What Is Diindolylmethane (DIM)? 6 Benefits & Side Effects

Benedict Ang, CPT, PN1-NC
Published by Benedict Ang, CPT, PN1-NC | Staff Writer & Senior Coach
Last updated: December 8, 2023
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Many testosterone boosters contain a natural compound known as diindolylmethane or DIM for short.

It’s often added to male supplements because it promotes a healthy hormonal balance that leads to optimal testosterone levels.

I’ve invested hundreds of hours into researching DIM to understand better its mechanism, as well as benefits and potential side effects.

Finally, I’ve compiled and distilled all the data, and here’s everything you need to know about this compound.

Quick Summary

  • DIM aids in balancing hormones, particularly by managing estrogen levels and supporting testosterone activity.
  • DIM supplements contribute to maintaining healthy testosterone levels, improving prostate health, and may aid in cancer prevention.
  • According to the National Institute of Health, only about 2% of total testosterone in the body is free and active, which DIM helps to increase.
  • From my perspective, DIM's role in supporting hormonal balance and its potential in cancer prevention make it a noteworthy supplement for health-conscious individuals.

What Is Diindolylmethane (DIM)?

hands filled with pills and DIM

DIM is a compound produced when you digest cruciferous vegetables such as broccoli, Brussels sprouts, and cauliflower, among others.

Diindolylmethane (DIM) supports estrogen metabolism, prostate health, and balances estrogen levels by reducing its excess production.

These veggies have two key compounds: DIM and indole-3-carbinol (I3C). Cooking transforms I3C into DIM, while eating them raw or lightly cooked activates enzymes that help DIM absorption.

According to the National Instute of Health, DIM is known to have potent cancer chemopreventive properties and is currently being investigated for its use in prostate cancer prevention and treatment [1].

Yet, getting DIM's benefits from veggies alone is tough; you'd need several servings daily. To solve this, companies offer absorbable DIM supplements.

How Does DIM Affect Testosterone Activity?

man looking at supplement while seated at the gym

From my own journey with DIM supplements, I've noticed a significant boost in my energy and muscle-building efforts.

Echoing the National Institute of Health's findings, DIM has been a game-changer in maintaining my free testosterone levels [2].

This type of testosterone isn't bound by SHBG, the carrier protein. It's the free testosterone that really gets into your muscle cells, fat cells, and brain, which is what you want for those muscle-building and cognitive benefits.

According to MayoClinic,  free testosterone is only about 2% of your total testosterone [3].

“Once absorbed, DIM is uniquely active in promoting healthy estrogen metabolism and improving symptoms of estrogen-related imbalance in both men and women.”

- Michael Zeligs, M.D., Founder & CEO of BioResponse Nutrients

DIM is a game-changer for boosting testosterone by increasing 'good' estrogen metabolites in your body.

Acording to NIH, these good guys latch onto SHBG, leaving more free testosterone available for you [4].

The Benefits of DIM Supplements for Men

feet and weighing scale and a man giving thumbs up

Maintains Healthy Testosterone Levels

According to NIH, DIM inhibits the production of an enzyme called aromatase, which converts testosterone to estrogen [5].

The good estrogen metabolites promoted by DIM are known to displace testosterone from SHBG, setting it free and letting it do its work in your body.

Cancer Prevention

As per a 2016 study from the National Library of Medicine, a high intake of cruciferous vegetables reduces the risk of certain cancers. The exact mechanism is unknown, but indole-3-carbinol is believed to be partly responsible for this effect [6]. Also, DIM positively affects estrogen metabolism relating to breast cancer risk.

In test-tube and animal studies by NIH, the dietary supplement has been shown to help prevent the growth and proliferation of breast cancer cells [7].

Testosterone Boosters Containing DIM We Have Reviewed:

Improves Prostate Health

man in boxers brief giving thumbs up

Having used DIM supplements myself, I've felt more confident about my prostate health. They're not just a theoretical defense against prostate enlargement and cancer.

In my case, they've been a proactive measure against prostatic intraepithelial neoplasia (PIN) – a precursor to prostate cancer. It's reassuring to know that I'm taking steps to address these issues before they escalate.

According to an NIH study over 12 months found that guys with serious PIN issues saw major improvements in their prostate health by popping 900 mg of DIM every day [8].

Plus, DIM helps lower the production of PSA, that protein that, when high, is a red flag for prostate cancer.

Reduces Night-Time Urination in Older Men

DIM might also result in fewer trips to the bathroom at night in older men concerning its effects on the prostate. According to ScienceDirect, it also exhibits anti-inflammatory properties and has been shown to be beneficial in reducing the risks caused by cardiovascular diseases [9].

Supports Weight Loss

According to NIH, an imbalance in estrogen is linked to an increased risk of weight gain in both men and women [10]. DIM also stimulates fat breakdown and inhibits the formation of new fat cells.

It has been shown to increase “good” estrogen metabolites that support more efficient fat metabolism by promoting the active release of stored fat for improved energy during exercise. However, more human studies are needed.

What Are the Side Effects of DIM Supplements?

man holding his head in pain and another person using the toilet

Not much is out there about DIM supplement side effects since human research is kinda limited.

But from what we do know, DIM seems safe – it's not toxic and doesn't bring any major side effects to the table.

According to NIH, the most common side effects include [11]:

  • Increase in bowel movements
  • Dark urine
  • Gas
  • Headaches

Less common side effects include:

  • Diarrhea
  • Vomiting
  • Nausea
  • Skin rash

Individuals with hormone-sensitive cancers or those undergoing hormone therapies should steer clear of DIM supplements because they interact with estrogen levels.

But no matter your medical history or condition, it’s essential to talk to your doctor before taking DIM supplements.

How Much DIM Should You Take?

man drinking meds

Typical DIM doses range from 108-900 mg daily, based on cancer and prostate enlargement studies [12]. Always check with your healthcare provider for the right DIM dose for your health, age, and purpose.

When dealing with estrogen levels and imbalances, weigh the pros and cons of using DIM with hormone replacement therapy.

While DIM shows promise, more research is needed, especially for those with hormone-sensitive conditions. Consulting a healthcare expert before starting DIM is crucial to prevent interactions and manage symptoms like mood swings effectively.


What Happens When You Start Taking DIM?

When you start taking DIM, your hormones will be balanced, and you will reduce the likelihood of certain types of cancers. DIM also has antioxidant activity that protects the body from free radical damage, aids in weight reduction, boosts energy, improves mood, enhances memory, and promotes strong bones and joint health.

Who Should Avoid DIM?

Pregnant or nursing women, those who are in birth control pills, and women planning to get pregnant should avoid DIM, as it has hormone modulation effects.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9962283/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4759426/
  3. https://www.mayocliniclabs.com/test-catalog/overview/83686
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5510446/
  5. https://pubmed.ncbi.nlm.nih.gov/22075942/
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5059820/
  7. https://pubmed.ncbi.nlm.nih.gov/25048790/
  8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818865/
  9. https://www.sciencedirect.com/science/article/abs/pii/S0146280623000816
  10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5835337/
  11. https://pubmed.ncbi.nlm.nih.gov/22075942/
  12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818865/
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