Allergy shots are one of the few treatments that can actually significantly reduce or even eliminate your allergy symptoms. This guide covers how allergy shots work, what to expect from the treatment process, and how to determine if this is the right choice for your situation.
What Are Allergy Shots?
Allergy shots are a type of treatment called immunotherapy. Unlike antihistamines or nasal sprays that temporarily relieve symptoms, allergy immunotherapy works by gradually training your immune system to tolerate the substances that trigger your reactions. Immunotherapy with allergy shots has been safely used for over a century.
Allergy Shot Alternatives
For patients who can’t or prefer not to use injections, sublingual immunotherapy (SLIT) is a suitable alternative. SLIT delivers allergens through drops or tablets placed under the tongue instead of through injections. Insurance coverage, effectiveness and range of allergies that can be treated vary between the two. Make sure to explore your options thoroughly before you start treatment. Your doctor can help you determine which form of immunotherapy makes the most sense based on your specific allergies, lifestyle, and medical history.
What's in an Allergy Shot?
Each injection contains a small, purified amount of the allergens that cause your symptoms. Your doctor creates a custom serum based on your specific allergy test results. Depending on what you react to, the serum might include extracts from tree pollen, grass, ragweed, dust mites, mold, pet dander, or insect venom.
The concentration starts very low and increases gradually with each injection. This slow progression gives your immune system time to adjust without triggering a severe reaction.
Types of Allergy Injections
The type of allergy shot you receive depends entirely on what you're allergic to. After comprehensive testing, your doctor identifies your specific triggers and formulates a serum tailored to your needs.
Common categories include:
- Pollen immunotherapy: Targets seasonal triggers like tree, grass, and weed pollens
- Perennial allergen immunotherapy: Addresses year-round allergens including dust mites, mold spores, and pet dander
- Venom immunotherapy: Protects against potentially life-threatening reactions to stings from bees, wasps, hornets, and fire ants
How Do Allergy Shots Work?
When you're allergic to something, your immune system treats a harmless substance (like cat dander or grass pollen) as a threat. In response, your body produces antibodies called IgE, which trigger the release of histamine. Histamine is what causes the sneezing, itching, congestion, and other symptoms you experience.
Allergy shots interrupt this cycle by changing how your immune system responds.
Allergy Desensitization
Through repeated exposure to tiny amounts of your allergens, your immune system gradually shifts its response. Instead of producing the IgE antibodies that trigger reactions, your body starts making "blocking antibodies" that intercept allergens before they can cause trouble. Over time, your IgE production decreases as well.
The result? Your allergic reactions become milder, less frequent, or in some cases, disappear altogether.
Allergy Shot Schedule
Immunotherapy follows a two-phase schedule:
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Build-up phase: This initial phase lasts 6-12 months, during which you receive 1-2 shots per week. The allergen dose is increased gradually. Once you reach your target dose, you transition to monthly maintenance injections.
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Maintenance phase: This phase lasts 3-5 years, during which you receive monthly shots. To obtain lasting results, patients must adhere to the schedule during the entire treatment.
How Long Does It Take for Allergy Shots to Work?
Patience is part of the process. Most patients begin noticing improvement within the first year, often during the build-up phase. However, the full benefits typically develop over two to three years of consistent treatment.
Some people respond within a few months, while others take longer. Your doctor will monitor your progress and adjust your plan as needed. Once you complete the full course, the benefits often persist for years. For some patients, the results become permanent.
There are times where health changes impact needing a longer timeline or a return to injections later on. For example, if people are having trouble with injections like an abnormal reaction, a doctor may need to go even slower with the timeframe and dosages. If you’re on immune suppression for another illness like Lupus, that can affect the way injections work too. These circumstances should be discussed with your doctor and handled on a case-by-case basis.
Are Allergy Shots Safe?
Allergy shots have been used safely for over a hundred years. However, because you're being injected with substances you're allergic to, reactions can occur.
Most reactions are mild and localized:
- Redness or swelling at the injection site
- Itching around the area
- Minor discomfort that fades within a few hours
Systemic reactions (symptoms affecting your whole body) are less common but possible. Hives, nasal congestion, or in very rare cases, anaphylaxis can occur. This is why allergy shots are typically given in a medical setting, where you'll wait 30 minutes after each injection so staff can monitor you.
Tip: Avoid vigorous exercise for a few hours after your shot, as physical activity can increase the chance of a reaction.
How Effective Are Allergy Shots?
For the right candidates, allergy shots are highly effective. Research shows that approximately 80% of patients with allergic rhinitis experience significant improvement. For those with allergic asthma triggered by environmental allergens, immunotherapy can reduce symptoms and decrease reliance on asthma medications.
For people who fall into the other 20%, either allergy shots don’t work at all for their system, or their effectiveness did not last long after the round of shots were completed. Doctors don’t know exactly why this happens. If shots worked during the treatment, some patients may choose to resume injections for different periods of time because they help to manage symptoms.
Allergy Shots For Children
Children whose symptoms are not well controlled with over-the-counter or prescription medications, or who experience recurring complications from allergic rhinitis, may be good candidates for allergy shots. If you are a parent concerned about allergies, ask your doctor for guidance.
Where to Get Allergy Shots
Where you receive your allergy shots matters for both safety and effectiveness. Understanding your options helps you make an informed choice.
