Melatonin generally starts to work within about 20 minutes to 1 hour after taking it, with most people feeling drowsy around 1 to 2 hours after ingestion. The body absorbs melatonin quickly, and blood levels tend to peak about an hour after taking a supplement. Extended-release forms of melatonin take longer to reach peak levels and work over a longer duration. It's typically recommended to take melatonin 30 minutes to 2 hours before bedtime to align with its onset of action so it can effectively help with sleep onset.
