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Dietary supplement

Indole-3-Carbinol 400 mg Ingredients & Drug Interactions

by Pure Encapsulations

Indole-3-Carbinol 400 mg label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Indole-3-Carbinol 400 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Indole-3-Carbinol 400 mg is a dietary supplement by Pure Encapsulations with 1 active ingredient. Its ingredients are commonly taken for estrogen and hormone balance support, breast and cervical health, prostate health.Based on those ingredients, 294 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Indole-3-Carbinol. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Indole-3-Carbinol 400 mg by Pure Encapsulations

Ask about any prescription or over-the-counter medication and we check it for interactions with Indole-3-Carbinol 400 mg by Pure Encapsulations — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Indole-3-Carbinol 400 mg by Pure Encapsulations

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: indole-3-carbinol at 400 mg per capsule. Indole-3-carbinol is a compound naturally found in cruciferous vegetables like broccoli and cabbage.

The capsule also contains inactive ingredients—cellulose, water, and hypoallergenic plant fiber—which are fillers and binders used to form and stabilize the capsule.

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

This is a single-ingredient Indole-3-carbinol product and its label doesn't state a use — see Indole-3-carbinol's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence for indole-3-carbinol is not established in the data we hold. The product is sometimes promoted for breast cancer, colorectal cancer, cervical dysplasia, liver disease, and fibromyalgia, but reliable evidence to support these uses is insufficient.

If you're considering this supplement for a specific health concern, talk with your pharmacist or doctor about what the current science actually shows.

The evidence, ingredient by ingredient Indole-3-carbinol

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Indole-3-carbinol is generally well tolerated when taken by mouth at supplement doses, though it's studied less thoroughly than food amounts. The most common side effects are diarrhea, nausea, rash, dizziness, tremor, and unsteadiness—especially at higher doses.

One case reported that an adult taking 400 mg twice daily developed imbalance and tremor after 10 days; the symptoms resolved when the dose was cut in half. Because of possible hormone effects and limited safety data, this supplement should be avoided during pregnancy.

Safety data is also insufficient during breastfeeding, so the evidence advises against use while nursing. If you're pregnant, planning to become pregnant, or breastfeeding, talk with your pharmacist or doctor before starting.

Side effects, ingredient by ingredient Indole-3-carbinol

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Indole-3-carbinol.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 294 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking Indole-3-Carbinol, double-check your medications with the tool on this page if you take blood thinners or antiplatelet drugs (like warfarin, aspirin, or clopidogrel)—this is a Moderate severity concern. Also check if you use estrogen therapy, including birth control or hormone replacement.

Several other medications that depend on liver enzyme CYP1A2 may be affected as well.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This is a single-ingredient supplement—indole-3-carbinol from broccoli-family vegetables. It interacts with blood thinners, estrogen therapy, and certain liver-metabolized drugs, so it's not a casual add-on if you're on prescription medications.

If you take a blood thinner, hormone replacement, or birth control, check with your pharmacist first.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jun 22, 2023.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Indole-3-Carbinol 400 mg, straight from the product label.

Brand Pure Encapsulations
Barcode (UPC) 766298005270
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Jun 22, 2023
DSLD ID 295517
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Indole-3-Carbinol 400 mg by Pure Encapsulations, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
120
UPC/BARCODE
766298005270
IngredientAmount% DV
Indole-3-Carbinol400 mg--

Other ingredients: Cellulose, Water, hypoallergenic Plant Fiber

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Storage

Keep refrigerated

Suggested/Recommended/Usage/Directions

Recommendations: As a dietary supplement, take 1 capsule, 1-2 times daily, with meals.

Precautions

Warning: Not to be taken by pregnant or lactating women. If you have any health condition or are taking any medication, consult your health professional before use.

Keep out of the reach of children.

Use only if safety seal is intact.

General Statements

Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity. Scan to learn about our hypoallergenic supplements

Seals/Symbols

GFCO.org (Gluten-Free Certification Organization)

Formulation

Certified Gluten-Free by the Gluten-Free Certification Organization, www.gluten.org

Supports cellular health

Gluten-free, Non-GMO & hypoallergenic

Gluten-free, Non-GMO & hypoallergenic

FDA Statement of Identity

Dietary Supplement

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Indole-3-Carbinol 400 mg by Pure Encapsulations label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Indole-3-Carbinol 400 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Indole-3-Carbinol 400 mg by Pure Encapsulations

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container120 Amounts shown are per serving.

Indole-3-Carbinol

Interacts with
294 drugs
400 mg per serving

Indole-3-carbinol (I3C) is a compound formed when you eat cruciferous vegetables like broccoli and cabbage, and it is sold as a supplement mainly for...

Indole-3-Carbinol monograph & interactions

Other (inactive) ingredients: Cellulose, Water, Hypoallergenic Plant Fiber. These complete the product’s ingredient list but are not active constituents.

Interaction report

Indole-3-Carbinol 400 mg by Pure Encapsulations Drug Interactions

Want to check YOUR meds against Indole-3-Carbinol 400 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
294Drugs
294 Moderate

Ingredients driving the most interactions

Indole-3-Carbinol 294

Individual Drug Interactions

The ingredients in Indole-3-Carbinol 400 mg interact with 294 drugs. Click any drug to see the details.

