Before jumping on a DIM + I3C estrogen management protocol/supplements, read the following article on safety about these supplements.
Based on this article (which references scientific studies), it would appear DIM is the safer choice.
Also, some more info on DIM: dimfaq.com
annieappleseedproject.org/dimsafin.html
Conclusion:
The I3C safety issues described here should not be lightly dismissed – every one of these safety concerns must be addressed by anyone advocating I3C. Animal and human testing raises the concern of I3C toxicity. Excessive enzyme induction, as seen with I3C, is associated with disease promotion.
In contrast, DIM has a consistently positive safety record which makes a strong argument for its safe, effective and long-term use in humans. For those interested in a scientifically-based, cruciferous supplement for estrogen-related concerns, DIM provides distinct advantages over I3C. DIM is a conservative, well-studied, safe, and clearly effective natural substance.