It’s free. Here is a study from the NIH website published on June 9, 2021. From the study “Moreover, we have compared NhPV with another compound, Suramin, for their anti-SARS-CoV-2 activities and the mode of their actions, and found that both NhPV and Suramin are able to directly interrupt SCoV-2–SP binding to its receptor ACE2 and block the viral entry step.”
Pine needles have vitamins A and C and suramin.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8189562/