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Benefits of I3C (Indole-3-Carbinol)

Evidence:Moderate
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This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Evidence-Based Benefits

  • Estrogen metabolism — 400mg daily increased the 2:16-hydroxyestrone ratio by approximately 50% in a 12-week RCT (Bradlow et al., 1991; Reed et al., 2005)
  • Cervical health — 200-400mg daily promoted regression of CIN in a pilot study of 30 women over 12 weeks (Bell et al., 2000)
  • Detoxification support — I3C upregulates Phase I and Phase II liver detoxification enzymes (CYP1A1, GST)
  • Antioxidant activity — I3C metabolites demonstrate free radical scavenging in cell-based assays

What the Research Says

I3C has been studied for estrogen metabolism modulation since the early 1990s. Bradlow et al. first demonstrated its ability to shift estrogen metabolism toward 2-hydroxylation. A notable pilot study by Bell et al. (2000) in Gynecologic Oncology showed 50% regression of CIN 2-3 at 200-400mg daily over 12 weeks. However, the variable metabolite profile created during gastric acid conversion has led many practitioners to recommend DIM as a more predictable alternative.

Related Conditions

Hormonal Imbalance
Full I3C (Indole-3-Carbinol) Guide

References

  1. RCTBell 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
  2. RCTReed 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