A minor can buy melatonin as there's no legal minimum age to purchase melatonin, at least in the United States.
In the United States, unlike other medication, there is generally no legal minimum age that is required to purchase melatonin, as melatonin is classified as a dietary supplement rather than a prescription drug.
So while you can technically buy melatonin at most pharmacies or grocery stores, many retailers however may have internal policies or may ask for ID if a product is marketed as a sleep aid.
Outside the U.S., laws are much stricter; for example, in the UK, Australia, and parts of Europe, melatonin is prescription-only for all ages.
So while you don't legally have to have ID to buy melatonin in the United States, some stores might ask for ID for melatonin as it's used as a sleep aid.
But that is an individual stores policy and not a legal requirement.
The FDA does not regulate supplements like melatonin for purity.
And one study also had found that some melatonin gummies also contain around 478% more of the melatonin hormone than the label had claimed it had.
Melatonin is also a hormone that the body naturally produces and some people may not be producing enough of it or have a disruption in the melatonin production, which could be preventing them from sleeping.
So they take melatonin, which often helps and is much safer than other sleep aids.
Melatonin works very well, and is often taken 30 minutes before bed and I have found that it works very well for me as well.
My sleep quality and ability to sleep through the night has improved greatly after starting melatonin.