It won't do you much at your age howardalex. At least you asked! Good thing you didn't spend any money (regardles of how cheap it might've been)
You'll benefit better from taking Melatonin.
ZMA is just ZMA is a combio of zinc,maganesium and vitamin B6.
Supposedlyit gives you better rest but I wouldn't know cause I've never taken it
I wouldn't recommend it.