General Dosage
200-400mg I3C daily in divided doses
Maximum dose: 400mg daily; higher doses may cause GI side effects and unpredictable metabolite formation
Indole-3-Carbinol (I3C) Dosage Guide
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Dosage Recommendations
General recommendation: 200-400mg I3C daily in divided doses
Timing: With meals in divided doses (e.g., 200mg twice daily); stomach acid is needed for conversion to active metabolites • Take with food for best absorption.
Dosage by Condition
| Condition | Recommended Dose | Evidence |
|---|---|---|
| Estrogen metabolism modulation | 200-400mg daily in divided doses | Moderate |
| HPV-related papillomatosis | 200mg daily | Moderate |
| Cervical health (CIN) | 200-400mg daily | Emerging |
Upper limit: 400mg daily; higher doses may cause GI side effects and unpredictable metabolite formation
Timing & Absorption
With meals in divided doses (e.g., 200mg twice daily); stomach acid is needed for conversion to active metabolites
Best taken with food for optimal absorption.
References
- Rosen CA, Bryson PC (1998). Indole-3-carbinol for recurrent respiratory papillomatosis: long-term results. Journal of Voice. PubMed
- Bell MC, Crowley-Nowick P, Bradlow HL, et al. (2000). Placebo-controlled trial of indole-3-carbinol in the treatment of CIN. Gynecologic Oncology. DOI PubMed
- Reed GA, Arneson DW, Putnam WC, et al. (2006). Single-dose and multiple-dose administration of indole-3-carbinol to women: pharmacokinetics based on 3,3'-diindolylmethane. Cancer Epidemiology, Biomarkers & Prevention. DOI PubMed