Ivermectin has antiviral effects against several distinct positive-sense single-strand RNA viruses, including SARS-CoV-2.[79] On 10 April 2020, the FDA issued guidance to not use veterinary-grade ivermectin as treatment for COVID-19 in humans.[80][81]
Ivermectin inhibits replication of SARS-CoV-2 in monkey kidney cell culture with an IC50 of 2.2 - 2.8 µM, making it a possible candidate for COVID-19 drug repurposing research.[82][83] The doses used in cell culture would require 104 larger doses in humans based on this data, which does not look promising as an effective treatment for COVID-19.[84][85] Such high doses of ivermectin are not covered by the current human-use approvals of the drug and could be dangerous, as the likely antiviral mechanism of action is the suppression of a host cellular process,[85] specifically the inhibition of nuclear transport by importin α/β1.[86]
A preprint published in April 2020 claimed benefits of ivermectin in the treatment of COVID-19, but it was a retrospective study based on questionable hospital data from Surgisphere and was withdrawn at the end of May. The preprint led to several government agencies in Latin America recommending ivermectin as a COVID-19 treatment; these recommendations were later denounced by the regional WHO office.[87] On October 12, 2020 Peru withdrew its authorization to use ivermectin and hydroxychloroquine as COVID-19.[88]
In November 2020 a meta-analysis found only weak evidence of benefit.