I've taken DIM in the past and really felt it helped E2.. I don't have labs to confirm but my estrogen fat storage sites (chest, legs) became more lean.. in fact my chest was vascular and i was 15% body fat (so overall not lean)... anyway.. I don't think DIM would be a substitute for and Aromatase inhibitor (AI) for most people but might be able to help keep the amount of Aromatase inhibitor (AI) you take down. The whole thing is how would you know if it's working without before and after labs? You could take it and your regular dose of Aromatase inhibitor (AI) and if you started getting symptoms of low E, back off the Aromatase inhibitor (AI) a bit until you hit your sweet spot again, or of course test 4-6 weeks after starting it keeping your Aromatase inhibitor (AI) does the same. That's how i'd do it I think, in fact I might but I'd be starting both and Aromatase inhibitor (AI) and DIM together since i"m not on a Aromatase inhibitor (AI) yet. Good luck and keep this thread posted!