I took havoc back in my junior year of highschool, i was inexperienced and went into my cycle not fully understanding how to run the cycle properly. I took novadex xt as my PCT and still suffered from a little gyno. id like to say that maybe 10 other athletes in my school suffered from gyno as well due to Havoc, so from first hand experience i am saying it can cause gyno so run your PCT on point and do not mess around like i did. On the other hand Havoc is a great product i gained 18 pounds from it and my strength increase was ridiculous. I was 5'7 weighing 150 and maxing out on bench at 185 before my cycle and around the third week i was able to put up 245 twice clean and was weighing 165. Durring my PCT i did lose some strength but all my size gains stayed.