Diindolylmethane

Diindolylmethane (DIM) is created naturally when you digest cruciferous vegetables, and it’s also a nutritional supplement with possible anticancer effects.

Safety and precautions

Side effects or adverse events

Adverse events and side effects reported in studies have typically been few and mild: 

• 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.

Interactions with other therapies

DIM use was linked to lower plasma tamoxifen metabolites among women prescribed tamoxifen, indicating potential interaction or interference with tamoxifen.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, propranolol, and others.¹²Diindolylmethane. Rx List. June 11, 2021. Viewed January 13, 2023. A possible caution with poly (adenosine diphosphate-ribose) polymerase inhibitor drugs (PARP inhibitors) is noted.¹³Parmar G, Kaczor T. Textbook of Naturopathic Oncology: A Desktop Guide of Integrative Cancer Care. 1st edition. Medicatrix Holdings Ltd. 2020.

Helpful link

Keep reading about diindolylmethane

Learn more