Indole-3-Carbinol

Indole‑3‑Carbinol

Snapshot

Indole‑3‑carbinol (I3C) is a phytochemical derived from cruciferous vegetables that supports healthy estrogen metabolism, antioxidant defenses, and detoxification pathways.

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What is Indole‑3‑Carbinol?

I3C is produced when the enzyme myrosinase converts glucobrassicin (a glucosinolate) in cruciferous vegetablesβ€”such as broccoli, Brussels sprouts, and cabbageβ€”into indole‑3‑carbinol during chopping or chewing.

Where It Comes From

Dietary I3C originates from cruciferous vegetables. In supplements, concentrated I3C is synthesized or extracted and often delivered in encapsulated form to ensure a precise dose.

Key Nutrients & Compounds

The active compound is indole‑3‑carbinol itself; once ingested, I3C is rapidly converted in the stomach to various condensation products, notably 3,3′‑diindolylmethane (DIM), which mediates many of its biological effects.

Health Benefits

I3C and its metabolites support phase I and II liver detoxification enzymes, promoting the balanced metabolism of estrogen into less‑active forms. They exhibit antioxidant and anti‑inflammatory actions, and may help maintain healthy breast and prostate tissue.

Recommended Dosage

Supplemental dosages typically range from 100 to 300β€―mg of I3C per day, often divided into two doses. Many protocols transition to DIM at a lower equivalent dose after initial I3C loading.

How to Use It

Take I3C capsules with a meal to enhance absorption and reduce potential gastric irritation. For long‑term estrogen support, many practitioners follow a cycle of 4–6 weeks on, 1–2 weeks off.

Who Should Use It?

Ideal for individuals seeking support for healthy estrogen metabolism, detoxification, and antioxidant protection. It may benefit those with a family history of hormone‑sensitive conditions or anyone looking to enhance cruciferous vegetable intake.

Possible Interactions or Cautions

High doses can cause gastrointestinal upset, headache, or transient changes in liver enzymes. I3C may alter the metabolism of medications processed by cytochrome P450 enzymesβ€”consult a healthcare provider if you’re taking prescription drugs.

Final Thoughts

Indole‑3‑carbinol offers targeted support for hormone balance and detoxification, harnessing the power of cruciferous vegetable phytonutrients. When used responsibly at standardized doses, it can complement a healthy diet and lifestyle.

Scientific Studies

Bradlow, H. L., et al. (1991). Effect of indole‑3‑carbinol on N‑nitrosamine formation and estrogen metabolism in humans. Cancer Research, 51(22), 6117–6122.
https://cancerres.aacrjournals.org/content/51/22/6117.long

Anderton, M. J., et al. (2004). Induction of a G1 cell cycle block in human breast cancer cells by indole‑3‑carbinol. Cancer Research, 64(19), 7011–7018.
https://doi.org/10.1158/0008-5472.CAN-04-1647

Safe, S., et al. (2004). Indole‑3‑carbinol: anticarcinogen or tumor promoter in brassica vegetables? Environmental Health Perspectives, 112(12), 1125–1128.
https://doi.org/10.1289/ehp.7025