That's why I'm asking. I have read that a lot of girls use anti estrogenic the last 2-3 weeks of a cycle cause estrogen in a woman according to its functions also prevents women from build muscle and lose fat. That's why I was wondering. Thank you. 1  LVL2. 2  162. 3  littletigar24. 4  2 weeks ago. @ 5 LeanBodyMiss.