Skip to main content
Supplement ScienceSupplementScience

DIM (Diindolylmethane) Side Effects & Safety

Evidence:Moderate
·

This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Safety Profile

Overall safety rating: Generally Safe

Potential Side Effects

  • Darkened urine (harmless — DIM metabolites are colored)
  • Changes in menstrual cycle timing or flow
  • Mild headache during initial use
  • GI symptoms (gas, bloating) at higher doses
  • Rarely: skin breakouts during initial estrogen metabolism shift

Drug & Supplement Interactions

  • Induces CYP1A2 — may increase metabolism of caffeine, theophylline, and certain antidepressants
  • May reduce effectiveness of oral contraceptives by enhancing estrogen metabolism
  • Caution with tamoxifen and aromatase inhibitors — DIM affects estrogen metabolism and may interact
  • May interact with immunosuppressants metabolized by CYP1A2

Maximum Dose

Do not exceed: 300mg BioResponse DIM/day (higher doses used in clinical oncology trials)

Looking for a well-tested DIM (Diindolylmethane)?
All our top picks are third-party verified for purity
Full DIM (Diindolylmethane) Guide

References

  1. Dalessandri KM, Firestone GL, Fitch MD, Bradlow HL, Bjeldanes LF (2004). 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. DOI PubMed
  2. Bjeldanes LF, Kim JY, Grose KR, Bartholomew JC, Bradfield CA (1991). Aromatic hydrocarbon responsiveness-receptor agonists generated from indole-3-carbinol in vitro and in vivo: comparisons with 2,3,7,8-tetrachlorodibenzo-p-dioxin. Proceedings of the National Academy of Sciences. DOI PubMed
  3. Reed GA, Sunega JM, Sullivan DK, Gray JC, Mayo MS, Crowell JA, Hurwitz A (2005). Single-dose pharmacokinetics and tolerability of absorption-enhanced 3,3'-diindolylmethane in healthy subjects. Cancer Epidemiology, Biomarkers & Prevention. DOI PubMed
  4. Le HT, Schaldach CM, Bheldanes LF, Firestone GL (2003). Plant-derived 3,3'-Diindolylmethane is a strong androgen antagonist in human prostate cancer cells. Journal of Biological Chemistry. DOI PubMed