Very relevant: https://slatestarcodex.com/2018/07/10/melatonin-much-more-th...

Some more interesting comments: https://www.lesswrong.com/posts/E4cKD9iTWHaE7f3AJ/melatonin-...

TL;DR:

- People take the wrong doses because pharmacies sell pills with huge doses, in reality 0.3 is optimal (can confirm from personal experimentation).

- People treat it like a sleeping pill when in reality it shifts the sleep cycle and it does so _depending on when you take it_. The article has various suggestions depending on your particular sleep issue.

If you use it, I suggest experimenting with the timing and dose, but especially timing - and I am talking multiple hours, up to 7, before going to sleep. And then do actually go to sleep immediately when you feel sleepy or it'll make you wake up too early and you'll be tired.