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Quercetin Ingredient Notes
Quercetin is a flavonoid found in foods such as onions and apples. Food amounts and concentrated supplements differ, as do plain quercetin and formulated complexes.
Quercetin is a flavonoid found in foods such as onions and apples. Food amounts and concentrated supplements differ, as do plain quercetin and formulated complexes.
Community experiences
Selected positive personal experiences from external communities, edited and summarized. These accounts do not establish effectiveness.
A contributor who reported allergies to dust, mold and pollen wrote that several months of quercetin use helped them manage persistent nasal congestion and the discomfort of mucus draining down the back of the throat. They described changes experienced over months, rather than just an initial impression after brief use. They did not disclose the product formula, dose or medicines used alongside it, so this is not confirmation of an allergy treatment effect or a substitute for medication.
Experience shared by external community contributor A
This page is for general reference only and is not medical advice, diagnosis, treatment, or prescription. Ask a qualified professional if you need medical advice or diagnosis.
What is Quercetin?
Quercetin is a flavonoid found in foods such as onions and apples. Food amounts and concentrated supplements differ, as do plain quercetin and formulated complexes.
On Supplecipe, you can search iHerb products that mention Quercetin and compare single-ingredient products against broader supplement blends.
Evidence and limitations
A four-week placebo-controlled trial in 66 Japanese adults with pollen-allergy symptoms found improvements in some measures, including itchy eyes, with a specific quercetin phytosome. The small, short study does not establish the same effects for all forms or replacement of allergy medicines.
Yamada et al. (2022): quercetin allergy trial · MSK: Quercetin
Forms and other names
Quercetin phytosome is a formulated complex containing other materials, not simply another name for pure quercetin. Do not count its entire weight as quercetin.
Related ingredients
Related reading, not a recommendation to combine supplements.
Side effects and cautions
An elevated INR has been reported in a person taking warfarin after adding quercetin. Check with a professional if taking anticoagulants or other medicines. During cancer treatment, discuss interactions with the treatment team before adding supplements.
Yamada et al. (2022): quercetin allergy trial · MSK: Quercetin
How to compare iHerb products
- Distinguish total phospholipid-complex weight from the amount of quercetin supplied. Check individual bromelain, vitamin C or other added amounts, the formulation and serving size.
- Look for form, serving size, extra ingredients, allergens, and whether the product is a single ingredient or a blend.
- Compare brand, price per serving, ingredient form, and single-ingredient versus complex products.
- Use the search button below to compare iHerb products that mention this ingredient.
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