1 of the 1 ingredient in Indole-3-Carbinol 400 mg interact with drugs. Each result below shows which ingredient is responsible. Indole-3-Carbinol

Each ingredient & the kinds of drugs it affects

For each ingredient in Indole-3-Carbinol 400 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Indole-3-Carbinol3 drug types · 294 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, indole-3-carbinol might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.
In vitro research shows that indole-3-carbinol inhibits platelet aggregation.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, indole-3-carbinol might increase the metabolism of CYP1A2 substrates and lower serum concentrations.
Animal research shows that indole-3-carbinol induces CYP1A2 enzymes.

Likelihood Possible Evidence D
Estrogens

Indole-3-carbinol might interfere with the effects of estrogen therapy.
Preliminary clinical and in vitro evidence shows that indole-3-carbinol has antiestrogenic activity.

Likelihood Possible Evidence D
Indole-3-Carbinol full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Indole-3-Carbinol 400 mg, from the product label.

Pure Encapsulations

See all Pure Encapsulations products
Name
Pure Encapsulations
Street Address
490 Boston Post Road
City
Sudbury
State
MA
Phone Number
1-800-753-2277
Web Address
www.PureEncapsulations.com
Pharmacist Counseling Corner

Indole-3-Carbinol 400 mg by Pure Encapsulations: Common Questions

Does Indole-3-Carbinol 400 mg by Pure Encapsulations interact with any medications?
Yes. Based on its ingredients, Indole-3-Carbinol 400 mg has a known interaction with 294 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Indole-3-Carbinol 400 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
What is indole-3-carbinol and where does it come from?
Indole-3-carbinol is a compound naturally found in cruciferous vegetables—broccoli, cabbage, and similar greens. This supplement gives you a concentrated 400 mg dose of that compound in capsule form.
Will it really work for breast cancer, cancer prevention, or hormone balance?
The evidence isn't established well enough to say. The product is marketed for breast cancer, cervical dysplasia, liver disease, and other conditions, but reliable evidence supporting those uses is insufficient right now. Talk with your doctor if you're considering it for a specific health goal.
What are the most common side effects?
Diarrhea and nausea are the most frequently reported. Some people also experience dizziness, tremor, unsteadiness, or rash. Higher doses are more likely to cause dizziness and balance problems—one adult taking 400 mg twice daily developed these symptoms after 10 days, but they went away when the dose was reduced.
Can I take this while pregnant or breastfeeding?
No—safety data advises against use in both pregnancy and breastfeeding due to possible hormone effects and limited safety information. If you're pregnant, planning pregnancy, or nursing, talk with your pharmacist or doctor before starting.
Does it have a lot of fillers or other junk in it?
The capsule contains cellulose, water, and hypoallergenic plant fiber as inactive ingredients—these are standard binders and fillers that hold the supplement together. There's no other active ingredient; the product is just the 400 mg of indole-3-carbinol.
Is it safe to take with my other medications?
That depends on what you take. This supplement interacts with blood thinners, estrogen therapy, and some other medications metabolized by your liver. Use the medication checker on this page with your exact drugs, or ask your pharmacist before you start.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Indole-3-Carbinol 400 mg label
Go deeper

The Full Monographs Behind Indole-3-Carbinol 400 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Indole-3-carbinol

Interacts with 294 drugs

Indole-3-carbinol (I3C) is a compound formed when you eat cruciferous vegetables like broccoli and cabbage, and it is sold as a supplement mainly for hormone-related and cell-protective effe...

Read the full Indole-3-carbinol monograph →
Sources

Sources & How We Checked

Indole-3-Carbinol 400 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 9 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Indole-3-carbinol 9 references
  1. Rosen CA, Woodson GE, Thompson JW, et al. Preliminary results of the use of indole-3-carbinol for recurrent respiratory papillomatosis. Otolaryngol Head Neck Surg 1998;118:810-5. PubMed
  2. Bell MC, Crowley-Nowick P, Bradlow HL, et al. Placebo-controlled trial of indole-3-carbinol in the treatment of CIN. Gynecol Oncol 2000;78:123-9. PubMed
  3. He YH, Friesen MD, Ruch RJ, Schut HA. Indole-3-carbinol as a chemopreventive agent in 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) carcinogenesis: inhibition of PhIP-DNA adduct formation, acceleration of PhIP metabolism, and induction of cytoch
  4. Kim, Y. S. and Milner, J. A. Targets for indole-3-carbinol in cancer prevention. J.Nutr.Biochem. 2005;16(2):65-73. PubMed
  5. Anon. Indole-3-carbinol. Monograph. Alternative Medicine Review 2005;10(4):337-42.
  6. McAlindon TE, Gulin J, Chen T, et al. Indole-3-carbinol in women with SLE: effect on estrogen metabolism and disease activity. Lupus 2001;10:779-83. PubMed
  7. Reed GA, Peterson KS, Smith HJ, et al. A phase I study of indole-3-carbinol in women: tolerability and effects. Cancer Epidemiol Biomarkers Prev 2005;14:1953-60. PubMed
  8. Bradlow HL, Michnovicz JJ, Halper M, et al. Long-term responses of women to indole-3-carbinol or a high fiber diet. Cancer Epidemiol Biomarkers Prev 1994;3:591-5.
  9. Paliwal P, Chauhan G, Gautam D, Dash D, Patne SCU, Krishnamurthy S. Indole-3-carbinol improves neurobehavioral symptoms in a cerebral ischemic stroke model. Naunyn Schmiedebergs Arch Pharmacol. 2018;391(6):613-625. PubMed

See these in context on the Indole-3-carbinol monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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