Melatonin is a hormone that helps you sleep well. A consequence of modern life is that the amount of melatonin your body makes, and when it makes it, is often different from how it used to be in the environment of our ancestors. Taking some extra melatonin before you go to sleep can ensure there is enough melatonin available in your body for you to sleep well.

The bottom line

Melatonin is safe^1,2 and cheap. The optimal dose is 0.3mg shortly before going to sleep². The reason much larger doses are available is patents² covering lower doses.

Other reliable sources are The Mayo Clinic³ and the NIH⁴.

References

1. 1. Evaluation of melatonin by Gwern Branwen
   2. Evaluation of melatonin by Scott Alexander
   3. The Mayo Clinic on melatonin
   4. The NIH on melatonin