How do people make anti venom from snake venom?

Question

Do they add something to it or what?

Answer 1

they will add a small amount to your body so when it happens again your body will know what it is and be able to fight it off when you are bitten. same way with the flu shot they are injecting a small amount of that way if you are exposed to it and it gets in your system it can fight it off.

Answer 2

They inject tiny amounts into horses and they build a resistance to it. Then they use the horse blood as a anti venom, they use horses because they are  large animals and venom will not affect them as much

then drawn from the horse and immunoglobulins

Answer 3

Billy B is right, it's the blood plasma from horses that have been exposed to that specific venom (or venoms...) BUT, sometimes humans have a bad reaction to horse blood when it's injected into their systems. Some antivenins are available now based in sheep blood (more widely accepted by our systems) and even egg albumin...

In some cases, if you are bitten by a venomous snake, you will be observed for a while and maybe no antivenin will be administered. About 75% of venomous snake bites in North America are "dry bites" where the snake injects no venom at all, and the victim's immune system will be able to handle any residual venom from the snake's fangs without help. (You can have a worse reaction to the horse blood than the venom itself in some cases.)