Melatonin is a naturally occurring hormone produced by the pineal gland in the brain. It plays a central role in regulating the body’s internal clock, also known as the circadian rhythm, which helps control sleep and wake cycles. In recent years, melatonin supplements have become one of the most commonly used sleep aids worldwide, particularly for individuals experiencing difficulty falling asleep, jet lag, or disruptions in their sleep schedule.

When used appropriately, melatonin supplementation may support healthy sleep onset and improve overall sleep timing. However, like any supplement, it should be used thoughtfully and as part of a broader approach to sleep health that includes consistent routines, proper sleep hygiene, and attention to lifestyle factors.

This guide provides evidence-based information about how melatonin works, who may benefit from supplementation, recommended dosages, potential side effects, and safe use considerations.

What Is Melatonin?

Melatonin is a hormone naturally released by the body in response to darkness. Its production increases in the evening, signaling to the body that it is time to prepare for sleep. Exposure to light — especially blue light from screens — can suppress melatonin production and delay sleep onset.

Melatonin does not “force” sleep in the same way that sedative medications do. Instead, it helps regulate the timing of sleep by reinforcing the body’s natural circadian rhythm. For this reason, melatonin is often described as a chronobiotic, meaning it helps adjust the timing of biological rhythms.

Melatonin levels typically:

• Rise in the evening
• Peak during the night
• Decline in the early morning

Disruptions in this pattern can occur due to:

• Shift work
• Jet lag
• Irregular sleep schedules
• Excessive evening light exposure
• Aging
• Stress
• Certain medical conditions

In these situations, supplemental melatonin may help restore a more consistent sleep-wake cycle.

How Melatonin Supports Sleep

Melatonin supports sleep primarily by helping the body recognize when it is time to sleep. It does not act as a sedative but instead helps coordinate the body’s internal timing signals.

Potential mechanisms include:

Regulation of Circadian Rhythm

Melatonin helps synchronize the sleep-wake cycle with environmental cues such as light and darkness. This is particularly important for individuals whose schedules shift frequently or who travel across time zones.

Support for Sleep Onset

Research suggests that melatonin supplementation may help reduce the time it takes to fall asleep, especially in individuals with delayed sleep phase syndrome or irregular sleep timing.

Adjustment to Time Zone Changes

Melatonin is commonly used to help manage jet lag by assisting the body in adapting to a new sleep schedule.

Support for Older Adults

Natural melatonin production tends to decline with age. Supplemental melatonin may help compensate for this reduction in some individuals.

Who May Benefit from Melatonin Supplementation

Melatonin supplementation may be helpful in specific situations where sleep timing is disrupted rather than when sleep problems are caused by other underlying medical conditions.

Common scenarios include:

Difficulty Falling Asleep

Individuals who take a long time to fall asleep may benefit from melatonin when sleep timing is misaligned with their natural circadian rhythm.

Jet Lag

Travel across multiple time zones can disrupt the body’s internal clock. Melatonin may help reduce symptoms such as fatigue and difficulty sleeping.

Shift Work

People who work night shifts or rotating schedules often experience irregular sleep patterns. Melatonin may help support sleep timing during daytime rest periods.

Delayed Sleep Phase Syndrome

This condition involves a consistent delay in sleep timing, often resulting in difficulty falling asleep until very late at night.

Age-Related Changes in Sleep

Older adults may produce less melatonin, which can contribute to changes in sleep patterns.