Are allergy shots harmful?

Allergy shots are usually safe. But because allergy shots contain small amounts of the allergen you're allergic to, you might have an allergic reaction to the shot itself. One kind of allergic reaction is swelling at the place where the shot is given.

People can also have severe, shock-like reactions to an allergy shot. This type of reaction is called anaphylaxis and is very serious. But this problem rarely happens. If you get your shots on schedule (every week or every month), you're less likely to have this kind of reaction.

In case you have a bad reaction, your doctor will have you stay at the office for about 20 minutes every time you get your shot. That way, if you have a reaction to the shot, your doctor can give you something right away to stop it.