500–1,000 mg/day, often with vitamin C for better absorption.
Lowers blood pressure somewhat, more in hypertensive people and at doses ≥500 mg.
View the study (meta-analysis) →Stabilizes mast cells in the lab; clinical evidence is weak.
No reliable benefit.
*⏱ 2 min read
Quercetin is a bioactive compound with potent antioxidant and anti-inflammatory properties; it belongs to the flavonoid class of plant polyphenolic compounds and is found in a wide variety of fruits and vegetables, especially red and yellow onions, capers, apples, blueberries, and peppers; it is the most abundant flavonoid in the human diet, although its amount in fruits and vegetables can vary widely depending on the type of food, growing conditions, and method of preparation.
Research indicates that quercetin may relieve chronic health conditions such as hypertension, neurodegenerative diseases, arthritis, and lung and kidney diseases, and may be beneficial in combating age-related diseases; although much of the research on quercetin has been done in animals, some clinical trials have been conducted and others are ongoing, making it one of the most studied polyphenols and one with the greatest therapeutic potential demonstrated in preclinical models.
One of the most exciting advances in the biology of aging is the discovery that the accumulation of senescent cells, cells that have stopped their life cycle and secrete proinflammatory molecules, drives many age-related diseases; quercetin was one of the first senolytic compounds discovered and may have a beneficial effect against aging, although it generally needs to act together with another agent to eliminate all types of senescent cells and is typically administered with dasatinib, an anticancer drug approved for certain types of leukemia.
Studies in animal models of premature aging have shown that eliminating senescent cells with a combination of dasatinib and quercetin improves physical health, delays the onset of age-related diseases, and extends lifespan; a pilot trial in humans with diabetic kidney disease showed that the combination of dasatinib plus quercetin for 3 days produced significant reductions in senescent cells in adipose tissue, reducing senescence-associated molecules and improving regulatory mechanisms in fibroblasts, which represents the first evidence in humans of the senolytic effect of this combination.
Quercetin has broad-spectrum antiviral properties demonstrated in vitro against multiple viruses including SARS-CoV-2, influenza H1N1, respiratory syncytial virus, and others; a randomized study of 1,002 adults found that 12 weeks of quercetin at doses of 500-1,000 mg per day significantly reduced the frequency and duration of upper respiratory tract infections and days of illness with complications in adults at elevated risk of infection, although these results require replication before firm public health recommendations can be made.
Information, not medical advice. Scientific evidence reflects the quality of the studies.