March 21, 2017


Other name(s):

N-acetyl-5-methoxytryptamine, melanocyte-contracting principle, skin-lightening factor

General description

Melatonin is a hormone made by the pineal gland. This is a small endocrine gland at the base of the brain. Secretion of melatonin is controlled by exposure to light. Melatonin isn’t a nutrient.

Melatonin may play a part in the diurnal cycle. This is the regular cycle of wakefulness and sleep linked with day and night. Studies show above-average serum levels of melatonin in people with seasonal affective disorder (SAD). This is a type of depression. It’s linked with the short daylight hours in winter.

The pineal gland is the remainder of midline light receptors. It’s still found in some lower animals. It’s the tie to light that first indicated its job in the pineal gland. It also later found the link of melatonin to controlling the day-night wake and sleep cycle. Since that time, melatonin has been studied for its tie to the circadian rhythm and sleep.

Medically valid uses

Taking melatonin can shift the circadian (24-hour) clock by about one hour. This makes up for one hour of jet lag. But studies show that jet lag due to travel through more than two time zones cannot be quickly corrected by melatonin.

Unsubstantiated claims

Please note that this section reports on claims that have not yet been substantiated through studies.

Melatonin is said to help ease sleep disorders, such as insomnia. It may also help treat depression. It may also improve how the immune system works. Melatonin is also claimed to slow the aging process. It may even help manage some cancers when taken with other medicines.

Dosing format

Melatonin comes in both rapid-release and slow-release forms. The range being studied is 0.5–5 mg per day. A recommended amount hasn’t been set.

You should take melatonin two hours or less before your regular sleep time.

Women who are pregnant or breastfeeding should talk to their healthcare providers before taking any supplements.

Side effects, toxicity, and interactions

Melatonin may increase how often you have seizures if you have a certain type of seizure disorder.

Large doses of melatonin may get in the way of how the ovaries work. Melatonin has interfered with sexual development in animals who received the supplements.

You shouldn’t drive or use machinery for several hours after taking melatonin. The natural secretion of melatonin may be affected by several factors. These include stimulants, such as coffee, late night exercise, late night snacks, and light in the bedroom.

There are no known food or drug interactions with melatonin.




March 21, 2017


Physiology and clinical use of melatonin. UpToDate.

Reviewed By:  

Poulson, Brittany, RD, CDE,Wilkins, Joanna, R.D., C.D.