As mentioned above, a person would have to be right on the edge of an estrogen problem anyway for a dosage such as 5 or 10 mg/day to cause an estrogen problem. So the answer would be generally no. But if for example already having small natural gyno, then it might make sense to avoid even very small increases in estrogen such as this would be. But it would not take a full 50 mg of Clomid to counteract 10 mg/day of Dianabol. One Clomid tab the first day, the second day, and then one per every three days (. days 5, 8, and so forth) should be plenty for that.