Indole-3-Carbinol

Last Editorial Review: 6/11/2021
Other Name(s):

3-Hydroxymethyl Indole, 3 Hydroxymethyl Indole, I3C, Indole 3 Carbinol, 3-(hydroxymethyl), 3-(hydroxyméthyl), 3 (hydroxymethyl) Indole, 3-Indolylcarbinol, 3 Indolylcarbinol, 3-Indolylmethanol, 3 Indolylmethanol, Indol-3-Carbinol, Indole, Indole 3 Carbinol, Indole-3-methanol, Indole-3-méthanol.

Overview

Indole-3-carbinol is a substance found in vegetables such as broccoli, Brussels sprouts, cabbage, collards, cauliflower, kale, mustard greens, turnips, and rutabagas. It can also be produced in the laboratory.

Indole-3-carbinol is used for prevention of breast cancer, colon cancer, and other types of cancer. The National Institutes of Health (NIH) has reviewed indole-3-carbinol as a possible cancer preventive agent and is now sponsoring clinical research for breast cancer prevention.

Indole-3-carbinol is also used for fibromyalgia, tumors inside the voice box (laryngeal papillomatosis) caused by a virus, tumors inside the respiratory tract (respiratory papillomatosis) caused by a virus, abnormal cell growth in the cervix (cervical dysplasia), and systemic lupus erythematosus (SLE). Some people use indole-3-carbinol to balance hormone levels, “detoxify” the intestines and liver, and to support the immune system.

How does it work?

Researchers are interested in indole-3-carbinol for cancer prevention, particularly breast, cervical and endometrial, and colorectal cancer. Their reason is that diets with higher amounts of fruit and vegetable consumption are associated with a decreased risk of developing cancer. Researchers suspect indole-3-carbinol is one of several vegetable components that might protect against cancer.

SLIDESHOW

Vitamin D Deficiency: How Much Vitamin D Is Enough? See Slideshow

Uses & Effectiveness

Possibly Effective for...

Insufficient Evidence to Rate Effectiveness for...

  • Respiratory papillomatosis. There is some evidence that long-term use of indole-3-carbinol might reduce tumor (papilloma) growth in patients with recurrent respiratory papillomatosis.
  • Laryngeal papillomatosis.
  • Prevention of breast cancer.
  • Colon cancer.
  • Fibromyalgia.
  • Systemic lupus erythematosus (SLE).
  • Hormone imbalances.
  • Other conditions.
More evidence is needed to rate the effectiveness of indole-3-carbinol for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Side Effects

Indole-3-carbinol is likely safe for most people when used in amounts typically found in the diet. It seems to be safe for most people when used in medicinal amounts under proper medical supervision. It can cause side effects such as skin rashes and small increases in liver enzymes.

In very high doses, indole-3-carbinol can cause balance problems, tremor, and nausea.

QUESTION

Next to red peppers, you can get the most vitamin C from ________________. See Answer

Special Precautions & Warnings

Pregnancy and breast-feeding: If you are pregnant or breast-feeding, stick with indole-3-carbinol in amounts typically found in the diet. Not enough is known about the safety of using indole-3-carbinol in larger medicinal amounts.

Interactions


Medications changed by the liver (Cytochrome P450 1A2 (CYP1A2) substrates)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Some medications are changed and broken down by the liver. Indole-3-carbinol might increase how quickly the liver breaks down some medications. Taking indole-3-carbinol along with some medications that are changed by the liver can decrease the effectiveness of some medications. Before taking indole-3-carbinol, talk to your healthcare provider if you take any medications that are changed by the liver.

Some of these medications that are changed by the liver include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, zileuton (Zyflo), zolmitriptan (Zomig), and others.

Dosing

The following doses have been studied in scientific research:

BY MOUTH:

  • For treating abnormal cells on the surface of the cervix (cervical dysplasia): 200-400 mg per day has been used. However, 200 mg seems to be as effective as the higher dose.

