Would definitely concur, and add that it's frustratingly hard to find small pills of melatonin.

I remember going to a presentation where the presenter was describing a clinical trial they were performing where they gave melatonin to some people for some reason I can't remember. But when they mentioned that they were giving 20mg each night the presenter noticed the look of absolute horror on my face. I almost asked them whether they wanted the participants to wake up again the next day.

I used to take half a milligram nightly, and did for about ten years. Recently I have been so exhausted all the time that I no longer have any trouble getting to sleep. Also, I think my body clock has changed now that I'm ten years older, because it does. I slept better when I stopped taking it, even though I definitely found it useful for a long time.