I3C (Indole-3-Carbinol) — Frequently Asked Questions
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Frequently Asked Questions
Should I take I3C or DIM?
Should I take I3C or DIM?
DIM is generally preferred for targeted estrogen metabolism support because it provides the primary active metabolite directly, with more predictable dosing and fewer GI side effects. I3C may be preferred when broader Phase I/II detoxification enzyme induction is desired, as it produces a wider range of metabolites beyond just DIM. Some practitioners recommend a combination of both.
How much broccoli would I need to eat to get a clinical dose of I3C?
How much broccoli would I need to eat to get a clinical dose of I3C?
You would need to eat approximately 1-2 pounds of raw cruciferous vegetables daily to obtain 200-400mg of I3C. Cooking reduces I3C content by 30-60%. Supplementation provides a far more practical and consistent dose than dietary intake alone.
Is I3C safe for long-term use?
Is I3C safe for long-term use?
Studies up to 12 weeks have shown I3C to be generally safe at doses up to 400mg daily. Long-term safety data beyond 12 weeks is limited. Some theoretical concerns exist about high-dose I3C promoting certain undesirable metabolites in the stomach. Periodic breaks or switching to DIM for long-term use is sometimes recommended by practitioners.
References
- Bell MC, Crowley-Nowick P, Bradlow HL, Sepkovic DW, Schmidt-Grimminger D, Howell P, Mayeaux EJ, Tucker A, Turbat-Herrera EA, Mathis JM (2000). Placebo-controlled trial of indole-3-carbinol in the treatment of CIN. Gynecologic Oncology. DOI PubMed
- Reed GA, Arneson DW, Putnam WC, Smith HJ, Gray JC, Sullivan DK, Mayo MS, Crowell JA, Hurwitz A (2005). Single-dose and multiple-dose administration of indole-3-carbinol to women: pharmacokinetics based on 3,3'-diindolylmethane. Cancer Epidemiology, Biomarkers & Prevention. DOI PubMed