What is melatonin?

Melatonin is a hormone that your brain produces in response to darkness. It helps with the timing of your circadian rhythms (24-hour internal clock) and with sleep. Being exposed to light at night can block melatonin production.

Research suggests that melatonin plays other important roles in the body beyond sleep. However, these effects are not fully understood.

Melatonin dietary supplements can be made from animals or microorganisms, but most often they’re made synthetically. The information below is about melatonin dietary supplements.

How does melatonin work?

Melatonin works in tandem with your body’s circadian rhythm, aka your body’s internal clock. It lets you know when it’s time to sleep, wake up, and eat. Melatonin also helps regulate your body temperature, blood pressure, blood glucose, body weight, and levels of some hormones

Your melatonin levels start to rise when it’s dark outside, signaling to your body that it’s time to sleep. They then decrease in the morning, when it’s light outside, to promote wakefulness

Melatonin also binds to receptors in your body to help you relax. For instance, it binds to receptors in your brain to reduce nerve activity. It can also reduce levels of dopamine, a hormone that helps you stay awake, and is involved in some aspects of the day-night cycle of your eyes. Although melatonin’s exact mechanisms are unclear, research suggests that these processes may help you fall asleep.

Conversely, daylight modulates melatonin production, which is one way your body knows it’s time to wake up. Because melatonin helps your body prepare for sleep, people who don’t make enough of it at night can have trouble falling asleep.

Many factors may cause low melatonin levels at night, such as alcohol consumption, smoking, caffeine consumption, shift work, aging, certain medications, and exposure to too much light at night — including blue light.

What are the health benefits of taking melatonin?

Melatonin supplements may help with certain conditions, such as jet lag, delayed sleep-wake phase disorder, some sleep disorders in children, and anxiety before and after surgery.