library.onepin.app/dim-diindolylmethane Peptide Education Library
Education only, not medical advice 21+ Every dose is an example to finalize with a licensed provider

OnePin Peptide Library · Metabolic

Metabolic Peptide Prescription drug

DIM (Diindolylmethane)

Diindolylmethane

Diindolylmethane (DIM) is a phytochemical formed from indole-3-carbinol (I3C) when cruciferous vegetables (broccoli, kale, cabbage, Brussels sprouts) are chewed and digested. I3C dimerizes in the acidic stomach environment to form DIM, which is the more bioavailable and stable active metabolite. While DIM occurs naturally in cruciferous vegetables, achieving therapeutic doses through diet alone requires impractical quantities (~2lb of broccoli daily for 100mg DIM).,DIM modulates estrogen metabolism by shifting the balance from less-favorable estrogen metabolites (16-alpha-hydroxyestrone, 4-hydroxyestrogens) toward more-favorable 2-hydroxyestrogens. The 2:16 hydroxyestrogen ratio is a marker of estrogen metabolism quality - higher ratios are associated with reduced breast and uterine cancer risk. DIM is one of the most clinically validated approaches to favorably shift this ratio.,DIM is widely used by men for estrogen management (especially when on testosterone replacement therapy or when aromatization is elevated) and by women for hormonal symptoms (estrogen dominance, fibroids, fibrocystic breasts, PCOS). It is NOT an aromatase inhibitor (does not reduce estrogen production) but rather modulates how estrogen is metabolized and cleared. This makes DIM a 'preserve cardioprotective estrogen, redirect harmful metabolites' tool rather than an estrogen-blocker.

Quick Start
Route
Oral
Start low
100-200mg microencapsulated DIM
Frequency
1-2x daily with meals
Timing
Anytime

Take with a meal containing fat for best absorption (DIM is fat-soluble). Start with 100mg/day to assess tolerance, titrate up to 200-300mg over 1-2 weeks. Monitor estradiol levels every 6-8 weeks if on TRT to avoid over-suppression.

Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.

Tiered Protocols · lowest first
Quick Start
Conservative start
100-200mg microencapsulated DIM · Oral · 1-2x daily with meals
Lowest starting point. Hold about a week to assess tolerance before stepping up.
100-200mg microencapsulated DIM
1-2x daily with meals
Standard
Estrogen Balance
100-200 mg · Oral · Daily
human clinical trial · Rajoria et al. 2011 (Thyroid)
100-200 mg
Daily
01

How it works

DIM induces cytochrome P450 1A1 (CYP1A1), the enzyme that hydroxylates estrogens at the 2-position to form 2-hydroxyestrone (2-OHE1) and 2-hydroxyestradiol. This shifts metabolism away from the 16-alpha-hydroxylation pathway (forms 16-alpha-hydroxyestrone, a more proliferative metabolite associated with cancer risk).,The 2-hydroxyestrogens are weaker estrogen receptor agonists, more easily methylated and excreted, and may have anti-proliferative effects. Increased 2:16 ratio is associated with reduced breast cancer risk in observational studies.,DIM modulates androgen receptor activity - has weak antagonist activity at androgen receptors in some tissues (relevant for prostate). It does NOT block testosterone systemically but may modify androgen signaling locally.,DIM activates the aryl hydrocarbon receptor (AhR), which has multiple downstream effects including induction of phase I and phase II detoxification enzymes (UGTs, GSTs, sulfotransferases). This supports general xenobiotic and estrogen clearance.,Anti-proliferative effects: DIM has been shown to induce apoptosis in cancer cell lines (breast, prostate, cervical) via cell cycle arrest, NF-kB inhibition, and modulation of survival signaling. Clinical relevance for cancer prevention/treatment is still being studied.,Aromatase: DIM is NOT a strong aromatase inhibitor at typical supplement doses. Its estrogen-management effects are post-aromatization (metabolite shifting) rather than blocking estrogen production.

