That's actually more a dose problem than anything else. The horse paste comes in a syringe with markings for 250 to 1250 pounds your horse weighs. The stuff is 1.87% ivermectin and you are supposed to take 200-300 ug/kg. Figuring how much to take involves some math most people have not done since high school (if ever). And according to the FLCCC (the biggest American advocates) the dose is quite important. That's one of their biggest complaints: That some trials have used far too little given only once, or far too much causing toxic effects.

We're flying electric helicopters on Mars yet you can't turn on your clothes dryer in Texas. That's because scientists are in charge of Mars, and Republicans are in charge of Texas.