How Long Does Melatonin Last in Your Body? Melatonin is fast-acting, with a half-life of 20 to 40 minutes. The half-life of a medication or supplement measures how long it takes for half the dose to be processed and eliminated by the body.

How long does melatonin take to wear off?

Melatonin takes between four to eight hours to wear off, but the amount of melatonin you take can cause this number to vary significantly. Generally, Buenaver suggests taking the lowest dose possible and advises starting at around one to three milligrams.

How many hours does melatonin make you sleep?

On average, melatonin takes effect within 30–60 minutes. OTC melatonin can stay in the body for 4–10 hours, depending on the dose and formulation. People should avoid taking melatonin at or after their intended bedtime. Doing so can shift their sleep-wake cycle and lead to daytime sleepiness.