When it comes to Melatonin the problem is that people take way too much. Anything over 5mg would make me groggy too, and they come in as high as 10mg caps.
What I do is I buy the 5mg caps and I snap them into 4 quarters. I take one sublingual at bedtime, and when I'm up to piss if I can't fall back asleep easily I'll take another.
No grogginess as its low dose and spread out.
I hear you.. I used to take melatonin all the time and I did fine.. loved the sleep from it.. But I realize those were 3mg pills.. the ones the wife gets are 5mg.. and I see she bought a box of 10mg the other day. WIfe uses them no problems.
Maybe I'll try 1/2 tonight.