Zinc itself really isn't exactly worthless, but usually doesn't give any noticeable effect at all IMO. I tried ZMA when it first "came out" (lol, as if it was a breakthrough, 3 minerals!) and wasn't impessed at all. I have tried several times since then (post cycle also) and still have not noticed any measurable amount of difference. I won't say it doesn't entirely "work", but definitely just another extra couple bucks for me to throw away and pills to remember. The specific ratio of the minerals:
Vitamin B6: 10.5mg
Magnesium: 450mg
Zinc: 30mg
has been debated before, saying that only this ratio will provide results, and I find that hard to believe also. Maybe if you are deficient in zinc will it help raise natty test levels to a balance, but otherwise I don't place any value in it at all. But, if you choose to use this along with an anti-e of some sort, remember that you haven't standardized all the possible variables in the equation, so it cannot be said that ZMA was the direct contributor to a return of natty test levels.