Does Melatonin Help You Sleep? What the Data Shows

Melatonin is one of the most widely used sleep supplements, but does it actually improve your sleep? We analyzed WHOOP member data to quantify its real-world impact on sleep duration, sleep stages, and next-day Recovery. Beyond the numbers, we'll explore what melatonin is, how it works in your body, when to consider using it, and what you need to know about safety and long-term use.

What is melatonin?

Often referred to as the "sleep hormone," melatonin is produced naturally in a part of the brain called the pineal gland. Its purpose is to aid the regulation of your sleep cycle and circadian rhythm. Your melatonin levels are normally linked to the amount of light around you.

When the sun goes down, the pineal gland begins releasing more melatonin to let your body know it's time to go to sleep. In the morning melatonin production slows down, helping you to wake up. Melatonin is generally available as an over-the-counter supplement, typically a tablet or capsule that you take orally.

How does melatonin work for sleep?

Studies estimate that about 33% of adults worldwide may suffer from insomnia. While most people's bodies generate sufficient amounts of the hormone on their own, taking additional melatonin supplements can be useful for many of us who struggle to fall asleep. Although taking melatonin before bed won't help you stay asleep, it is often beneficial in enabling you to fall asleep faster.

Melatonin itself does not actually put you to sleep—it simply alerts your body to the fact that it's nighttime so it can get to sleep more easily. It does this by binding with receptors in your body and brain to better allow you to relax and decrease nerve activity. Melatonin may also reduce your levels of dopamine, a hormone associated with wakefulness.

What the data shows about melatonin and sleep

To better quantify the benefits of melatonin, we examined WHOOP members' sleep and recovery data when they report taking it. On average, WHOOP members get 34 more minutes of sleep each night when they take melatonin. They also average 2% more REM sleep (the mentally restorative stage of sleep) and wake up the next day with an 11% higher recovery.

On average, taking melatonin positively affects WHOOP members' sleep and recovery.

Our analysis controlled for other sleep-promoting behaviors (like blue-light blocking glasses, an eye mask, or reading before bed) that you might also try when taking melatonin. We found these numbers were consistent for both men and women, however the benefits of melatonin on both sleep time and recovery diminished with age.

When to consider taking melatonin

A standard recommendation for the best time to take melatonin is about 1-2 hours before you plan to go to sleep. Melatonin can often be useful in remedying the following common situations:

• Insomnia. Melatonin may decrease the length of time it takes you to fall asleep and improve your sleep efficiency.
• Jet lag. Taking melatonin for a few days prior to your new bedtime when you change time zones can help adjust your circadian rhythm and decrease jet lag symptoms.
• Shift work disorder. When you work night shifts and your sleep schedule does not align with sunrise and sunset, melatonin encourages your body to think it's dark outside even when it's not.

Safety, side effects, and long-term use

For most people, taking melatonin for short periods is generally considered safe. However, according to the National Institutes of Health, the effects of long-term, nightly use are less clear. Like any supplement, your body can adapt, and you might find it becomes less effective if you rely on it too heavily.

Recommended doses are typically low, often 1 milligram or less. Taking too much can lead to side effects like dizziness, headaches, nausea, diarrhea, joint pain, anxiety, and irritability. Because melatonin can interact with other medications or health conditions, consult your doctor before making it a regular part of your routine.

Measure the impact of melatonin with WHOOP

The data suggests melatonin can be a useful tool for improving sleep, but its effects are not universal. The only way to know for sure how it impacts your body is to measure it. The WHOOP Journal lets you log melatonin use and see its direct effect on your Sleep data and next-day Recovery.

Combined with validated, high-precision sleep tracking, WHOOP uses this data to provide you with actionable insights regarding which behaviors are most beneficial to your sleep and recovery. By analyzing your personal data, you can move from guessing to knowing, and make smarter decisions about your health.

Frequently asked questions about melatonin

Does melatonin help you stay asleep or just fall asleep?

Melatonin primarily helps with sleep onset—the process of falling asleep. It signals to your body that it's time to rest, which can shorten the time it takes you to fall asleep. It is generally less effective for sleep maintenance, or staying asleep throughout the night.

How long does it take for melatonin to work?

Melatonin typically begins to take effect within 1-2 hours. For this reason, it's best to take it about one to two hours before your intended bedtime to align its effects with your natural sleep-wake cycle.

What happens if you take melatonin every night?

While melatonin is considered safe for short-term use, the effects of taking it every night over a long period are not well-researched. Some individuals may find its effectiveness decreases with consistent use. For guidance on long-term use, it is always best to speak with a healthcare provider.