Quercetin reduces COVID-19 risk: real-time meta-analysis of 9 studies (Version 23)

Significantly lower risk is seen for mortality, ICU admission, hospitalization, recovery, cases, and viral clearance. 9 studies from 7 independent teams in 5 countries show significant benefit.

Meta-analysis using the most serious outcome reported shows 35% [15‑51%] lower risk. Results are similar for higher quality studies and better after excluding studies using combined treatment. Currently all studies are RCTs.

Control Quercetin

Currently there is limited data, with only 841 patients in trials to date.

Studies typically use advanced formulations for greatly improved bioavailability.

No treatment is 100% effective. Protocols combine safe and effective options with individual risk/benefit analysis and monitoring. Other treatments are more effective. Dietary sources may be preferred. The quality of non-prescription supplements varies widely1-4. A lipid-optimized formulation may be required for therapeutic concentrations of quercetin. All data and sources to reproduce this analysis are in the appendix.

Other meta-analyses show significant improvements with quercetin for mortality5, ICU admission5,6, and hospitalization5,6.

2 meta-analyses show significant improvements with quercetin for mortality1, ICU admission1,2, and hospitalization1,2.