well if you know that you are prone to gyno and taking steroids that can increase estrogen easily such as test and dbol then start using anti-e's from the start. for myself not being very prone i would just have it in case i start to see my nips get puffy, itchy, sore. anastrozole works well and helps out bloat fairly well, but if not taking high dosages then nolvs 20-40mg should work just fine.