Sustain Alpha is mostly a very pure form of Resveratrol. SA's main function is to increase LH ans FSH. Hyperdrol X2 is an aromatase inhibitor, probably the best OTC one you will find anywhere, and will lower estrogen significantly as well as raise testosterone. SA is good but for more immediate strength gains HX2 would be your best bet. Im a little over a week through a log of HX2 and I have noticed good strength gains already and am up about 2 lbs, nothin crazy, its not roidz but a def noticeable increase in strength and vascularity as well as intensity and aggression in the gym. I have not used SA but I have used other resveratrol products before and none of them compared to HX2.