Hormonal/Women

Indole-3-carbinol

Cruciferous vegetable compound that may shift estrogen metabolism and support cervical health in women.

Indole-3-carbinol

Cruciferous vegetable compound that may shift estrogen metabolism and support cervical health in women.

score

evidence

Caution

risk

Proven Benefits

01Shifts estrogen metabolites

02May improve cervical dysplasia

03May reduce breast cell proliferatio

Chemical Forms

Recommended

Indole-3-carbinol (I3C)

Avoid

DIM (different compound; not interchangeable)
Unstandardized cruciferous extracts (variable I3C content)

Expert Note

I3C is the compound studied in most clinical trials, but it is unstable and forms DIM and other oligomers after ingestion. DIM is the main breakdown product, yet it is not dose-equivalent to I3C; standardized I3C capsules are the best match to the research.

Protocol

Amount

200-400 mg

Frequency

Once daily

When

With food to reduce stomach upset; any time of day is fine.

Safety & Limits

Upper Safe Limit

800 mg/day (highest short-term studied dose without major adverse effects; no official UL)

Cycling

8-12 weeks on, then reassess; avoid indefinite continuous use without clinician review.

Contraindications

Pregnancy or breastfeeding — insufficient safety data and hormonal activity may be unsafe

Hormone-sensitive cancers — use only with oncology guidance because estrogen metabolism is altered

Liver disease or hepatitis — rare hepatotoxicity reported; avoid unless cleared by a clinician

Medications metabolized by CYP1A2 — enzyme induction may alter drug concentrations

Avoid Combining With

✕CYP1A2 substrates like theophylline, clozapine, and caffeine (may lower drug levels)
✕Hormonal contraceptives or HRT (may alter hormone exposure; coordinate with prescriber)

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