We’re busy updating our review of diindolylmethane and will provide a rating when that’s complete. While we’re working, we share a summary from our predecessor website, Beyond Conventional Cancer Therapies. The information we share here was last updated in November 2020.

Please consider supporting our update and revision to this information.

What is DIM?

DIM, a glucosinolate, is produced in the stomach when digesting cruciferous vegetables that contain indole-3-carbinol (I3C):

  • Broccoli
  • Cauliflower
  • Brussels sprouts
  • Cabbage
  • Kale

DIM is also available as a nutritional supplement. Raymond Chang, MD, FACP, advises taking a supplement with a light meal to enhance absorption.1

Treating the Cancer

Working against cancer growth or spread, improving survival, or working with other treatments or therapies to improve their anticancer action

Clinical Evidence

In patients taking tamoxifen for breast cancer, daily DIM promoted favorable changes in estrogen metabolism and circulating levels of sex hormone-binding globulin. However, use was associated with decreases in tamoxifen metabolites, including endoxifen. DIM’s impact on the clinical benefit of tamoxifen is unknown.2

Lab and Animal Evidence

  • DIM showed anti-inflammatory3 and antiproliferative4 effects in lab and animal studies.
  • It prevented metastatic behaviors of breast cancer cells induced by endocrine-disrupting chemicals5
  • DIM induced cell death (apoptosis) in ovarian cancer cells and suppressed the activation of factors related to ovarian cancer growth in preclinical studies.6
  • Lab studies suggest DIM might enhance the effect of some chemotherapy drugs, such as paclitaxel.7

Reducing Risk

Reducing the risk of developing cancer or the risk of recurrence

Lab and Animal Evidence

Lab and animal studies suggest that DIM might help reduce the risk of various types of cancer, especially breast,,8 cervical, prostate and uterine. DIM has complex interactions with estrogen, which may explain some of its benefit in cancer. It also inhibits testosterone and androgen-receptor activity.


Although DIM is considered relatively nontoxic, comprehensive safety studies have not been completed. DIM can cause side effects and drug interactions. Consult with your pharmacist for interactions, and discuss using DIM with your doctor.

Preliminary evidence indicates that DIM may attenuate the clinical benefit of tamoxifen; precaution guides that it should not be used during tamoxifen treatment.9


DIM is widely available in food sources and in supplements.


BCCT does not recommend therapies or doses, but only provides information for patients and providers to consider as part of a complete treatment plan. Patients should discuss therapies with their physicians, as contraindications, interactions and side effects must be evaluated. Levels of active ingredients of natural products can vary widely between and even within products. See Quality and Sources of Herbs, Supplements and Other Natural Products.

No optimal DIM dose in cancer prevention or treatment has been established. Dosage recommendations are available from these sources:

Integrative Programs, Protocols and Medical Systems

Alschuler & Gazella complementary approaches10

  • Breast cancer
  • Colon cancer
  • Endometrial cancer
  • Lung cancer
  • Prostate cancer

Block program11

Lemole, Mehta & McKee protocols12

  • Bladder cancer
  • Breast cancer
  • Colon cancer
  • Leukemia
  • Lymphoma
  • Prostate cancer
  • Thyroid cancer

McKinney protocols13

  • General cancer
  • Breast cancer
  • Cervical cancer
  • Colorectal cancer
  • Head and neck cancer
  • Kidney cancer
  • Leukemia
  • Lymphoma
  • Multiple myeloma
  • Ovarian cancer
  • Pancreatic cancer
  • Prostate cancer
  • Uterine cancer

Note: BCCT has not conducted an independent review of research of DIM. This summary draws primarily from the Memorial Sloan Kettering Cancer Center’s About Herbs and The Lonestar Medical Group Health Library websites.



Laura Pole, RN, MSN, OCNS, BCCT Senior Researcher Nancy Hepp, MS, BCCT Project Manager
Last updated November 18, 2020.


  1. Chang, R. Beyond the Magic Bullet: The Anti-Cancer Cocktail. New York: Square One Publishers. 2012.
  2. Thomson CA, Chow HHS et al. A randomized, placebo-controlled trial of diindolylmethane for breast cancer biomarker modulation in patients taking tamoxifen. Breast Cancer Research and Treatment. 2017 Aug;165(1):97-107.
  3. Ampofo E, Schmitt BM, Menger MD, Laschke MW. Targeting the microcirculation by indole-3-carbinol and its main derivate 3,3,’-diindolylmethane: effects on angiogenesis, thrombosis and inflammation. Mini Reviews in Medicinal Chemistry. 2018;18(11):962-968.
  4. Firestone GL, Bjeldanes LF. Indole-3-carbinol and 3-3′-diindolylmethane antiproliferative signaling pathways control cell-cycle gene transcription in human breast cancer cells by regulating promoter-Sp1 transcription factor interactions. Journal of Nutrition. 2003 Jul;133(7 Suppl):2448S-2455S.
  5. Lee GA, Hwang KA, Choi KC. Inhibitory effects of 3,3′-diindolylmethane on epithelial-mesenchymal transition induced by endocrine disrupting chemicals in cellular and xenograft mouse models of breast cancer. Food and Chemical Toxicology. 2017 Nov;109(Pt 1):284-295.
  6. Kandala PK, Srivastava SK. Regulation of Janus-activated kinase-2 (JAK2) by diindolylmethane in ovarian cancer in vitro and in vivo. Drug Discoveries & Therapeutics. 2012 Apr;6(2):94-101; Kandala PK, Srivastava SK. DIMming ovarian cancer growth. Current Drug Targets. 2012 Dec;13(14):1869-75.
  7. Jin H, Park MH, Kim SM. 3,3′-Diindolylmethane potentiates paclitaxel-induced antitumor effects on gastric cancer cells through the Akt/FOXM1 signaling cascade. Oncology Reports. 2015 Apr;33(4):2031-6
  8. Thomson CA, Ho E, Strom MB. Chemopreventive properties of 3,3′-diindolylmethane in breast cancer: evidence from experimental and human studies. Nutrition Reviews. 2016 Jul;74(7):432-43.
  9. Thomson CA, Chow HHS et al. A randomized, placebo-controlled trial of diindolylmethane for breast cancer biomarker modulation in patients taking tamoxifen. Breast Cancer Research and Treatment. 2017 Aug;165(1):97-107.
  10. Alschuler & Gazella complementary approachesAlschuler LN, Gazella KA. The Definitive Guide to Cancer, 3rd Edition: An Integrative Approach to Prevention, Treatment, and Healing. Berkeley, California: Celestial Arts. 2010.
  11. Block KI. Life over Cancer: The Block Center Program for Integrative Cancer Treatment. New York: Bantam Dell. 2009.
  12. Lemole G, Mehta P, McKee D. After Cancer Care: The Definitive Self-Care Guide to Getting and Staying Well for Patients with Cancer. New York, New York: Rodale, Inc. 2015.
  13. McKinney N. Naturopathic Oncology, 3rd Edition. Victoria, BC, Canada: Liaison Press. 2016.