Melatonin typically takes about 1 to 2 hours to start working after it is taken.

How melatonin works

Melatonin is a natural hormone produced by the brain's pineal gland that helps to regulate the sleep-wake cycle. When taken as a supplement, it adds to the body's natural supply and promotes sleepiness by acting on receptors in the body that encourage sleep.

Onset time for melatonin supplements

• Generally, melatonin supplements begin to take effect within 20 to 40 minutes, depending on the formulation and dose, but it is commonly said to take around 1 to 2 hours to work fully.

• Extended-release forms of melatonin release the hormone more slowly and may take longer to reach peak levels in the bloodstream.

Thus, if someone takes melatonin, they can expect to feel its effects starting roughly within half an hour and more fully within 1 to 2 hours.