Do Allergy Shots Really Work?

What to Consider Before Starting Immunotherapy for Your Allergies

Patient receiving allergy, vacation vaccination.
Getty Images/ Peter Dazeley

Millions of Americans suffer from various types of allergies. Sometimes symptoms are so severe that they become debilitating or can increase a person's risk of dying from an anaphylactic reaction. If other treatments have been unsuccessful, you may be considering allergy shots or immunotherapy. But do allergy shots really work? Are they worth the risk? Here's what you need to know before choosing immunotherapy.

Testing for Allergens

Before starting treatment with allergy shots, your doctor will first run tests to find out the exact substance (or substances) that you are allergic to. If your allergy is a substance in the environment, such as certain types of pollen, you may be eligible for allergy shots. Food allergies, however, are not treated with allergy shots.

Shots to Desensitize You to Your Allergy Triggers

The substances you are allergic to are called allergens or triggers. Once it's determined what you are allergic to, immunotherapy involves a series of repeated injections of that allergen. The theory is that by exposing your body to the allergen, it will become desensitized to the substance (versus automatically launching the immune response -- the process that causes symptoms).

So, do allergy shots work? The short answer is yes, but not for everyone. Allergy shots are not a treatment option that should be taken lightly.

There are many considerations, including a substantial time commitment, the risk of an allergic reaction to the shots, and the possibility that only some of your symptoms may be cured, or none at all.

Allergy Shots Take Time: Build Up and Maintenance

Completing immunotherapy may mean you'll have to go to the doctor's office two or more times per week for several months.

The treatment is broken up into two phases called the build-up phase and the maintenance phase. During the build-up phase, you are given increasing amounts of the allergen 1-2 or more times per week. This phase lasts 3-6 months.

The second phase is called the maintenance phase. During the build-up phase, your doctor will determine the best dose of medication (allergen) for you. This is your maintenance dose, which is what you'll receive for the remaining allergy shots and what your doctor feels you respond to best. The good news is that during the maintenance phase, you will only need to get shots every 2-4 weeks. The maintenance phase lasts about three years.

Allergy Shots Have Risks

There is always the chance that you could have an allergic reaction to an allergy shot, which could lead to anaphylaxis and even death. It may seem a bit like tempting fate to give someone a substance you know they react to, but you only receive very small amounts staggered over a long period.

Serious reactions are rare, but you should be sure to only undergo immunotherapy when administered by a qualified allergist/immunologist.

These doctors have equipment in their offices for treating allergic reactions. If you are going to have a reaction to the shot, it will happen within about 30 minutes, so you should stay at your doctor's office for at least a half hour after receiving the shot.

Allergy Shots Don't Always Work

The results of immunotherapy vary widely from one person to another, with some people completely cured and some individuals showing little to no benefit. Almost all patients experience, at the least, a reduction in symptoms. Even if your allergies go away completely, there is always the possibility that they will return, and you will require another round of allergy shots.

Immunotherapy can be a blessing for many people who suffer from allergies, but as you can see, it is not a treatment to be taken lightly. You may wish to ask yourself some of the following questions before making a decision.

  • Do I have the time, and am I willing to spend that time getting allergy shots?
  • Can I afford allergy shots?
  • How many months of the year do my allergies affect me?
  • How serious are my symptoms?
  • Are my allergies decreasing my quality of life?
  • Have I tried other treatments?

If you have not tried other treatments, such as avoiding your triggers, and taking antihistamines (such as loratadine or Allegra) or other medications to treat allergy symptoms (such as pseudoephedrine or Nasonex), I recommend trying these options before having immunotherapy. However, only you and your doctor can decide if allergy shots are right for you.


American Academy of Allergy, Asthma and Immunology. Allergy Shots: Tips to Remember. Accessed April 24, 2011 from

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