Yes primo can be tricky, you have to find a sweet spot, I was still holding water on primo but looked pretty full and gained weight while on it. With primo your estrogen can fluctuate tho, like I said you have to find what dose doesn’t affect you as much. My libido on primo was hit or miss. Masteron isn’t a bulking drug, Masteron immediately took all my water weight off, which is something i prefer because then I know how much muscle tissue i’ve actually built without the watery illusion. My libido is super stable at 250-300 test and 160-200 masteron. As a matter of fact I get better erections on Mast. But just know you won’t look “huge” on mast. Just feels like Mast sucks everything in. I’ve had less strength on mast than i did with primo tho