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References

Anon. Broccoli compound inhibits HSV. AIDS Patient Care STDS 2003;17:609. View abstract.

Bailey GS, Dashwood RH, Fong AT, et al. Modulation of mycotoxin and nitrosamine carcinogenesis by indole-3-carbinol: quantitative analysis of inhibition versus promotion. IARC Sci Publ 1991;105:275-80. View abstract.

Balk JL. Indole-3-carbinol for cancer prevention. Altern Med Alert 2000; 3:105-7.

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. View abstract.

Bradlow HL, Michnovicz J, Telang NT, Osborne MP. Effects of dietary indole-3-carbinol on estradiol metabolism and spontaneous mammary tumors in mice. Carcinogenesis 1991;12:1571-4. View abstract.

Bradlow HL, Sepkovic DW, Telang NT, Osborne MP. Multifunctional aspects of the action of indole-3-carbinol as an antitumor agent. Ann N Y Acad Sci 1999;889:204-13. View abstract.

Dashwood RH. Indole-3-carbinol: anticarcinogen or tumor promoter in brassica vegetables? Chem Biol Interact 1998;110:1-5. View abstract.

Exon JH, South EH. Dietary indole-3-carbinol alters immune functions in rats. J Toxicol Environ Health A 2000;59:271-9. View abstract.

Grubbs CJ, Steele VE, Casebolt T, et al. Chemoprevention of chemically-induced mammary carcinogenesis by indole-3-carbinol. Anticancer Res 1995;15:709-16. View abstract.

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 cytochrome P450 in female F344 rats. Food Chem Toxicol 2000;38:15-23. View abstract.

Jin L, Qi M, Chen DZ, et al. Indole-3-carbinol prevents cervical cancer in human papilloma virus type 16 (HPV16) transgenic mice. Cancer Res 1999;59:3991-7. View abstract.

Kim DJ, Han BS, Ahn B, et al. Enhancement by indole-3-carbinol of liver and thyroid gland neoplastic development in a rat medium-term multiorgan carcinogenesis model. Carcinogenesis 1997;18:377-81. View abstract.

Kojima T, Tanaka T, Mori H. Chemoprevention of spontaneous endometrial cancer in female Donryu rats by dietary indole-3-carbinol. Cancer Res 1994;54:1446-9. View abstract.

Michnovicz JJ, Bradlow HL. Induction of estradiol metabolism by dietary indole-3-carbinol in humans. J Natl Cancer Inst 1990;82:947-9. View abstract.

Michnovicz JJ. Increased estrogen 2-hydroxylation in obese women using oral indole-3-carbinol. Int J Obes Relat Metab Disord 1998;22:227-9. View abstract.

Natl Inst Health, Natl Inst Environmental Health Sci. Indole-3-carbinol. Available at: http://ntp-server.niehs.nih.gov.

Pence BC, Buddingh F, Yang SP. Multiple dietary factors in the enhancement of dimethylhydrazine carcinogenesis: main effect of indole-3-carbinol. J Natl Cancer Inst 1986;77:269-76. View abstract.

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. View abstract.

Srivastava B, Shukla Y. Antitumour promoting activity of indole-3-carbinol in mouse skin carcinogenesis. Cancer Lett 1998;134:91-5. View abstract.

Telang NT, Katdare M, Bradlow HL, et al. Inhibition of proliferation and modulation of estradiol metabolism: novel mechanisms for breast cancer prevention by the phytochemical indole-3-carbinol. Proc Soc Exp Biol Med 1997;216:246-52. View abstract.

Wong GY, Bradlow L, Sepkovic D, et al. Dose-ranging study of indole-3-carbinol for breast cancer prevention. J Cell Biochem Suppl 1997;28-29:111-6. View abstract.

Yuan F, Chen DZ, Liu K, et al. Anti-estrogenic activities of indole-3-carbinol in cervical cells: implication for prevention of cervical cancer. Anticancer Res 1999;19:1673-80. View abstract.