A mixture of mostly avermectin H2B1a (RN 71827-03-7) with some avermectin H2B1b (RN 70209-81-3), which are macrolides from STREPTOMYCES avermitilis. It binds glutamate-gated chloride channel to cause increased permeability and hyperpolarization of nerve and muscle cells. It also interacts with other CHLORIDE CHANNELS. It is a broad spectrum antiparasitic that is active against microfilariae of ONCHOCERCA VOLVULUS but not the adult form. In vitro data suggest evidence of activity against SARS-CoV-2, but to date available data are insufficient to recommend either for or against the use of ivermectin for the treatment of COVID-19. FDA issued a warning concerning possi-ble inappropriate use of ivermectin products intended for animals as an attempt to self-medicate for the treat-ment of COVID-19.