Allergy Shots at a Clinic
Most patients receive allergy shots at an allergy clinic or doctor’s office. This setting provides immediate access to medical professionals who can respond quickly if a reaction occurs. A typical visit takes about 30 minutes: a few minutes for the injection itself, followed by a required observation period.
Clinic-based treatment also ensures proper storage of your allergy serum, which requires refrigeration to stay effective.
Allergy Shots at Home
Some practices allow home injections, which can be more practical for many patients. You will need to meet with the doctor first to go over your medical history and get approved for at-home treatment. Once you are cleared, you will receive training on how to administer your own shot safely and effectively, and how to properly store your serum.
Allergy Shots in Louisville, KY and Kentuckiana
For patients in Louisville, Central Kentucky, and Southern Indiana, Advanced ENT & Allergy offers comprehensive allergy testing and immunotherapy services at multiple convenient locations.
Our dedicated Allergy Center provides the specialized care and monitoring that immunotherapy requires. We also offer a cluster build-up where we can get to maintenance in 8 visits. Your doctor can discuss if this is a good option for you.
At-home allergy shots are also available for qualifying patients, with a follow-up at the clinic every 3 months to monitor progress. Schedule an appointment to learn more about your options!
Frequently Asked Questions About Allergy Shots
Allergy Injection Cost and Insurance Coverage
Are allergy shots covered by insurance?
Most health insurance plans cover allergy shots because immunotherapy is recognized as medically necessary treatment for allergic conditions. Coverage typically includes both serum preparation and injection administration fees. Contact your insurance provider to verify your specific benefits and any copay requirements.
How much are allergy shots without insurance?
Allergy shot costs are made up of two parts: the vial mix and the injection visits. The allergen vials are typically remixed every two months. The cost is $200 for one vial mix or $400 for two vial mixes. Over the course of a year, that usually means about six mixes, totaling approximately $1,200 per year for one vial or $2,400 per year for two vials. In addition to the vial cost, there is an injection administration fee each time you come in for shots. The fee is $14 for one injection or $17 for two injections per visit. During the build-up phase, patients typically come in once or twice per week, depending on their treatment plan.
For example, if someone requires two vials and comes in once per week for a year during the build-up phase, the estimated total cost would be around $3,300 for the year. Actual costs can vary based on how many vials are needed and how frequently injections are given.
Please note that these figures are approximate, reflect pricing as of March 2026, and might change later on.
Does Medicaid cover allergy shots?
Medicaid coverage for allergy shots varies by state. In Kentucky and Indiana, Medicaid typically covers immunotherapy when deemed medically necessary. Your doctor's office can help verify coverage and obtain any required prior authorizations.
Side Effects and Patient Concerns
Can allergy shots cause weight gain?
There is no scientific evidence linking allergy shots to weight gain. The injections contain only allergen extracts in very small quantities. If you notice weight changes during treatment, other factors are likely responsible.
Can allergy shots make you tired?
Some patients report mild fatigue after receiving allergy shots, particularly during the build-up phase. This is usually temporary and resolves within a day. If persistent fatigue occurs, mention it to your doctor.
Can allergy shots make you sick?
Allergy shots don't cause illness in the traditional sense, but they can trigger allergy symptoms as your body responds to the injected allergens. Mild sneezing, nasal congestion, or itchy eyes occasionally occur after injections and typically resolve quickly.
When to worry about an allergy shot reaction?
Seek immediate medical attention if you experience difficulty breathing, throat tightness, dizziness, rapid heartbeat, or widespread hives after an allergy shot. These symptoms could indicate anaphylaxis, a serious reaction requiring emergency treatment. If you are doing allergy shots at home, your doctor will prescribe you an epinephrine auto injector (“epiPen” or similar brands) just in case anaphylaxis occurs. Go to the hospital right after using your epinephrine auto injector.
Are there long-term side effects of allergy shots?
Long-term side effects from allergy shots are extremely rare. The treatment has been used safely for over 100 years. Most patients experience only the intended effect: reduced allergic sensitivity that persists for years after completing treatment.
Related Health Questions
Do allergy shots help asthma?
Yes, allergy shots can significantly benefit patients whose asthma is triggered by environmental allergens. Immunotherapy reduces asthma symptoms, decreases medication requirements. However, patients with severe or uncontrolled asthma may not be good candidates for this treatment.
Can you get allergy shots while pregnant?
If you're already receiving allergy shots and become pregnant, you can typically continue maintenance injections at your current dose. However, starting immunotherapy or increasing doses during pregnancy is generally not recommended due to the small risk of anaphylaxis. Discuss your specific situation with both your allergy doctor and obstetrician.
Shot and Serum Questions
How many days can you go between allergy shots?
During the build-up phase, shots are typically given one to two times per week, with at least one day between injections. During maintenance, monthly intervals are standard, though some flexibility exists. Going too long between shots (especially during build-up) may require restarting at a lower dose for safety.
How long can allergy serum be left unrefrigerated?
Allergy serum requires refrigeration to maintain effectiveness. If left unrefrigerated for more than a few hours, the serum may lose potency or become unsafe to use. Always transport your serum in a cooler with ice packs if traveling between appointments.
How many days do I need to wait between allergy shots and flu shots?
There's no required waiting period between allergy shots and flu vaccines. However, some doctors prefer spacing them by a few days to better identify the source of any reactions that might occur. Ask your provider about their specific recommendations.
