ZMA doesn’t really help me fall asleep. It may increase dream activity, and honestly, I do feel better in the morning if I’ve been dreaming. Maybe its just a sign of a certain level of sleep, or maybe I resolve some stress during dreams. LOW magnesium can certainly do things that hurt sleep. LOW zinc can lower testosterone and so can poor sleep but I don’t know if ZMA supplements actually claim to have been demonstrated to improve sleep.
But you do need Zinc and Magnesium, and ZMA from Biotest is the only zinc supplement that I have used that doesn’t give me nausea and nausea before bed can certainly make it hard to go to sleep. So in summary I recommend Biotest ZMA as a zinc and magnesium supplement but I don’t recommend multi-vitamins because they don’t contain a proper balance of nutrients and tend to provide too much of some to get enough of others.
My wife has had magnesium deficient patients who have used high doses of magnesium for 3-5 days and basically if got rid of borderline depression symptoms and fibromyalgia, but I would want to use a straight magnesium source for that. B vitamins can sometimes have a calming effect that helps sleep, but I don’t remember which B vitamin does most of the good.