Indole-3-Carbinol / DIM
I3C/DIM favors 2-OH estrogen (CYP1A1 ↑), curbs NF-κB/AhR for apoptosis/cell arrest, ↓ ER-α/AR in hormone cancers. Human biomarkers strong in breast/prostate/cervical; 200–400 mg PO safe—monitor hormones/CYP; adjunct for ER+ settings.
Forms: Oral capsules (supplement, 200–400 mg)
Key Takeaway
Cruciferous compound pair that shifts estrogen metabolism toward 2-OH pathways, induces CYP1A1, and can trigger apoptosis; useful adjunct in hormone-sensitive settings with emerging human data.
Evidence at a glance
Moderate clinical (biomarker/early trials) + robust preclinical; RCTs for efficacy pending.
How it may work
Indole-3-carbinol (I3C) and its metabolite diindolylmethane (DIM) shift estrogen metabolism toward the protective 2-hydroxyestrone (2-OH) pathway by inducing CYP1A1 and other phase I enzymes, reducing estrogen-driven carcinogenesis. They inhibit NF-κB and AhR signaling, inducing apoptosis and cell cycle arrest in cancer cells. I3C/DIM also suppress hormone-sensitive tumor growth by downregulating ER-α and modulating androgen receptors. Preclinical and human studies show efficacy in breast, prostate, and cervical cancers.
Targets & pathways
Curated mechanistic targets reported for this agent — how it may act on cells, not proof of a clinical effect.
Often studied / combined with
Combinations reported in the literature, not a protocol or a recommendation.
- Tamoxifen / Endocrine therapy: ER-α co-suppression in breast.
Overlapping mechanisms
- Estrogen Mod / CYP1A1 ↑ / Apoptosis ↑: Avoid excess with other AhR/CYP/estrogen agents; risk hormone imbalance without gain.
Safety & interactions
Severity and how well-established each signal is are shown separately. Verify everything with your oncologist or pharmacist — absence here does not mean safe.
- Endocrine therapies (e.g., tamoxifen)MonitorModerateTheoreticalAdditive estrogen modulation; hormone assays.
- CYP1A2 substrates (e.g., caffeine)MonitorLowTheoreticalInduction alters metabolism.
Timing
- With meals: Reduces GI upset; enhances absorption.
- Divided BID: Steady levels; e.g., 200 mg AM/PM.
References
Research
No published studies for Indole-3-Carbinol / DIM yet
New studies appear here once they’ve been reviewed. Browse all studies.
Dose: as studied, not a recommendation
Ranges seen in adjunct / practice use: 200–400 mg (po) I3C: 200–400 mg/day; DIM: 100–300 mg/day divided. Trials: 400 mg/day I3C for estrogen modulation. Preclinical HED from rat (50–200 mg/kg) ~8–32 mg/kg (~560–2240 mg for 70 kg); human uses lower for safety., From cruciferous extracts or pure. Divided BID with meals. Monitor hormones/LFTs. Not Rx; DIM more stable than I3C in acid..
Trials studying Indole-3-Carbinol / DIM
No actively-recruiting trials matched right now. Recruiting is not the same as proven. Search ClinicalTrials.gov →