Quercetin
Immune · Flavonoid
Tier C+
What this is
Native quercetin has <1% oral bioavailability — most trials use large doses or enhanced formulations. The 'zinc ionophore' claim popularized during COVID was based on weak in vitro data. Reasonable adjunct for mast cell activation / allergic phenotypes.
Mechanism
Flavonol ubiquitous in plants (onions, apples, capers); broad antioxidant; mast cell stabilization; proposed zinc ionophore activity (controversial claims during COVID); mTOR/AMPK modulation
Dose & route
500-1000 mg/day; phytosome form at lower doses
Citations
- https://pubmed.ncbi.nlm.nih.gov/27187333/
- https://pubmed.ncbi.nlm.nih.gov/31261295/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7230406/
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This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.