Quercetin
FlavonoidAlso known as: Quercetin dihydrate · Quercetin phytosome
A plant flavonoid with anti-inflammatory, antioxidant, and senolytic properties. Studied for immune function, cardiovascular health, and as part of senolytic protocols (with dasatinib). Poor bioavailability requires enhanced formulations.
How expert claims hold up
13 of 26 claims assessed2 of 13 assessed claims supported or partially supported by published research
Evidence Summary
Quercetin is a naturally occurring flavonoid polyphenol found in common foods such as onions, capers, apples, and kale, and has been an active subject of scientific research for decades. The available literature spans reviews, systematic reviews, and meta-analyses across a wide range of health domains — including cardiovascular health, inflammation, allergy, bone metabolism, blood sugar regulation, exercise recovery, and cognitive aging. However, the breadth of this research has not yet translated into consistent, high-quality clinical evidence for most of these claimed benefits, with the expert claim comparison finding that 11 of 13 evaluated claims carry insufficient evidence to support them in humans.
Read full evidence summary →Top studies
Improving quercetin bioavailability: A systematic review and meta-analysis of human intervention studies.
Improving quercetin bioavailability: A systematic review and meta-analysis of human intervention studies.
The Effects of Quercetin Supplementation on Blood Pressure - Meta-Analysis.
The Effects of Quercetin Supplementation on Blood Pressure - Meta-Analysis.
Expert Mentions
All 26 mentions"For daily anti-inflammatory and antioxidant support, lower doses of 250 to 500 milligrams of a bioavailable formulation are more typical."
For daily anti-inflammatory and antioxidant support, lower doses of 250 to 500 milligrams of a bioavailable formulation are more typical.
The 10 provided studies — spanning reviews, systematic reviews, and one meta-analysis — contain no extractable key findings, populations, or limitations as presented, making direct comparison impossible. None of the abstracts or summaries specify dosing ranges of 250–500 mg for bioavailable quercetin formulations in the context of daily anti-inflammatory or antioxidant support. While several studies (e.g., PMID 26999194, 38258783, 35948195) appear thematically relevant to quercetin's anti-inflammatory and antioxidant effects, the absence of reported data precludes any determination of whether the claimed dose range is supported, contradicted, or nuanced by this literature.
"For daily anti-inflammatory and antioxidant support, lower doses of 250 to 500 milligrams of a bioavailable formulation are more typical."
For daily anti-inflammatory and antioxidant support, lower doses of 250 to 500 milligrams of a bioavailable formulation are more typical.
Key findings
- ·Quercetin is a well-characterized flavonoid polyphenol with a long research history, found naturally in onions, capers, apples, and kale.
- ·A meta-analysis suggests quercetin supplementation may have a modest effect on blood pressure, though the clinical significance is unclear without access to full study data.
- ·Quercetin's bioavailability is recognized as a major obstacle; a systematic review and meta-analysis specifically examined strategies to improve absorption in humans.
Evidence gaps
- ·There is a significant lack of large, well-designed randomized controlled trials in humans testing quercetin's efficacy for most of its proposed health benefits across specific populations.
- ·Optimal dosing, supplement formulation, and delivery methods for meaningful human bioavailability have not been established, limiting the translation of laboratory findings to real-world supplementation.
- ·Long-term safety data in humans is sparse, and it remains unclear whether chronic quercetin supplementation at commonly marketed doses is safe across diverse populations, including those on medications.