Can Melatonin Help You Sleep But Cause Weight Gain?

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 2024 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

Woman pinching belly fat

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.

Lesa O'Leary
Lesa O'Leary

Lesa is a dynamic member of OzHelp’s Service Delivery Team as the Service Delivery Team Leader and Nurse. She has been with OzHelp for five years and believes in leading by example. Lesa has experience in the not-for-profit sector, as well as many roles throughout different industries and sectors, including as a contractor to the Department of Defence. She has expertise in delivering OzHelp’s health and wellbeing programs and engaging with clients in a relaxed and comfortable manner that aligns with the organisation’s vision and objectives.

Lesa has a Certificate 4 in Nursing from Wodonga Tafe, Certificate 4 in Mental Health from Open Colleges, and is currently undertaking a Certificate 4 in Training and Assessment from Tafe NSW. For the past few months Lesa has been an Education and Memberships committee member of the ACT Branch of the National Association of Women in Construction (NAWIC).