In the acidic environment of the stomach, I3C undergoes acid-catalyzed condensation to form DIM (~10-20% of I3C converts), ICZ (indolo[3,2-b]carbazole, a potent AhR agonist), and other condensation products. DIM modulates estrogen metabolism by: (1) inducing CYP1A1/1A2 (Phase I enzymes that produce protective 2-OHE1) and suppressing CYP1B1 (which produces genotoxic 4-OHE1); (2) acting as an androgen receptor antagonist at high concentrations; (3) inhibiting NF-κB. The concern: ICZ is a potent aryl hydrocarbon receptor (AhR) agonist, the same receptor activated by dioxin, raising theoretical long-term safety questions that DIM supplementation avoids.
Independently graded against 178,763 indexed supplements and 757 reviewed supplement and medication pairs, sourced from PubMed, FDA CAERS, openFDA, and NIH DSLD | Last updated:
Not medical advice. Based on published clinical research and systematic reviews.