Short answer

We found no documented interaction between Carnitine and Quercetin in the sources below. That isn't proof the combination is right for you: check each one's cautions, and ask your pharmacist if you take medication.

Carnitine

What it is: A nutrient the body makes and gets from meat; it helps turn food into energy.

What the research says: Healthy people make all they need. Results for dementia and other conditions are mixed.

Cautions

• 3 g a day or more can cause nausea, cramps, diarrhea and a fishy body odor.
• High amounts may cause muscle weakness in kidney disease and raise seizure risk in people with seizure disorders.

Medicines to check

• Some anti-seizure medicines (phenobarbital, valproic acid) and long-term use of some antibiotics can lower carnitine levels

In Holitro: Carnitine (500 mg per capsule)

Source: NIH Office of Dietary Supplements: Carnitine: Fact Sheet for Consumers (updated May 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.