The top three most effective plants for treating covid-19 included licorice root, (Glycyrrhiza glabra) chicory root, (Cichorium intybus) and hibiscus flowers (Hibiscus sabdariffa). Licorice root has history of effectiveness against multiple viruses. In randomized, controlled trials, licorice root also demonstrated both a reduction of mortality for covid-19 patients and broad spectrum anti-viral activity against various causative agents.
The individual compounds with the greatest anti-inflammatory enrichment included
quercetin, ursolic acid, kaempferol, isorhamnetin, luteolin, glycerrhizin, and apigenin.
I think I have a couple bottles of over the counter
Quercetin.
https://www.dcclothesline.com/2021/05/14/medicinal-herbs-effectively-treat-thousands-of-covid-19-patients-in-chinese-hospitals/