Melatonin is a natural hormone that regulates sleep. During daylight, the pineal gland in the brain produces an important neurotransmitter called serotonin. (A neurotransmitter is a chemical that relays messages between nerve cells.) But at night, the pineal gland stops producing serotonin and instead makes melatonin. This melatonin release helps trigger sleep.

The production of melatonin varies according to the amount of light you're exposed to; for example, your body produces more melatonin in a completely dark room than in a dimly lit one.

Melatonin supplements appear to be helpful for people whose natural sleep cycle has been disturbed, such as travelers suffering from jet lag. The hormone may also be helpful in various other sleep disorders.

Based on early reports that melatonin levels decline with age, the hormone was briefly marketed as a kind of fountain of youth. However, newer evidence suggests that melatonin levels do not decline with age after all.65

Other potential benefits of melatonin remain largely speculative. Very weak evidence hints that melatonin might be helpful for functional dyspepsia(chronic indigestion of unknown cause).113

Melatonin is not a nutrient. However, travelers and workers on rotating or late shifts can experience sleep disturbances that seem to be caused by changing melatonin levels.

You can boost your melatonin production naturally by getting thicker blinds for the bedroom windows or wearing a night mask. You can also take melatonin tablets.