Should You Get Allergy Shots?

Medically Reviewed by Carol DerSarkissian, MD on January 24, 2023
6 min read

You probably take something to ease your seasonal allergy symptoms. Maybe you’re using more and more medicine over time, or it’s not working that well. You may be thinking about switching to immunotherapy to see if that helps more.

Immunotherapy for allergies exposes you to a tiny amount of your allergy trigger so that over time, your body learns to handle it better. This can make a big difference in your allergy symptoms. 

“A lot of patients now are looking for more natural treatment options and minimizing the amount of medications they’re needing,” says Kara Wada, MD, an assistant professor of allergy and immunology at the Ohio State University Wexner Medical Center.

If you’ve got asthma, it must be under good control before you start this type of treatment because exposure to your allergy trigger has the potential to cause a flare-up.

Allergy shots are one form of immunotherapy for allergies. You get the shots in a doctor’s office. They can make a big difference and may even get rid of your symptoms. But it may take years for them to take full effect.

Sublingual immunotherapy is another form. It uses tablets. (“Sublingual” means that the medicine goes under your tongue.) Sublingual treatments haven’t been studied as much as allergy shots. They haven’t been shown to work as well as allergy shots. But if you’re up for the commitment of taking the medicine day in, day out, as prescribed, it might be an option to explore for the specific allergies it targets.

If you’re interested in allergy shots or sublingual immunotherapy, you first need to visit your allergist and get tested to pinpoint exactly what you’re allergic to, if you haven’t done this already.

With allergy shots, your allergist creates a shot formulation that’s based on your test results. You’ll need to get a shot from your allergist once or twice a week for 3-6 months. You’ll get the shot in your upper arm. It'll contain a tiny amount of the thing you’re allergic to -- pollen, pet dander, mold, dust mites, or bee venom, for example.

Each week, your doctor will raise the amount of allergens in the shot until you reach a maintenance dose. Your doctor might recommend that you take an antihistamine before you get each treatment.

Once you reach the maintenance dose, you can usually cut back on your visits (and shots) to every 2-4 weeks, a schedule you keep for 3-5 years or until your symptoms improve. “There seems to be some point within that window when the immune response changes,” Wada says.

You’ll need to wait in your allergist’s office for about half an hour after each allergy shot to make sure you don’t have a serious reaction.

With sublingual immunotherapy, your treatment will probably start 12-16 weeks before pollen season begins and last through pollen season. You take the first dose in the allergist’s office and the rest at home.

The most obvious drawback for allergy shots is the time commitment. You must stick to a weekly schedule of allergist visits for months, and it could be years of monthly follow-ups before you see significant improvement.

That said, symptoms generally start to improve within the first year of treatment and often continue to get better during the second year. By the third to fifth year, most people are free of allergy symptoms and may be able to stop getting shots.

If your symptoms don’t improve after a year of shots, talk with your doctor about other treatment options.

Aside from time, there’s the potential for a reaction to the treatment, since it has small amounts of the things you’re allergic to. For instance, you may have redness or swelling around the injection site if you get a shot, or you may have other symptoms.

“Sometimes, patients report an increase in nose or eye symptoms, such as stuffy nose, runny nose, or itchy eyes,” says allergy immunologist Kathleen Dass, MD, of the Michigan Allergy, Asthma & Immunology Center. 

It’s rare, but it’s also possible to have anaphylaxis, which is a severe allergic reaction involving hives, swelling, trouble breathing, dizziness, and loss of consciousness. That’s why you need to get the treatment in your allergist’s office and wait there for a while after each shot, Dass says.

Sublingual immunotherapy treatments often cause mouth and throat irritation, Wada says. But they’re less likely to lead to anaphylaxis, research shows. 

Allergy shots can be expensive, but they’re generally covered by insurance. Check your plan. If you have a high-deductible health plan, you may have to pay out of pocket until you hit your deductible each year.

If you’re thinking about sublingual treatment, you can get it only for allergies to ragweed, certain grasses, and dust mites. So if you’re having reactions to a different type of allergen, it’s not an option.

If you stick with allergy shots long enough, there’s a good chance you’ll see improvement or even an end to your allergy symptoms. About 85% of people with hay fever who get this type of treatment say their allergy symptoms get better.

“That’s one of the things I find pretty neat as an allergist,” Wada says. “Typically, a lot of the treatments we have are geared toward treating the symptoms. This is one of the few things we have toward the root of the problem.”

You may want to avoid exercise or doing anything strenuous for 2 hours before and after your appointment. Exercise boosts blood flow to the tissues and may cause the allergens to spread throughout your body faster. It’s not likely to cause a serious problem, but it’s best to be safe.

Tell your doctor about any other medicines or herbs and supplements you take. Some medications interfere with the treatment or raise the risk of side effects. You may need to stop allergy shots if you take these medications.

If you’re pregnant or planning to get pregnant, ask your doctor whether you should continue to get allergy shots.

Usually, you’ll stay at the doctor’s office for about 30 minutes after you get an allergy shot. That's to make sure you don't get side effects like itchy eyes, shortness of breath, a runny nose, or a tight throat. If you get these symptoms after you leave, go back to your doctor's office or to the nearest emergency room.

Redness, swelling, or irritation right around the site of the injection is normal. These symptoms should go away in 4 to 8 hours.

Get on the phone and go to the nearest emergency room if you have shortness of breath, a tight throat, or any other symptoms that worry you after getting your shot.

They may be more risky for people with heart or lung disease, or who take certain medications. Tell your allergist about your health and any medicines you take, so you can decide if allergy shots are a good option for you.