Merk makes most of the ivermectin sold in the U.S. That's as big as it gets. Here is their statement
about the use of ivermectin for the treatment of Covid.
https://www.merck.com/news/merck-statement-on-ivermectin-use-during-the-covid-19-pandemic/
- No scientific basis for a potential therapeutic effect against COVID-19 from pre-clinical studies;
- No meaningful evidence for clinical activity or clinical efficacy in patients with COVID-19 disease, and;
- A concerning lack of safety data in the majority of studies.