zinc and magnesium are essential minerals required for human nutrition. if you were to injest zero zinc and magnesium, eventualy you would die.
what are you asking when you say does it work?
do you mean is zinc magnesium aspartate a good, bio-available form. the answer to that is yes.
are you referring to the 'notion' that ZMA increseas test? it is true that the mineral zinc is absolutely essential for the production of testosterone. without zinc you cant produce testosterone, so if you were ALREADY deficient in zinc, then ZMA would help. if you already have enough zinc in your diet then ZMA wont boost test.
many people think that certain vitmains and minerals are miracle cures. in reality they are just substances that are essential for normal body processes. if you are deficient in a particular vitmain or mineral, your functioning will be impaired. this impairment may manifest itself and appear as some kind of disease or illness. consuming the deficient vitamin or mineral will not cure the perceived illness, it will only restore you to normal funtion, since you really didnt have an illness, you had a deficiency