Ph D Nutrition ZMA 90 Caps Benefits Optimises natural hormone levels Deeper sleep when taken before sleep Increased recovery Helps improve performance Predator Nutrition ZMA 90 Caps Review Ph D Nutrition's ZMA helps correct what is likely to be a deficiency in zinc & magnesium for most people. Ph D's ZMA uses a relatively less well absorbed form of magnesium which may put some people off but providing you dose it accurately this will still deliver the benefits most people have come to enjoy from ZMA supplementation, namely enhanced sleep quality & better recovery from exercise.