N-acetyl-5-methoxytryptamine, melanocyte-contracting principle, skin-lightening factor
Melatonin is a hormone made by the pineal gland. The pineal gland is a small neuroendocrine gland at the base of the brain. It makes and secretes melatonin. The secretion of melatonin is controlled by exposure to light. Melatonin isn’t a nutrient.
Melatonin may be a part of the diurnal cycle. This is also known as the circadian rhythm. 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 natural secretion of melatonin may be affected by:
- Stimulants, such as coffee
- Late night exercise
- Late night snacks
- Light in the bedroom
Medically valid uses
Taking melatonin can shift the circadian (24-hour) clock by about 1 hour. This makes up for 1 hour of jet lag. But studies show that jet lag due to travel through more than 2 time zones cannot be quickly corrected by melatonin.
There may be benefits that have not yet been proven through research.
Melatonin may help ease sleep disorders, such as insomnia. It may also help treat depression. It may improve how the immune system works. Melatonin may help to slow the aging process. It may help manage some cancers when taken with other medicines.
Melatonin comes in both rapid-release and slow-release forms. The range being studied is 0.5 mg to 5 mg per day. A recommended amount hasn’t been set.
You should take melatonin 2 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
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 large tools for several hours after taking melatonin. This is because it makes you sleepy.
There are no known food or medicine interactions with melatonin.
January 30, 2019
Physiology and clinical use of melatonin. UpToDate.
Diane Horowitz MD,Rita Sather RN,Raymond Kent Turley BSN MSN RN