I3C Explained: Benefits, Sources & Supplements


Indole-3-Carbinol (I3C) is a powerful compound formed when you cut, chew, or cook cruciferous vegetables. It’s formed when an indole glucosinolate called glucobrassicin is broken down.

Why is I3C such a powerful compound? 

For starters, it contains anti-inflammatory and antioxidant properties that lower the risk of several cancer types.1 I3C also has great hormone-balancing effects, especially among women.2 

Specifically, it helps regulate estrogen levels in the body. As a result, it helps people suffering from hormonal imbalances, premenstrual syndrome, or even menopause. 

In this article, we’re diving deep into those benefits, what I3C can do, and everything you need to know about it. 

Man running on a treadmill
I3C is great for hormone balance to get the most out of your workouts.

How I3C Works: Main Benefits 

I3C helps detoxify enzymes in the digestive tract and liver. Its two main uses of I3C in the healthcare industry are: 

  • Preventing cancer: various lab studies suggest I3C may protect against a variety of cancers. More studies are necessary to definitively prove this, though.
  • Treating viral infections: lab studies also the ability to promote immunity and antiviral functions. More studies are also necessary to prove this. 

Studies have also shown I3C to have antimicrobial, anti-inflammatory, and anti-estrogenic effects. Like others, further studies are necessary to 100% prove the above effects. 

Promoting Estrogen Metabolism

I3C improves estrogen metabolism. Estrogen is one of the most critical hormones in the body. It keeps the blood vessels flexible and healthy by protecting them from inflammation. 

You need healthy estrogen metabolism because: 

  • It helps regulate the menstrual cycle. 
  • It helps maintain bone density, which helps reduce the risk of osteoporosis. 
  • It helps prevent bone resorption4, indirectly helping bone formation.

While you may associate estrogen with women’s health, men also rely on this hormone for overall health. Men also produce estrogen — just in smaller amounts. It helps: 

  • Regulate bone growth and brain functions. 
  • Regulate cholesterol levels. 

Without enough estrogen, men can suffer from heart attacks and other cardiovascular issues5. Extremely low estrogen levels can lead to prostate cancer for men and breast cancer for women.

I3C promotes estrogen metabolism, which in turn helps prevent the above risks. 

In recent years, I3C has become a popular supplement for fitness enthusiasts, as faster estrogen metabolism results in a favorable hormone balance in favor of testosterone, which some have found to improve muscle growth10.

Promoting Natural Detoxification 

I3C is also popular for its detoxifying effects. It contains various metabolites, including diindolylmethane (DIM). I3C and DIM help in enzyme production, which involves Phase I and Phase II detoxification processes in the liver. 

These enzymes break down harmful toxins and help the body eliminate them as waste. This supports your body’s natural detoxification processes. 

Because of that, I3C possesses a strong potential to prevent various diseases and inflammation. These include: 

  • Heart diseases
  • Arthritis 
  • Cancer 

With more efficient detoxification processes, your body also prevents cell and tissue damage more effectively. 

Strengthening The Immune System

I3C helps produce antioxidants, allowing it to activate immune cells such as T-cells. Immune cells fight off infections and diseases that enter your body. By activating them, I3C helps strengthen your immune system response. 

Cruciferous veggies — the main source of natural I3C — are also great sources of essential nutrients, such as ascorbic acid. You may know this as Vitamin C, a strong immune system enhancer. 

I3C Sources and Recommended Amount

As mentioned, cruciferous veggies are rich in I3C. These include: 

  • Brussels sprouts 
  • Cabbage 
  • Cauliflower
  • Broccoli
  • Kale 

Eating these veggies is the best and safest way to acquire I3C in your body. But you can also take I3C supplements (a topic we’ll discuss in detail below). 

There are no official “minimum daily amount” recommendations from health experts. It’s the same principle as the saying, “An apple a day keeps the doctor away.” 

Nonetheless, adding I3C-rich food to your daily meal is an excellent way to stay healthy. You can: 

  • Add broccoli to soups, salads, and stir-fries, or steam it as a side dish. 
  • Use cauliflower as a substitute for rice or potatoes since it’s rich in fiber. 
  • Use kale in juices, fruit shakes, or smoothies to hide its bitter taste. 
  • Roast Brussels sprouts with olive oil and seasonings…or enjoy it as a steamed side dish. 

I3C As Nutritional Supplements 

You can also take I3C in the form of nutritional supplements. It’s best to consult with a health professional first to know the right dosage and supplement form for you. 

General guidelines6 from health experts include the following: 

  • Oral supplements: I3C is safe for most people to take orally under medical supervision for up to 400 mg daily.  
  • For children: I3C is possibly safe for children when taken orally under medical supervision. Doses range from 6 to 17 mg per kilogram. 

