I have been taking DIM 200 mg since January. In my opinion it does not do what an AI would do. If you need a little bump to get your slightly elevated estradiol down a few points then DIM is the supplement for you, but it won't bring it down 10 or more points. What it has done for me is the following:
1. At 400 mg it has taken away the cystic acne I was getting due to TRT
2. Typically when my estradiol is too high I get hot flashes, this keeps them in check
3. It's dropped my estradiol about 5 points, but never more than that.