The Food and Drug Administration warned against using ivermectin — a drug often used in the U.S. to treat or prevent parasites in animals — to treat or prevent COVID-19 in humans.
“You are not a horse. You are not a cow. Seriously, y’all. Stop it,” the FDA tweeted Saturday morning, linking to a piece explaining the dangers of self-medicating with ivermectin doses intended for horses.
The FDA also shared a set of frequently asked questions about the use of ivermectin, saying the drug is not approved for use against COVID-19. It also emphasized that there is no emergency use authorization for the drug as a treatment for the coronavirus.
In March, the World Health Organization advised ivermectin should only be used in clinical trials, saying evidence on its use to treat COVID-19 is “inconclusive.”
You are not a horse. You are not a cow. Seriously, y'all. Stop it. https://t.co/TWb75xYEY4
— U.S. FDA (@US_FDA) August 21, 2021
The FDA’s message comes a day after Mississippi officials, prompted by an increase in calls to the state’s poison control center, warned residents against using the drug, noting “animal doses are not safe for humans.” An alert sent to the state’s health care providers said “at least 70% of the recent calls” to poison control had been related to the ingestion of ivermectin purchased at livestock supply centers.
Ivermectin tablets have been approved by the FDA to treat patients with some conditions caused by parasitic worms, and the medicine is used to treat or prevent parasites in some animals, like horses. Some initial research is being done on the effect of ivermectin on SARS-CoV-2, the virus that causes COVID-19, but the FDA has been clear that “additional testing is needed to determine whether ivermectin might be appropriate to prevent or treat coronavirus or COVID-19.”
The FDA has granted emergency use authorizations for three COVID-19 vaccines — the Johnson & Johnson, Moderna and Pfizer-BioNTech shots — which are widely available in the United States. Full FDA approval of the Pfizer vaccine is expected Monday, according to The New York Times.
This article originally appeared on HuffPost and has been updated.