People looking for over the counter sleep aids often find melatonin along side other supplements. Since it is easily available, considered a supplement and not a medicine, there is plenty of incentive to at least try it. There are dozens of melatonin products on the market, freely available at supermarkets, pharmacies, health food stores and online. People take it in increasing doses (I have known people to take as much as 15 mg in one night), combine it with Benadryl products or alcohol, with various vitamins and in combination with various herbal preparations. It may make you briefly drowsy. It may seem to help you fall asleep for a few days. Unfortunately, that's about it. So what about the magic?
The magic wand you need to unleash the powerful magic of melatonin is to know the science behind what the substance is and how it works, and most importantly what it works for. Melatonin works fantastically well for people with "delayed sleep phase syndrome", a medical term describing the inability to fall asleep at a socially acceptable time and wake up at a socially acceptable time in order to be productive. It is a very common sleep problem often misdiagnosed as insomnia. It is more common in adolescents, and in creative people, musicians and artists; and often runs in families.
These people are fully capable of getting sufficient sleep but end up not getting enough because they don't get sleepy until later in the night and have to wake up early to go to school or work. If they could sleep in every day and work started later in the day they would be fine.
If melatonin is taken in the smallest amount available, it works best. Take more and you will likely be groggy when you wake up. It should be taken no earlier than 8 hours after naturally waking up, and about an hour before intended bed time. The product has to come from a reliable manufacturer since no one is effectively regulating the quality of the product.
Most of all, if you expose yourself to bright sources of light after taking melatonin you will cancel out its effects. These bright sources include all kinds of handheld and electronic device screens that emit light. Its effect will also be reduced if you activate your mind, get busy thinking, worrying or performing mental tasks.
Lots of caveats, true. But the potion's magic has the potential to change countless lives, provided it is used properly, with wisdom and knowledge. It is typically inexpensive and works much better than sleeping pills, for the person with "delayed sleep phase". For everyone else, unless your sleep physician specifically recommended it, you are probably wasting your money.