antioxidant · for chronic inflammation
Quercetin
Steadies the immune cells that release histamine and other inflammatory chemicals.
Say that in clinical terms
Stabilizes mast cells, inhibits LOX and COX pathways, reduces histamine release.
How strong is the research?
Strong evidence
Only one study
2 papers read, 1 supporting.
Who was studied: The cited source is unrelated to quercetin. Real trials enrolled adults with raised inflammation markers.
How much to take
daily
500–1000 mg
Divide into 2-3 doses for better absorption. Take with vitamin C.
Before you take it
- No NIH ODS Tolerable Upper Intake Level (UL) has been established for quercetin; doses above 1 g/day have been associated with adverse effects including headache and tingling in human studies
- Potential nephrotoxicity at very high doses documented in animal models; clinical significance in humans at typical supplemental doses (500–1000 mg/day) is not well established
- Quercetin inhibits CYP3A4, CYP2C8, CYP2C9, CYP1A2, and P-glycoprotein — clinically significant drug interaction risk with warfarin, cyclosporine, CYP3A4-metabolized statins (e.g., simvastatin, lovastatin), digoxin, and other drugs with narrow therapeutic windows
- Drug interaction with quinolone (fluoroquinolone) antibiotics: quercetin can impair antibiotic absorption — separate dosing by at least 2 h before or 4–6 h after the antibiotic
- Insufficient safety data in pregnancy and lactation; avoidance is generally recommended until more evidence is available
- Standard quercetin aglycone has approximately 1–2% oral bioavailability; more bioavailable forms exist (isoquercetin, quercetin-3-glucoside, quercetin phytosome) but most commercial products do not specify the form, making dose-to-effect extrapolation unreliable
What we make of it
The citation is a comment piece about organic food.
The detail
The identifier resolves to a 2020 comment article comparing organic and conventional food. It has nothing to do with quercetin or inflammation, so none of the numbers attached to this claim can be trusted.