Studies that shows Quercetin's effectiveness
Inhibition of SARS-CoV 3CL protease by flavonoids
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6882434/
Quercetin: A Promising Treatment for the Common Cold
https://www.longdom.org/open-access/quercetin-a-promising-treatment-for-the-common-cold-2329-8731.1000111.pdf
Coronavirus disease 2019 (COVID-19): first indication of efficacy of Gene-Eden-VIR/Novirin in SARS-CoV-2 infection
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146686/
Quercetin, Inflammation and Immunity
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808895/