Too much. 3-5mg. Too much melatonin has the opposite effect.

I was a terrible sleeper and absolutely drank to get tired for a long time. It ain’t good sleep but you already know that. I seitched booze for kratom a couple years back, one cup a night, and then I read in bed, take melatonin, and 15-30m to fall asleep most nights, for the first time in my life (except when I was in the service, but it’s easy to sleep when you’re physically exhausted often). I’m 38 now. It’s good.