6 Oxo is used to kick in your testes to start making testosterone and is also supposed to be an anti-estrogen. Let me just make myself clear that I dont think 6 Oxo even comes close to the real stuff like Clomid, Nolvadex, etc. but in my experience, when I used 6 Oxo in the past....I did gain strength in the gym. To repeat one more time : It pales in comparison to the Clomid, Nolv, etc.