What is melatonin

Last updated: April 1, 2026

Quick Answer: Melatonin is a hormone produced by the pineal gland in the brain that regulates sleep-wake cycles and circadian rhythms. It's also available as a dietary supplement used to treat sleep disorders and jet lag.

Key Facts

What is Melatonin

Melatonin is a naturally occurring hormone produced by the pineal gland, a small gland located deep within the brain. The primary function of melatonin is to regulate the body's circadian rhythm, which is the internal clock that controls the sleep-wake cycle. When evening approaches and daylight decreases, the pineal gland produces melatonin, signaling to the body that it's time to sleep.

How Melatonin Works

Melatonin works by binding to receptors in the brain and body that regulate sleep and wakefulness. It doesn't directly cause sleep but rather facilitates the body's natural ability to fall asleep by lowering body temperature and promoting relaxation. Light exposure suppresses melatonin production—this is why bright light from screens can interfere with sleep. The body's melatonin levels typically peak around 2-4 AM and are lowest during daylight hours.

Functions Beyond Sleep

While melatonin is primarily known for sleep regulation, it has other important functions in the body:

Melatonin Supplements

Melatonin supplements are available over-the-counter and are used to address various sleep issues. They're particularly useful for jet lag, shift work sleep disorders, and insomnia. Unlike prescription sleep medications, melatonin is generally considered safe with few side effects, though effectiveness varies between individuals. Typical doses range from 0.5 to 5 mg, though some people use higher doses.

Age and Melatonin Levels

Melatonin production naturally decreases with age, which is why many older adults experience sleep difficulties. Children typically have higher melatonin levels than adults. This age-related decline is one reason why sleep problems become more common later in life, and why melatonin supplements may be particularly helpful for older individuals.

Related Questions

Is melatonin safe to take every night?

Short-term melatonin use is generally safe for most people, but long-term daily use hasn't been extensively studied. It's best to use melatonin as a short-term solution and to consult with a healthcare provider about extended use, as individual responses vary.

Can melatonin help with jet lag?

Yes, melatonin is effective for managing jet lag when taken at the appropriate time. Taking melatonin in the evening at your destination helps reset your circadian rhythm more quickly than natural light exposure alone, though timing is important for maximum effectiveness.

What's the difference between natural melatonin and supplements?

Natural melatonin is produced by your body's pineal gland in response to darkness, while supplements provide a synthetic or extracted form of the hormone. Supplements can help when natural production is low, but they don't create melatonin—they just supplement what your body already makes.

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Sources

  1. Wikipedia - Melatonin CC-BY-SA-4.0
  2. National Center for Complementary and Integrative Health - Melatonin Public Domain