This is exactly why. If you are the one person that can go full blast and have estrogen not raise, then sure, don't use an AI. But for 99.99999% of all people, estrogen will rise when cycle doses of test are used. So am AI should ALWAYS be used. Now if you're only talking about testosterone replacement, then you have a point. I don't use an AI for that because I domt need one. But if I use an extra 50mgs a week over my trt dose, my estrogen skyrockets. Estrogen, I've been told, is the most carcinogenic agent that can be introduced to a man's body. That says a lot when you compare that to smoking, drinking, asbestos, and other known carcinogens.