What is it used for?
Source of (an) antioxidant(s)/Provides (an) antioxidant(s) [Source note 2].
Source of (an) antioxidant(s)/Provides (an) antioxidant(s) that help(s) fight/protect (cell) against/reduce (the oxidative effect of/the oxidative damage caused by/cell damage caused by) free radicals [Source note 3].
Helps to support/promote healthy estrogen metabolism/balance (Reed et al. 2005; Bell et al.2000; Wong et al. 1997; Bradlow et al. 1994).
Helps reduce the severity and duration of symptoms associated with recurrent breast pain (cyclical mastalgia) [Source note 4].
Note: If 3,3'-Diindolylmethane (DIM) is combined with other active ingredients with antioxidant properties at Class II and III, there is an option to use the claim in plural. The singular should be used when the product only contains one chemical substance as the active ingredient associated with this claim.
What this guide covers
The solidus (/) indicates that the terms and/or statements are synonymous. Either term or statement may be selected by the applicant on the label.
Restrictions when this reference is combined with other references (source review category II and III):
Specific combination rules apply to active ingredients with estrogenic (e.g., red clover isoflavone extract, soybean extracts and isolates and dong quai - Angelica sinensis) or anti-estrogenic effects [e.g., indole-3-carbinol (I3C) and, diindolylmethane (DIM)]. Consult the reference combination guide for more information.
Who does this guide cover?
Adults 18 years and older
How is it taken?
Oral
Which forms are covered?
this reference excludes foods or food-like dosage forms as indicated in the Compendium of references Guidance Document.
Quantities
Antioxidant
Not to exceed 200 milligrams of DIM, per day (Laidlaw et al. 2010; Reed et al. 2008; Naik et al. 2006; Reed et al.2005; McAlindon et al. 2001; Bell et al. 2000; Wong et al. 1997; Bradlow et al. 1994).
Healthy Estrogen Metabolism; Recurrent Breast Pain
60 - 200 milligrams of DIM, per day [Source note 5].
How is it used?
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
How long is it used?
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
Warnings and precautions
Products making healthy estrogen balance/metabolism claim
Ask a healthcare professional before use to exclude the diagnosis of a serious cause of hormonal imbalance [Source note 6].
Recurrent breast pain
Ask a healthcare professional if symptoms persist or worsen.
Products providing 6 milligrams or more of DIM, per day
Ask a healthcare professional before use if you are taking medications or supplements [Source note 7].
Ask a healthcare professional before use if you are attempting to conceive [Source note 8].
Stop use and ask a healthcare professional if you develop liver-related symptoms (e.g., yellowing of the eyes and/or skin, dark urine, abdominal pain, jaundice) or symptoms of low estrogen [Source note 9].
Products providing 6 milligrams or more of DIM, per day
All subpopulations or Female subpopulation only
Ask a healthcare professional before use if you have a liver disorder or symptoms of low estrogen such as joint pain, mood changes, changes in libido, hot flashes, night sweats, vaginal dryness or irregular menstruations [Source note 10].
Male subpopulation only
Ask a healthcare professional before use if you have a liver disorder or symptoms of low estrogen such as joint pain, mood changes or changes in libido [Source note 11].
When should it be avoided?
All products
Do not use if you are pregnant or breastfeeding (Reed et al. 2006; Michnovicz et al.1997).
Possible side effects
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
Storage
Must be established in accordance with the requirements described in the applicable product regulations.
Preparation details
Ingredient identity, preparation requirements, and other details that define the scope of this guide.
Ingredients and preparations
| Proper name(s) | Common name(s) | Source information / Source ingredient(s) | Source information / Source material(s) | Source information / Part(s) | Source information / Preparation(s) |
|---|---|---|---|---|---|
|
| N/A |
| Whole plant | Isolate |
|
| 3,3'-Diindolylmethane | N/A | N/A | Synthetic |
References: Proper names: NIH 2024; Common names: NIH 2024; Source information: Pradhan et al. 2005; Jongen 1996; Kwon et al. 1994; Bradfield and Bjeldanes 1991.
Other ingredients
Must be chosen from the current source ingredient database and must meet the limitations outlined in the database.
Preparation and quality requirements
The finished product specifications must be established in accordance with the requirements described in the source authority source’s product quality guidance.
The active ingredient must comply with the requirements outlined in the source ingredient database.
Guide change history
Updates to this SupplementSafety.org guide.
Minor updates
Updated guide wording, organization, and source presentation. Added our editorial change history.
Initial release
Initial SupplementSafety.org guide prepared from source reference material.
Validation: Not yet completed. Editorial updates do not constitute clinical validation.
Sources
Source information
This guide organizes source material about uses, preparations, amounts, and precautions. Read the conditions alongside each statement; the information may apply only to particular preparations or populations.
The source document includes supporting references. We have not independently summarized or assessed every cited study for this guide.
- Source document version
- May 29, 2026
- Source captured
- Aug 15, 2026
- Editorial work
- Editorial preparation. Independent clinical review has not been recorded for this guide.
Full citations are available through the link above. Verification is required to open them; reading this guide does not require verification.
Taking a medication too?
Explore our supplement–medication interaction checker. Its coverage and review status are shown with the results; a missing finding does not establish that a combination is safe.