Diindolylmethane
What the trials found
Diindolylmethane has not been shown to improve healthy ovulation signals in women; not enough research establishes meaningful benefits across its broader supplement claims.
- 2 papers
- 1 of 8 outcomes
- 1 severe
Risk, worst reported severity
- tumor promotion (colon and liver) in animal studies; potential carcinogenesis concerns severe
- Myocardial hypoxia on ECG moderate
- cyclosporine moderate
- indinavir moderate
What diindolylmethane actually does
Reproductive hormones help regulate ovulation, menstrual cycles, and the chance of pregnancy. 28560655
| Outcome | Effect | Evidence | Dose | Time | Rank |
|---|---|---|---|---|---|
| Early research 1 | |||||
| Support fertility hormone levels Not enough research Reproductive hormones help regulate ovulation, menstrual cycles, and the chance of pregnancy. | | 1 RCT 1 papers · n=97 | 150 mg | 52 wk | — |
Effect tiers come from native-unit MCID where available, Cohen's d otherwise.
Dose, timing & forms
How much
The available consumer-focused evidence uses 150 mg daily in a long-term protocol examining estrogen-related measures. 1 That is a study dose, not an established target for hormone support, because the outcome evidence remains too limited to show a reliable benefit. 1 Avoid escalating the dose in pursuit of stronger effects. Higher intake does not solve the current evidence gap. 12
When and how long
Take DIM consistently rather than using it only around a menstrual cycle phase, since the longer protocol followed daily use across a year. 1 The evidence does not establish a best time of day or a meaningful advantage for splitting the dose. Taking it with a meal is a practical choice if nausea occurs, but this is tolerability guidance rather than a proven way to improve results. 1
Forms & standardisation
Look for a product that clearly states the amount of diindolylmethane per serving, rather than relying on vague claims about broccoli extracts. The human trial evidence concerns supplemental DIM, not simply a cruciferous vegetable powder. 12 A standardized label does not prove that a product will improve hormone outcomes, because that clinical question remains unanswered. 1
Studied range, by outcome
| Outcome | Studied range | Median effective | Duration | Evidence |
|---|---|---|---|---|
| Support healthy estrogen function | 150 mg | — | 52 wk | 1 paper |
Adverse events and drug interactions
Safety events
Drug interactions
What this is and how it works
- One randomized trial (n=97) assessed ovulation-related signals, but no reliable effect estimate established a benefit. 1
- Two papers reviewed here spanned eight outcomes, with evidence concentrated in one early research tier.
- Human evidence remains limited to narrow populations and cannot establish DIM’s effects on estrogen or fertility outcomes.
Diindolylmethane, usually called DIM, is a compound your body can form from indole-3-carbinol, a natural component of cruciferous vegetables such as broccoli, cabbage, and Brussels sprouts. Supplements deliver DIM in a far more concentrated form than food typically does. 2
DIM interacts with the aryl hydrocarbon receptor, a cellular switch that changes activity in genes involved in processing hormones and foreign compounds. Think of it as changing the routing rules at a sorting center, not as directly raising or lowering estrogen itself. 2 Human research shows changes in estrogen-metabolite patterns in some settings, but it has not established a meaningful improvement in estrogen function or ovulation signals. 1
Bottom line
DIM is best viewed as an early-research supplement, not a proven estrogen or fertility tool. People looking for support for ovulation signals or estrogen function should not expect established results from it yet. 1 Given reported safety concerns and interaction potential, avoid self-starting DIM if you use prescription medicines or have a complex health history.
Common questions
Does DIM balance estrogen?
How long does DIM take to work?
Is DIM the same as eating broccoli?
Sources
Sources
Generated August 27, 2026