Because of its various medical effects, I3C in supplement form is popular among fitness enthusiasts. It helps them improve their cardiovascular strength while also maintaining a healthy metabolism and immune system. 

But remember: the right dose of I3C depends on other factors such as your: 

  • Age 
  • Overall health 
  • Other existing conditions 

So always follow directions on product labels and consult with your physician before taking I3C supplements. 

Possible Side Effects

Most people eating I3C-rich food and taking supplements tolerate I3C doses well. However, some side effects have been recorded. 

For starters, some people develop skin irritation problems when taking I3C supplements7. In higher doses, I3C can also cause: 

  • Balance problems 
  • Nausea
  • Tremor 

Moreover, I3C might slow down blood clotting8. Theoretically, it can increase the risk of bleeding among people with bleeding disorders. Still, further research is necessary to confirm these effects. 

Do You Need I3C Supplements? 

Most of the time, you don’t need to take I3C supplements if you’re already consuming plenty of I3C-rich food. 

If you’re a fitness enthusiast, however, taking I3C supplements is generally a good way to enhance your body’s metabolism. 

Tips When Buying I3C Supplements

Before buying I3C supplements, consider increasing your consumption of cruciferous veggies first. 

If you’ve decided to buy I3C supplements, consider the following tips: 

  • Consult with a professional: talk to your dietitian or physician first, especially if you have any underlying health condition or are taking medication. 
  • Choose a reputable brand: buy from brands that follow good manufacturing practices. Look for third-party quality testing certifications to ensure their product’s purity and potency. 
  • Read labels carefully: check important information on the product’s label such as I3C content per serving, suggested dosage, and additional ingredients or fillers. The label should also offer information on where the I3C is sourced whether it’s from cruciferous veggies or synthetic sources. 
  • Consider your goals: increasing your I3C intake is generally a good thing, but what are your goals? Do you wish to support your hormonal balance? Are you trying to improve your fitness routine? Discuss such goals with your healthcare professional to know if I3C is the appropriate choice. 
  • Be patient: many nutritional supplements take time to show noticeable effects. The same goes for I3C. Give it time to work, and remember that your body may not react as fast as others to I3C supplements. 
  • Monitor side effects: once you’ve started taking I3C supplements, be on the lookout for any side effects. Digestive discomfort and urine discoloration are some common side effects9. If you experience them and other adverse effects, discontinue using the supplements and consult with your healthcare provider. 
  • Combine with a balanced diet: take supplements in conjunction with a healthy diet. This allows you to support your overall health in a more well-rounded manner. Do not use supplements to replace proper meals and good food. 

Final Thoughts 

Overall, I3C is a powerful substance that offers plenty of unique benefits. These benefits include better metabolism, improved detoxification, and a stronger immune system. Because of that, I3C is perfect for people trying to improve their overall wellness. 

Eating cruciferous vegetables offers an easy and natural way to acquire higher levels of I3C. However, you can also take them in the form of supplements but always talk to your healthcare professional to know if I3C supplements are appropriate for you.


1. Traka M. Chapter nine-health benefits of glucosinolates. Advances in Botanical Research. 2016;80:247-279 

2.  https://pubmed.ncbi.nlm.nih.gov/7827590/ 

3.  Enriquez J, Velazquez-Cruz R, Parra-Torres A, et al. The anti-estrogenic activity of indole-3-carbinol in neonatal rat osteoblasts is associated with the estrogen receptor antagonist 2-hydroxyestradiol. J Endocrinol Invest. 2016 Oct;39(10):1149-58.

4.  Annu. Rev. Food Sci. Technol. 2023. 14:347–66 Indole-3-Carbinol: Occurrence, Health-Beneficial Properties, and Cellular/Molecular Mechanisms

5. Pérez-López, et al Gender Differences in Cardiovascular Disease: Hormonal and Biochemical Influences

6.  https://www.webmd.com/vitamins/ai/ingredientmono-1027/indole-3-carbinol 

7.  McAlindon TE, Gulin J, Chen T, Klug T, Lahita R, Nuite M. Indole-3-carbinol in women with SLE: effect on estrogen metabolism and disease activity. Lupus. 2001;10(11):779-783.  (PubMed)

8.  https://annarborholistichealth.com/2015-4-21-dim-diindoly-methan-for-natural-protection-from-estrogens-effect/ 

9.  Effect of diindolylmethane supplementation on low-grade cervical cytological abnormalities: double-blind, randomized, controlled trial (PubMed

10. https://provita-nutrition.ca/blogs/blog/i3c-good-for-testosterone

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