[Traubenfuchs]

Because it doesn't do much. The extremely incorrect overdoses of it found in common products often lead to worse sleep and next day drowsiness, making it an unpleasant experience. Even used in correct, very low dosages the impact is low.

https://www.lesswrong.com/posts/E4cKD9iTWHaE7f3AJ/melatonin-...