HerbBB Back to home
繁中简中EN
ADVERTISEMENT
Explore ingredients / Plant extracts

Plant extracts · in-depth review

Quercetin

Quercetin

Quercetin is a flavonol common in onions and apples. Supplements are often the dihydrate or a phospholipid complex, used for seasonal nasal allergy and low-grade inflammatory signaling. Oral absorption is limited; take with food.

Also known asQuercetinquercetinquercetin dihydrate
Health goalsAllergic RhinitisUpper Respiratory SupportSystemic Micro-inflammationSkin Hydration
Related diseasesAllergic rhinitis
Related symptomsNasal congestion
Disease classesDiseases of the blood or blood-forming organs and certain immune disordersDiseases of the respiratory system
01

Why supplement?

✓

Seasonal nasal allergy

Quercetin can stabilize mast cells and affect histamine-release paths. Seasonal allergic-rhinitis trials often use about 500 mg daily across a pollen season on runny-nose and itch scores. The effect is nutritional support over weeks. Free aglycone absorbs poorly; some trials use phospholipid carriers to raise blood exposure.

✓

Flavonol oxidative stress

Phenolic hydroxyls can scavenge radicals and modulate Nrf2-related enzymes. The setting is low-grade systemic inflammation; oxidative markers usually change only after weeks. Human lipid and glucose results are mixed and still rest on blood markers. Diet mostly supplies glycosides in onion skins; supplements are the aglycone or a complex.

ADVERTISEMENT
02

How to take it

With foodTake with or after food; phospholipid carriers still prefer a full stomach
Best timeMorning or midday

Food improves tolerance; follow the label for phospholipid carriers, and do not stack several high-dose flavonoid products on your own.

General wellnessTypical daily intake for general wellness: quercetin often 500–1,000 mg with food; convert phospholipid carriers as labeled
Specific needsTypical adult daily safety upper limit is about 1,200 mg; people with kidney disease or on medicines should ask a clinician first, and do not exceed this on your own long term.

How oftenGenerally can be used daily and adjusted to individual need.

03

What to watch

Cautions

Ask a doctor first if you have kidney disease, take cyclosporine or other CYP3A4-metabolized drugs, take anticoagulants, or are pregnant or breastfeeding.

Common side effects

· Mild stomach discomfort or headache can occur.

Rare but important

· High doses have uncommon reports of kidney-function changes; stop and seek care if discomfort persists.

Long-term dependenceNo typical addiction evidence; long-term overuse on your own is not advised.

Medical disclaimerThis page is compiled by the HerbBB editorial team for general health information only. It is not a substitute for advice from a doctor, pharmacist, or other qualified clinician. If you have a health condition, take medicines, or are pregnant or breastfeeding, speak with a professional first.