Here's another investigation of a popular supplement as protective against Covid-19--I've been taking Ginko Biloba for over 30 years. Ginkgolic Acid Inhibits Coronavirus Strain 229E Infection of Human Epithelial Lung Cells https://mdpi-res.com/d_attachment/pharmaceuticals/pharmaceuticals-14-00980/article_deploy/pharmaceuticals-14-00980-v2.pdf