Quercetin

Active
Good
Low nutritional value

Last updated: February 11, 2026

Table of Contents

Quick Summary

Quercetin A plant-derived flavonoid (antioxidant) found naturally in apples, berries, and leafy greens. Used in supplements for its anti-inflammatory and antihistamine properties.

Category
Active
Common In
Joint supplements, calming treats, specialty formulas
Also Known As
flavonoid quercetin, plant flavonoid
Watts Rating
Good ✓

What It Is

A plant-derived flavonoid (antioxidant) found naturally in apples, berries, and leafy greens. Used in supplements for its anti-inflammatory and antihistamine properties.

Compare to Similar Ingredients

Why It's Used in Dog Products

Manufacturers include quercetin in dog food, treats, and supplements for several reasons:

Quality Considerations

When evaluating quercetin in dog products, it's important to understand clinical evidence, appropriate dosing, and targeted health benefits. This ingredient's quality and appropriateness can vary significantly based on sourcing, processing, and the specific formula it's used in.

Quality Note

Quercetin is generally recognized as safe but has low bioavailability when consumed orally. Some supplements combine it with bromelain to improve absorption. Evidence for effectiveness in dogs is limited but promising for allergies and inflammation.

Potential Concerns

While quercetin can be appropriate in dog nutrition, pet owners should be aware of efficacy, quality of source material, and potential interactions with medications. Individual dogs may respond differently to the same ingredient based on their health status, age, and sensitivities.

Watts' Take

Promising natural alternative to pharmaceutical antihistamines for dogs with allergies. Most effective when combined with absorption enhancers like bromelain or vitamin C. Generally safe with few side effects reported.

Frequently Asked Questions

Is quercetin safe for dogs?

Yes, quercetin is safe for dogs when used appropriately in properly formulated dog food. As with any ingredient, individual dogs may have sensitivities, so monitor for any adverse reactions when first introducing products containing this ingredient.

What does quercetin do in dog products?

A plant-derived flavonoid (antioxidant) found naturally in apples, berries, and leafy greens. Used in supplements for its anti-inflammatory and antihistamine properties. Dog food manufacturers include this ingredient to provide natural antihistamine that may reduce allergic reactions and provide powerful antioxidant that combats free radicals.

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