Short answer

We found no direct interaction between DIM and Quercetin in the sources below, but they share a caution.

Both may change how your body processes some prescription medicines.

DIM (diindolylmethane)

What it is: A compound formed from vegetables like broccoli and cabbage, sold for estrogen balance.

What the research says: It changes how estrogen is broken down, and lab studies suggest anticancer effects, but human data are limited. There's no evidence for 'detox' claims.

Cautions

• Not for pregnancy, trying to conceive or breastfeeding, because of possible hormone effects.
• Rare reports include vision problems after very high use, and rash.

Medicines to check

• Birth control pills: check with a clinician first
• Many prescription drugs processed by the liver: DIM may make them less effective

In Holitro: DIM (300 mg per capsule)

Source: Memorial Sloan Kettering Cancer Center, About Herbs: Diindolylmethane (updated December 2023)

Quercetin

What it is: A plant compound found in apples, onions and tea; the most common flavonoid in the diet.

What the research says: It hasn't been shown to treat any disease. Its anti-inflammatory effects come from lab studies; in athletes, any performance benefits were small.

Cautions

• No side effects were seen in athletes taking about 1,000 mg a day, but it hasn't been studied enough to know it's safe.

Medicines to check

• Some prescription drugs processed by the liver: it may increase their side effects (lab data)
• Losartan (a blood-pressure drug) and tamoxifen: animal or lab data only

In Holitro: Quercetin (500 mg per capsule)

Sources: Memorial Sloan Kettering Cancer Center, About Herbs: Quercetin (updated October 2023); NIH Office of Dietary Supplements: Dietary Supplements for Exercise and Athletic Performance (updated March 2021)

Check with your doctor or pharmacist, especially if you take medication.

Check your stack — free

Educational information only, not medical advice. This reflects general ingredient overlap, not a personalized safety review. Always check with your doctor or pharmacist before combining supplements, especially if you take medication, are pregnant or nursing, or manage a health condition. These statements have not been evaluated by the FDA.