I love Primo, takes a lot of time but you make clean and steady gains. Love it! I take a vial of Primo with me as plushie when going to bed.Then I must have some super Primo. Strenth, size, and the only negative for me is I have to run high test with it and get oily skin. As far as I can tell Mast is for ladies. Admittedly, I have never went over 400mg Mast so that might be the problem. Or maybe because I'm 17% body fat I cant notice the gains. lol

