I've used Nolva (20mg/day) and Deca only. 400mg/week (Denkall) and once Tt 600mg/week. I did not have any gyno problem. I think too many people are emphasizing Aridimex. Nolva binds at the estrogen receptor site of the breast -- i.e., competes against the effect of Estrogen. From what I know, Arimidex is an anti-aromatase. I would stay with Nolva always even if I were taking Arimidex.