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Allergen immunotherapy consists of a series of treatments aimed at providing long-term relief from severe allergies.

It’s also known as:

  • allergy immunotherapy
  • subcutaneous immunotherapy
  • allergy shots

You might consider allergy shots if you have severe allergy symptoms that interfere with your daily life, even after you’ve made changes to your immediate environment.

These shots may be used to treat allergies caused by:

When taken in the recommended sequence, allergy shots can provide significant symptom relief. At the same time, this treatment option requires a long-term commitment to work effectively.

This treatment method requires frequent injections at the doctor’s office. You need to be able to commit time to it.

Allergy shots may be used by people who have:

Allergy shots tend to work best for people who are sensitive to insect venoms and inhaled allergens.

You may also be a good candidate if you experience severe allergy symptoms year-round and you don’t want to take medications over a long period of time.

Who shouldn’t take allergy shots?

Allergy shots are only used in people who are at least 5 years old. That’s because children younger than 5 years old may not be able to fully communicate about potential side effects and discomfort that would warrant stopping treatment.

Allergy shots also aren’t recommended if you:

Allergy shots work by decreasing symptoms from particular allergens.

Each injection contains small amounts of the allergen so that your body builds up immunity to it over time. The process works much like taking a vaccine, where your body creates new antibodies to combat the invasive substances.

Allergy shots also improve the way other immune system cells and substances function in response to allergens. Eventually, successful immunotherapy helps the body fight off allergens and reduce adverse symptoms.

Allergy shots aim to decrease overall allergy symptoms over time. If you have allergic asthma, reduced asthma symptoms are also possible.

Before you start allergy shots, you’ll need a full evaluation. The doctor needs to test your allergies to know exactly which substances to use in the shots.

For example, if you have allergies during pollen season, they’ll test for which types of pollen cause your symptoms. Ragweed, grasses, and various tree pollens are common culprits.

Allergy testing usually consists of skin pricking. During a skin prick test, your doctor will prick the skin on your back or forearm with several types of allergens to determine which ones cause reactions.

A type of specialist known as an allergist or an immunologist will conduct all testing and treatment with allergy shots.

Once your doctor has identified your allergens, you’ll start receiving allergy shots. The process is broken down into two phases:

  • buildup
  • maintenance


The buildup phase requires the largest time commitment. You receive injections up to twice per week to help your body get used to the allergens.

You’ll need to stay at your doctor’s office for 30 minutes after each injection so they can monitor any side effects and reactions.

The buildup phase typically lasts 3 to 6 months.


The maintenance phase consists of shots administered once or twice per month.

You enter the maintenance phase once your doctor determines that your body has grown accustomed to the injections. They base this decision on your reaction to the shots.

The maintenance phase typically lasts between 3 and 5 years. It’s important that you don’t skip any of your injections, if possible. Doing so can disrupt your treatment course.

During this phase, you’ll also need to stay at your doctor’s office for 30 minutes post-injection so that they can monitor your reaction.

Allergy shots can provide long-term relief well after the injections have stopped.

Some people who have received allergy shots may no longer need medication for their allergies.

However, it can take up to 1 year of maintenance shots before you see results. Some people may notice benefits early on in the maintenance phase, though.

In some cases, allergy shots don’t work. This may be due to a variety of reasons, including:

  • stopping treatment due to reactions
  • continued exposure to allergens at extremely high levels
  • not enough allergen in the actual shots
  • missed allergens during your initial evaluation

Common side effects include reactions that look like hives or mosquito bites at the site of the injection. The area can also swell to a larger bump and increase in redness.

This type of reaction is normal. It can happen immediately or several hours after the injection.

It can last for several hours before going away without any treatment. You can help reduce swelling by applying ice to the injection site.

Some people experience mild allergy symptoms — including nasal congestion, sneezing, and itchy skinafter their shots. This is a reaction to the allergens being injected. Taking an antihistamine can help ease these symptoms.

Rare side effects

In rare cases, allergy shots may cause a severe reaction, including:

If you go into anaphylactic shock, you may experience dizziness and breathing difficulties.

This reaction can develop within 30 minutes of receiving an allergy shot. This is why your doctor will likely ask you to stay at the office after the injection so that they can monitor you.

When you’re feeling sick

If you’re sick, let your doctor know. You may need to skip an injection until you’ve recovered.

Taking an allergy shot while you have a respiratory illness, for example, could increase your risk for side effects.

Health insurance typically covers allergy shots. You may have to pay a copay for each visit. Copays are usually nominal fees.

If you don’t have health insurance, have a high deductible, or if allergy shots aren’t covered under your plan, you may end up spending thousands of dollars a year.

One large 2019 study looked at the costs of allergy shots for people with commercial insurance or Medicare Advantage with Part D. Researchers examined data gathered between 2013 and 2015.

  • The cost of allergy shots for 131,493 people totaled $253,301,575. This averages out to around $1,926 per person.
  • People with allergies covered about 19 percent of the total costs, while insurers covered about 81 percent.
  • On average, treatment lasted 463.1 days (or around 15 months).

Before beginning any treatment, talk with your doctor about payment options and costs.

Keep in mind that allergy shots are a long-term commitment. They require many injections, so you’ll want to plan accordingly if you’re paying out of pocket.

Also consider that, over time, allergy shots could save you money on sick visits and over-the-counter (OTC) allergy medications.

Speak with your doctor about the requirements for allergy shots and whether shots are a good option for you.

Many people respond well to allergy shots, and they can provide a source of freedom from severe allergies. It may take a while for you to see results, though.

If you don’t see any improvements after 1 year, you may need to talk to your allergist about other options for allergy control.

If you have food allergies, speak with your doctor about ways you can avoid the foods you’re allergic to. Allergy shots aren’t effective against food allergies.