Diindolylmethane for Cancer

Diindolylmethane (DIM) for Cancer: Safety & Side Effects

This page covers safety information for Diindolylmethane (DIM). See our complete Diindolylmethane (DIM) therapy guide →

Author

Nancy Hepp, MS

past Lead Researcher

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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher and writer for CancerChoices and also served as the first program manager. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS past Lead Researcher

Clinical reviewer

Laura Pole, MSN, RN, OCNS

Senior Clinical Consultant

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Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.

For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.

Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.

Laura Pole, MSN, RN, OCNS Senior Clinical Consultant

Last update: July 9, 2026

Side effects and adverse reactions

• Discolored urine¹Thomson 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; Castañon A, Tristram A et al. Effect of diindolylmethane supplementation on low-grade cervical cytological abnormalities: double-blind, randomised, controlled trial. British Journal of Cancer. 2012 Jan 3;106(1):45-52.
• Vomiting²Reed GA, Sunega JM, et al. Single-dose pharmacokinetics and tolerability of absorption-enhanced 3,3′-diindolylmethane in healthy subjects. Cancer Epidemiology, Biomarkers, and Prevention. 2008;17(10):2619-2624.
• Nausea and diarrhea³Paltsev M, Kiselev V et al. Safety and tolerability of DIM-based therapy designed as personalized approach to reverse prostatic intraepithelial neoplasia (PIN). EPMA J. 2014;5(1):18; Heath EI, Heilbrun LK et al. A phase I dose-escalation study of oral BR-DIM (BioResponse 3,3′- Diindolylmethane) in castrate-resistant, non-metastatic prostate cancer. American Journal of Translational Research. 2010 Jul 23;2(4):402-11; Del Priore G, Gudipudi DK et al. Oral diindolylmethane (DIM): pilot evaluation of a nonsurgical treatment for cervical dysplasia. Gynecological Oncology. 2010 Mar;116(3):464-7.
• Hives (urticaria), burning, and vaginal itching⁴Ashrafian L, Sukhikh G et al. Double-blind randomized placebo-controlled multicenter clinical trial (phase IIa) on diindolylmethane’s efficacy and safety in the treatment of CIN: implications for cervical cancer prevention. EPMA Journal. 2015 Dec 21;6:25.
• Headache⁵Hwang C, Sethi S et al. Anti-androgenic activity of absorption-enhanced 3, 3′-diindolylmethane in prostatectomy patients. American Journal of Translational Research. 2016 Jan 15;8(1):166-76.
• High blood sugar (hyperglycemia)⁶Heath EI, Heilbrun LK et al. A phase I dose-escalation study of oral BR-DIM (BioResponse 3,3′- Diindolylmethane) in castrate-resistant, non-metastatic prostate cancer. American Journal of Translational Research. 2010 Jul 23;2(4):402-11.
• Rash, joint pain (arthralgias), hot flashes, and nausea⁷Dalessandri KM, Firestone GL, Fitch MD, Bradlow HL, Bjeldanes LF. Pilot study: effect of 3,3′-diindolylmethane supplements on urinary hormone metabolites in postmenopausal women with a history of early-stage breast cancer. Nutrition and Cancer. 2004;50(2):161-7.
• Change in bowel movements, headache, nauseas, and atopic dermatitis⁸Yerushalmi R, Bargil S et al. 3,3-Diindolylmethane (DIM): a nutritional intervention and its impact on breast density in healthy BRCA carriers. A prospective clinical trial. 2020;41(10):1395-1401.
• Low sodium (hyponatremia)⁹Heath EI, Heilbrun LK et al. A phase I dose-escalation study of oral BR-DIM (BioResponse 3,3′- Diindolylmethane) in castrate-resistant, non-metastatic prostate cancer. American Journal of Translational Research. 2010 Jul 23;2(4):402-11. 

Fluid under the retina (central serous chorioretinopathy), headaches, and blurry vision were reported by one person taking high levels of DIM.¹⁰Bussel II, Lally DR, Waheed NK. Bilateral central serous chorioretinopathy associated with estrogen modulator diindolylmethane. Ophthalmic Surgery, Lasers and Imaging Retina. 2014;45(6):589-591.

Contraindications

Pregnant and breastfeeding women, and women planning to get pregnant, should avoid DIM due to its potential effects on hormones. Women using birth control pills should consult with a physician before taking DIM.

Drug interactions 

DIM has the potential to interact with tamoxifen, commonly prescribed to prevent or treat breast cancer.¹¹Thomson 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. 

DIM may potentially interact with estrogens, diuretics, or medications changed by the liver, such as clozapine, cyclobenzaprine, and propranolol.¹²Diindolylmethane. Rx List. June 11, 2021. Viewed January 13, 2023. 

Interactions with medications and other interventions are complex. Always consult with a healthcare professional before adding any new therapy to your regimen. To learn more about interactions visit one of the trusted resources below: 

• About Herbs ›
• EfficaSafe ›

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