Melatonin May Help You Sleep, But Will It Make You Gain Weight?

Melatonin is a hormone the body naturally produces to help us go to sleep (per Mayo Clinic). The body releases melatonin when it starts to get dark, but some people may need to rely on the supplement form for added help when circumstances such as being jet-lagged, battling insomnia, or dealing with other sleep disorders. Melatonin supplements are generally safe. Of course, it's always a good idea to talk to your doctor before using them — especially if you want to give them to a child.

Side effects such as headaches, dizziness, nausea, and drowsiness can happen if melatonin supplements aren't used properly. A 2019 study published in Complementary Therapies in Medicine also expresses concern caused by how taking too much might negatively impact other hormones. Another issue surfacing is that melatonin supplements might be contributing to weight gain, but it depends on what time you take it.

The relationship between melatonin and your metabolism

When melatonin is released, the body slows down functions like digestion and starts to repair, rest, and recover (per Mindbodygreen). By taking a melatonin supplement, your body gets a head start on this process. If you take a melatonin supplement too early in preparation for a good night's sleep, you're also slowing down your digestion earlier. As a result, your body might hold on to calories that it otherwise would be burning.

The good news is that this problem can easily be resolved by spacing out the time between dinner and when you take your melatonin supplement. Healthline recommends taking melatonin 30 to 60 minutes before you go to bed. Melatonin can live in your system for 5 hours and taking just 1 to 5 mg is considered the proper dosage. To find the right amount for you, it's a good idea to start with a low dose and, if needed, gradually increase based on how your body responds.