HomeBlogDIM Supplement Complete Guide — Oestrogen Metabolism for Men
WellnessChecked Editorial · July 2026

DIM Supplement Complete Guide — Oestrogen Metabolism for Men

DIM (Diindolylmethane) modulates oestrogen metabolism via liver CYP enzymes. Complete guide — mechanism, clinical dose (300-500mg), what to look for in a DIM supplement.

⚡ Quick AnswerLast Reviewed: July 2026

DIM (Diindolylmethane) is formed during digestion of cruciferous vegetables. At 300-500mg daily it modulates liver CYP enzyme activity to favour beneficial oestrogen metabolites and support a healthier testosterone-to-oestrogen ratio in men. Most supplements contain under-dosed 50-100mg.

What Is DIM?

DIM (Diindolylmethane) is a stable indole formed in the gut during digestion of indole-3-carbinol (I3C) — a compound found in cruciferous vegetables including broccoli, Brussels sprouts and cauliflower. At supplement doses, DIM modulates the liver CYP450 enzyme system involved in oestrogen metabolism.

The Oestrogen Metabolism Mechanism

The liver processes oestrogen via hydroxylation pathways. Two primary metabolites result: 2-hydroxyestrone (considered beneficial) and 16α-hydroxyestrone (considered less desirable). DIM modulates CYP1A1 and CYP1B1 enzymes to shift metabolism toward the 2-hydroxy pathway — resulting in a more favourable oestrogen metabolite ratio.

Why Men Need DIM

As men age, adipose (fat) tissue increases in aromatase enzyme activity — converting testosterone to oestrogen. This can produce an unfavourable testosterone-to-oestrogen ratio. DIM supports oestrogen clearance and favourable metabolism, helping to maintain hormonal balance.

📚 Clinical Reference: DIM oestrogen metabolism research. PubMed: 21067940

The Dose Problem

Most DIM supplements contain 50-100mg per serving. The clinical dose supported by published research is 300-500mg daily. DIM3X is the only supplement we have reviewed containing the full 500mg clinical dose.

Read Our DIM3X Review →
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Frequently Asked Questions

DIM is Diindolylmethane — formed from cruciferous vegetables. At 300-500mg it modulates liver oestrogen metabolism to support a healthier testosterone-to-oestrogen ratio in men.

300-500mg daily — the published research dose. Most commercial products contain only 50-100mg, which is unlikely to produce the same effects.

DIM shifts oestrogen metabolism toward beneficial 2-hydroxy metabolites, supports testosterone-to-oestrogen ratio balance and may help with body composition.

DIM is formed from I3C in broccoli. However, supplement doses of 300-500mg DIM would require consuming impractical amounts of broccoli.

Well tolerated at recommended doses. Some users notice altered urine odour — a sign of active oestrogen metabolism. Consult GP if taking prescription medication.

Disclaimer: For informational purposes only. Dietary supplements — not medicines. Not intended to diagnose, treat, cure or prevent any disease. FDA/MHRA not evaluated. Individual results vary. Consult healthcare professional. Affiliate commissions may be earned. Full disclaimer →