A lot of people are affected by sleep disorders.

Although it is a common problem, poor sleep can have serious consequences.

Poor sleep can deplete your energy, lower your productivity, and increase your risk of diseases such as high blood pressure and diabetes (Study 1 ).

Melatonin is a hormone that tells your body when it's time to go to bed.

This article explains how melatonin works and how much to consume.

Melatonin is a hormone naturally produced by the body.

It is produced by the pineal gland in the brain, but also in other areas such as the eyes, bone marrow and intestines (Study 2 , 3 ).

It is often referred to as the "sleep hormone" because high levels can help you fall asleep.

However, melatonin itself will not directly put you to sleep. It simply lets your body know it's nighttime so you can relax and fall asleep more easily (Study 4 ).

Melatonin supplements are popular among people struggling with insomnia and jet lag. You can get it without a prescription in many countries.

Melatonin is also a powerful antioxidant that can provide a variety of other benefits.

It can even help support eye health, treat stomach ulcers and heartburn, relieve tinnitus symptoms, and even increase growth hormone levels in men.

Melatonin works with your body's circadian rhythm .

In simple words, circadian rhythm is your body's internal clock. They know when it's time to sleep, wake up and eat.

Melatonin also helps regulate body temperature, blood pressure, and hormone levels (Study 5 , 6 ).

Melatonin levels increase in your body when it's dark outside, signaling your body that it's time to sleep (Study 7 ).

It also binds to receptors in the body and can help you relax. For example, melatonin binds to receptors in the brain to reduce nerve activity. In the eyes, it may help reduce levels of dopamine, a hormone that helps you stay awake (Study 8 , 9 , 10 ).

Although the exact way melatonin helps you fall asleep is unclear, there is evidence that these processes can help you fall asleep .

Conversely, light suppresses melatonin production. This way, your body knows it's time to wake up (Study 11 ).

Because melatonin helps your body prepare for sleep, people who don't get enough of it at night may find it difficult to fall asleep.

There are many factors that can cause low levels at night. Stress, smoking, too much light at night (including blue light), too little daylight during the day, shift work and aging affect melatonin production (Study 12 , 13 , 14 , 15 ).

Taking a melatonin supplement can help compensate for low levels and normalize the internal clock.

Taking melatonin before bed has been shown to help you fall asleep (Study 16 , 17 , 18 , 19 ).

In an analysis of 19 studies of people with sleep disorders, scientists found that melatonin shortened the time it takes to fall asleep by an average of 7 minutes.

In many of these studies, people also reported significantly better sleep quality (Study 19 ).

Melatonin can also help with jet lag , a temporary sleep disorder.

Jet lag occurs when your body's internal clock is out of sync with the new time zone. Shift workers may also experience jet lag symptoms because they work during a time that would normally be scheduled for sleep (Study 20 ).

Melatonin may help reduce jet lag by synchronizing your internal clock with the time change (Study 21 ).

For example, an analysis of 10 studies examined the effects of melatonin in people who crossed five or more time zones. The scientists found that melatonin is remarkably effective at reducing the effects of jet lag.

The analysis also found that both lower doses (0.5 mg) and higher doses (5 mg) were equally effective in reducing jet lag (Study 22 ).