What Are Allergy Shots and Do They Actually Work?

If you have been dealing with allergies for years, you may feel like you are constantly trying to control the symptoms.

Antihistamines, nasal sprays and avoiding your triggers can help. But for some people, symptoms keep coming back despite doing all the right things.

That is where allergy immunotherapy, commonly called allergy shots, may be an option.

What Are Allergy Shots?

Allergy shots are a treatment designed to change how your immune system responds to specific allergens.

Instead of simply treating symptoms after they appear, allergy shots gradually expose your immune system to carefully controlled amounts of the substances you are allergic to.

Over time, this can make your immune system less sensitive to those allergens.

What Allergies Can Be Treated?

Allergy shots may be used for certain environmental allergies, including:

• Tree, grass and weed pollen
• Dust mites
• Pet allergens
• Mould
• Insect venom

They are not used to treat food allergies in the same way.

Your allergist will determine whether immunotherapy is appropriate based on your symptoms, medical history and allergy testing.

How Do Allergy Shots Work?

Treatment usually starts with very small amounts of the allergen.

The dose is gradually increased during what is called the build-up phase.

Once you reach an appropriate dose, you move into the maintenance phase. The injections are then spaced farther apart.

The exact schedule can vary depending on the patient and the treatment plan.

Do Allergy Shots Work Right Away?

No.

Allergy immunotherapy is a long-term treatment.

Some people begin noticing improvement during the first year, but it can take time for the full benefit to develop.

A typical course of maintenance treatment may continue for several years.

This is very different from taking an antihistamine when your nose starts running. The goal of immunotherapy is to gradually change your allergic response rather than simply provide temporary symptom relief.

Do Allergy Shots Actually Work?

For the right patient, they can be very effective.

Allergen immunotherapy can reduce allergy symptoms and may reduce the amount of allergy medication some people need.

Some patients continue to experience benefits even after completing treatment.

Results vary, which is why allergy shots are prescribed based on your individual symptoms and confirmed allergy triggers.

Who Might Consider Allergy Shots?

Immunotherapy may be worth discussing if:

• Your allergies significantly affect your daily life
• Symptoms continue despite appropriate medication
• You need allergy medication frequently
• You have unavoidable exposure to something you are allergic to
• You experience significant seasonal allergies every year
• You want to explore a longer-term treatment approach

It is not automatically the right treatment for everyone.

Are Allergy Shots Safe?

Allergy shots are generally well tolerated when given appropriately, but they contain substances that you are allergic to, so reactions can occur.

The most common reaction is redness, itching or swelling around the injection site.

More serious allergic reactions are uncommon but possible.

For this reason, allergy injections are given in a medical setting where trained staff can recognize and treat an allergic reaction if one occurs.

Patients are usually asked to remain at the clinic for a period of observation after an injection.

What If I Have Asthma?

Asthma is important to discuss before starting and during allergy immunotherapy.

Poorly controlled asthma can increase the risk associated with allergy injections.

Tell your allergy team if your asthma symptoms have recently become worse or if you are experiencing coughing, wheezing, chest tightness or shortness of breath before receiving an injection.

Your allergist can determine whether it is safe to proceed.

Is There an Option Without Injections?

For certain allergies, another form of immunotherapy may be available that uses tablets placed under the tongue.

This is called sublingual immunotherapy.

It is not interchangeable with allergy shots and it is not available for every allergen.

Your allergist can explain which immunotherapy options are appropriate for your specific allergies.

Do I Still Need to Avoid My Allergens?

Usually, yes.

Allergy immunotherapy does not mean you should suddenly expose yourself to large amounts of something you are allergic to.

Reducing unnecessary exposure and using medications when recommended may still be part of your allergy plan, especially while immunotherapy is taking effect.

How Do I Know If Allergy Shots Are Right for Me?

The first step is identifying what you are actually allergic to.

Your symptoms and allergy test results need to make sense together. A positive allergy test by itself does not automatically mean you need allergy shots.

An allergist looks at your symptoms, how much the allergies affect your life, which treatments you have already tried and whether immunotherapy is likely to help.

The Bottom Line

Allergy shots are different from medications that temporarily control sneezing, congestion and itchy eyes.

They work gradually by changing how your immune system responds to specific allergens.

Treatment takes commitment and usually continues for several years, but for the right patient it can provide meaningful and potentially long-lasting improvement.

If your allergies continue to interfere with your sleep, work, school or everyday life despite treatment, Dandelion Allergy Centre can assess your triggers and determine whether allergy immunotherapy may be an option for you.

This article is for general information and does not replace medical advice from your healthcare provider.