I've never used anything from a doctor. Years ago I tried otc melatonin in the 1 mg tablet size - wow they worked. But now I can't find them anymore, but what I do find are tabs in the 300 'mcg' size which I never understood the unit of measurement until recently. 1000 mcg=1 mg. So, 3 300 mcg tabs = .9 mg.
4-5 of these things (300 mcg) work for me ok. 6 like last night, and I get really woozy - dizzy. I'm a big guy at 200 lbs and it works fine! helps so much to shut down the insane asylum upstairs!
But that's not to say that you should do what I do. You could hurt yourself if you're not used to it, or understand the effects that it could have on you. It's a natural substance and not prescription so, I'd say give it a shot. It may help, it may not. Just use caution and do not even think about driving or doing anything besides laying down afterwards.