CHICAGO (NewsNation Now) — “You are not a horse. You are not a cow. Seriously, y’all. Stop it.”

That’s the Food and Drug Administration’s message in a recent tweet as it tries to combat a rise in people using an unauthorized animal medication to treat COVID-19.

Ivermectin is used to treat and prevent parasites in animals. The large-concentration tablets are dangerous for humans and can lead to severe side effects including seizures, allergic reactions and even death.

In addition to not being authorized for treating COVID-19, ivermectin is not an anti-viral medication and there is no evidence it works against coronavirus.

The Mississippi Poison Control Center said at least 70% of recent ivermectin-related calls are tied to people taking livestock or animal formulations they bought at a livestock supply stores or through online markets.

Eighty-five percent of callers had mild symptoms — these include rash, nausea, vomiting, and abdominal pain — but one person needed evaluation because of how much they’d taken.

Ivermectin for humans, in specific doses, is approved to treat conditions like head lice and rosacea. The animal kind, on the other hand, is not approved for use by any humans.

Despite these warnings, false claims of the drug’s effectiveness have proliferated on Facebook and in more vaccine-hesitant circles.

During a Senate hearing last year, ivermectin was championed alongside hydroxychloroquine as medications effective against COVID-19.

Since then neither medication has been formally found to be effective in combatting COVID-19.

The FDA said they are working with the Federal Trade Commission to investigate sellers of fraudulent COVID-19 medication products. Retailers are being asked to remove any listing that contains a promise to treat COVID-19 without approval by the FDA.

NewsNation affiliate KXAN contributed to this report.