DIM induces cytochrome P450 1A1 (CYP1A1), the enzyme that hydroxylates estrogens at the 2-position to form 2-hydroxyestrone (2-OHE1) and 2-hydroxyestradiol. This shifts metabolism away from the 16-alpha-hydroxylation pathway (forms 16-alpha-hydroxyestrone, a more proliferative metabolite associated with cancer risk).,The 2-hydroxyestrogens are weaker estrogen receptor agonists, more easily methylated and excreted, and may have anti-proliferative effects. Increased 2:16 ratio is associated with reduced breast cancer risk in observational studies.,DIM modulates androgen receptor activity - has weak antagonist activity at androgen receptors in some tissues (relevant for prostate). It does NOT block testosterone systemically but may modify androgen signaling locally.,DIM activates the aryl hydrocarbon receptor (AhR), which has multiple downstream effects including induction of phase I and phase II detoxification enzymes (UGTs, GSTs, sulfotransferases). This supports general xenobiotic and estrogen clearance.,Anti-proliferative effects: DIM has been shown to induce apoptosis in cancer cell lines (breast, prostate, cervical) via cell cycle arrest, NF-kB inhibition, and modulation of survival signaling. Clinical relevance for cancer prevention/treatment is still being studied.,Aromatase: DIM is NOT a strong aromatase inhibitor at typical supplement doses. Its estrogen-management effects are post-aromatization (metabolite shifting) rather than blocking estrogen production.

02

What to expect

Early
Days 1–7

Week 1-2: Initial metabolite shift, possible mild side effects (headache, urine color).

03

Evidence

HumanModerate
AnimalPresent
In-vitroPresent
20113,3'-diindolylmethane modulates estrogen metabolism in patients with thyroid proliferative disease: a pilot study · Rajoria S, Suriano R, Parmar PS, et al, Thyroid ↗peer reviewed
2017Effect of Diindolylmethane on Estrogen-related Hormones, Metabolites and Tamoxifen Metabolism: Results of a Randomized, Placebo-controlled Trial · Thomson CA, Chow HHS, Wertheim BC, et al, Cancer Epidemiology, Biomarkers & Prevention ↗peer reviewed
20203,3-Diindolylmethane (DIM): a nutritional intervention and its impact on breast density in healthy BRCA carriers. A prospective clinical trial · Kotsopoulos J, Zhang S, Akbari M, et al, Carcinogenesis ↗peer reviewed
2025The impact of 3,3'-diindolylmethane on estradiol and estrogen metabolism in postmenopausal women using a transdermal estradiol patch · Sepkovic DW, Stein J, Carlisle AD, et al, Climacteric ↗peer reviewed
04

Interactions & stacking

What's safe to combine, and what belongs in a separate pin.

Safe & synergistic

TRT (Testosterone Replacement)DIM is widely used adjunct to TRT for estrogen management. Generally well-tolerated and synergistic.
Calcium D-GlucarateCDG inhibits beta-glucuronidase, preventing reabsorption of conjugated estrogens excreted via bile. Combined with DIM's 2-hydroxylation shift, comprehensive estrogen clearance support.
Sulforaphane (Broccoli Sprout Extract)Both from cruciferous vegetable family with overlapping detoxification support. Sulforaphane induces phase II enzymes complementing DIM's phase I induction.
MagnesiumMagnesium is required cofactor for COMT (methylates 2-hydroxyestrogens for excretion). Without adequate magnesium, increased 2-OH metabolites can accumulate as DNA-damaging quinones.

Keep separate

TamoxifenTheoretical interaction - DIM may modulate tamoxifen metabolism. Discuss with oncologist before combining.
Aromatase Inhibitors (anastrozole, exemestane)Combined estrogen reduction may be excessive. Use carefully and monitor estradiol if combining.
CYP1A2 Substrate MedicationsDIM induces CYP1A2 (caffeine, theophylline, clozapine, olanzapine, propranolol, others). Monitor effects of these medications.
Hormonal ContraceptivesDIM may modify estrogen levels in oral contraceptives. Theoretical reduction in efficacy - discuss with prescriber.
05

Pharmacokinetics

Illustrative plasma concentration · 24 h
Half-life
~12 hours plasma for DIM metabolites.
Peak · Tmax
~3-6 hours oral with food (BioResponse form).
Elimination
Plasma clearance 24-48 hours; tissue effects on estrogen metabolism build over weeks.
Activity
Acute CYP1A1 induction: 12-24 hours. Chronic estrogen metabolism shift: 4-12 weeks of consistent dosing.

Storage. Store at room temperature (20-25C) in a cool, dry place. Protect from light. Capsules shelf-stable 2+ years.

06

Regulatory status

Classified as a dietary supplement in the US - no prescription required. Widely available. No FDA-approved medical indication.

Put it to work

Calculate, log & track

Open DIM (Diindolylmethane) straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.

Open DIM (Diindolylmethane) in the app →

Go deeper

The guide & community

The complete DIM (Diindolylmethane) walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.

Join the community ↗
Open in app Community