up in the morning the melatonin production drop. Such cycling helps regulate your body’s natural rhythms.

As an antioxidant, melatonin reduces oxidative stress and prevents damage to cells. In fact, it’s one of the most powerful internal antioxidants. People sometimes take supplemental melatonin to help with insomnia and improve sleep quality. Some doctors also recommend it for jet lag when people fly across time zones. Jet lag disrupts your body’s internal clock, and melatonin helps reset it. Melatonin production also declines with age, which may explain why the elderly have a harder time sleeping at night.

Melatonin and Weight Loss: Is It Effective?

Some sources claim that melatonin helps with weight loss and weight control. Anecdotally, there is some support for this idea, but there’s no solid evidence or high-quality human studies showing that melatonin causes significant weight loss. Yet there are reasons why it may be beneficial if you’re trying to slim down.

Most studies showing the benefits of melatonin for weight loss are in animals. A study in rats found that supplementing rats with melatonin over six weeks increased the amount of beige fat the rodents carried on their frame. The study was randomized so some rats got melatonin and others didn’t. At the end of six weeks, the rats who drank melatonin-laced water accumulated more beige fat.

Why is this important? All fat is not created equal. Beige fat is more metabolically active than standard white fat, the storage form of fat. Having more beige fat means you burn more calories per day than if you have less. So, having more beige fat may give you a calorie-burning advantage. Studies also link low melatonin with worsening metabolic health and insulin resistance.

Sleep Matters for Appetite Control and Weight Loss

Since melatonin helps regulate the sleep-wake cycle, it aids in getting a good night’s sleep. Research shows that high-quality sleep is essential for appetite and weight control. Lack of sleep increases levels of the appetite hormone ghrelin, which boosts appetite and cravings for sugary foods. It’s easy to see how that would lead to weight gain. You eat more and make food selections that are less healthy after a night of poor sleep. Dieting itself can disrupt your sleep cycle, and melatonin may help prevent this.

The Role Lifestyle Plays in Melatonin Release

Your lifestyle habits affect how much melatonin your pineal gland releases. Melatonin release tends to go down with age, especially after the age of 60 and that can reduce sleep quality. According to SleepFoundation.org, melatonin can help you fall asleep seven to eight minutes faster. So, it may reduce the time you spend tossing and turning. We know that sleep is tied to the activity of appetite hormones and lack of sleep can make you hungry and cause you to make unhealthy food choices.

One way to support your body’s natural melatonin production is to expose your eyes to natural light during the day, preferably before noon. Throw open the curtains or blinds when you wake up and let natural light in. At night, stop using devices that emit blue light within two hours of bedtime. Blue light reduces melatonin release and makes it harder to sleep.

Diet, Melatonin, and Weight Loss

Some foods contain natural melatonin. For example, tart cherries are one of the best sources of natural melatonin to help with sleep, and there’s science to support it. A study found that drinking tart cherry juice increased melatonin and may improve sleep duration and quality. Some stores even sell tart cherry extract as a supplement for sleep.

Other good food sources of melatonin include walnuts, fennel, sunflower seeds, red bell peppers, eggs, goji berries, and milk. But it’s not clear whether you can get enough melatonin from food alone to have any benefit.

Does Exercise Increase Melatonin?

Exercise is a powerful tool in your weight-control toolbox, and it helps with weight loss and weight control through more than burning calories. There’s evidence that exercise can boost your melatonin level. However, the effects depend on the type, duration, and intensity of exercise. Morning and early afternoon exercise is the best way to support healthy sleep and melatonin release. The study showed that exercising late in the evening may reduce melatonin release. Plus, exercise helps you burn more calories and improve your body composition.

Taking an outdoor walk early in the day may also enhance melatonin release at night when you’re trying to sleep, as exposing your eyes to daylight properly sets your internal biological clock. So, light exposure during the day is positive while light at night, especially blue light, is not.

 The Bottom Line

There is evidence that melatonin may help with weight loss and weight control, at least indirectly. Maximize melatonin and your body’s natural circadian rhythms by getting outdoors into natural light during the day and sleeping in a dark room at night. Eating melatonin-rich foods may also have some benefits. But before taking a melatonin supplement, talk to your physician.


  • “Melatonin Dosage by Age and Weight | Sleep Foundation.” 01 Jun. 2021, sleepfoundation.org/melatonin/melatonin-dosage-how-much-should-you-take.
  • Howatson G, Bell PG, Tallent J, Middleton B, McHugh MP, Ellis J. Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. Eur J Nutr. 2012 Dec;51(8):909-16. doi: 10.1007/s00394-011-0263-7. Epub 2011 Oct 30. PMID: 22038497.
  • Buxton OM, L’Hermite-Balériaux M, Hirschfeld U, Cauter E. Acute and delayed effects of exercise on human melatonin secretion. J Biol Rhythms. 1997 Dec;12(6):568-74. doi: 10.1177/074873049701200611. PMID: 9406031.
  • com. “Foods High in Melatonin”
  • “Study Demonstrates Role Of Exercise In Modifying Melatonin ….” 03 Dec. 2005, sciencedaily.com/releases/2005/12/051202132144.htm.

Related Articles By Cathe:

5 Ways to Lose Weight by Changing Your Living Environment

5 Reasons, According to Science, That Men Lose Weight Faster Than Women

5 Ways Men and Women View Weight Loss Differently

Is It Easier for Men to Lose Weight?

Why Women Have More Problems Lowering Their Body Fat Than Men

What Role Does Estrogen Play in Muscle Strength?

5 Hormones and How They Affect Your Body Composition

Why Women Gain Weight After Menopause and How to Prevent It

Estrogen, Menopause, and Weight Gain: Is Estrogen a Friend or Foe for Maintaining a Healthy Body Composition?

Hi, I'm Cathe

I want to help you get in the best shape of your life and stay healthy with my workout videos, DVDs and Free Weekly Newsletter. Here are several ways you can watch and work out to my exercise videos and purchase my fitness products:

Get Your Free Weekly Cathe Friedrich Newsletter

Get free weekly tips on Fitness, Health, Weight Loss and Nutrition delivered directly to your email inbox. Plus get Special Cathe Product Offers and learn about What’s New at Cathe Dot Com.

Enter your email address below to start receiving my free weekly updates. Don’t worry…I guarantee 100% privacy. Your information will not be shared and you can easily unsubscribe whenever you like. Our Privacy Policy