melatoninType: Hormone

Active ingredient: Melatonin (N-acetyl-5-methoxytryptamine)

Common use: Melatonin is commonly used as a sleep aid. In the United States, it is classified as a dietary supplement and not a medicine by the US Food and Drug Administration (FDA).

Melatonin is a substances found in both animals, plants, fungi and bacteria. In animals, including humans, melatonin is a hormone involved in the synchronization of the circadian rhythms of physiological functions such as sleep timing and blood pressure regulation. Melatonin is also a potent antioxidant that plays a role in the protection of nuclear and mitochondrial DNA.

How to use: Melatonin is available in capsules, tablets, liquid, sublingual spray and transdermal patches. Some preparations are prolonged-release and will release melatonin gradually over 8-10 hours to mimic the body’s own internal secretion of melatonin.

Melatonin is typically taken a few hours before bedtime in accordance with the phase response curve for melatonin in humans.

How to store: How to store the product depends on what type of product you have purchased (tablets, spray, patch, etc). Follow the recommendations from the manufacturer.


  • Consult a doctor before using melatonin, because it can cause negative side-effects when combined with certain disorders and/or medications.
  • Melatonin can cause nausea and irritability.
  • Using melatonin can cause drowsiness after sleeping.
  • Melatonin can lower FSH levels (the levels of follicle-stimulating hormone) but is not recommended as a contraceptive.
  • Anticoagulants are known to interact with melatonin.
  • In the elderly, melatonin can cause reduced blood flow and hypothermia.
  • There is conflicting evidence regarding melatonin’s effect on auto-immune disorders. Some studies indicate that melatonin exacerbate the symptoms while other studies indicate the opposite. Caution is warranted until more light has been shed on the situation.