From the manufacturer: Horse Health™ (ivermectin paste) 1.87% is FDA-Approved for equine use only, and only pursuant to, and in accordance with, its label. It is only effective for the approved indications on the label. This product has not been tested in humans and is not approved for use with humans. Any and all off-label use is unsafe, and is strictly prohibited.
Important information from the FDA regarding Ivermectin and Covid-19
Effective deworming depends on the right amount of dewormer getting into your horse. Make sure you give your horse the right amount of paste for his size, and that he swallows all the paste you give him. Adjust the syringe to your horse’s weight by locking the ring at the correct weight marking on the plunger. Be sure to read the product information in its entirety before deworming your horse.