1-Andro is a two-step conversion to 1-Testosterone, doesn't have the sides of regular Testosterone, and is known for really small size/weight gain, but pretty dang good strength gains. The 4-AD is a two-step to Testosterone, and used to keep lethargy from 1-Andro away. I had physiological signs of raised T, but did not do blood work this last run. But if you look at my poundage increase, you can see strength going up pretty good for an old ass guy like me (almost 50). That was fine for my goals, so I'm happy. But like others have mentioned, there are a lot stronger, more cost effective compounds out there - but they may not be legal now, or hard to find.