Allergy Shots: What to Expect, Timeline, Benefits, and Risks

Allergy Shots Can Change How Your Immune System Reacts

Allergy shots, also called allergy immunotherapy or subcutaneous immunotherapy (SCIT), are a long-term treatment that helps your immune system become less reactive to specific allergens. Unlike antihistamines or nasal sprays, which mainly control symptoms while you keep using them, allergy shots are designed to change the underlying allergic response over time.

The American Academy of Allergy, Asthma & Immunology (AAAAI) describes allergy shots as a long-term treatment that can decrease symptoms for many people with allergic rhinitis, allergic asthma, allergic conjunctivitis, and stinging insect allergy. The same AAAAI guidance notes that allergy shots may provide lasting relief even after treatment is stopped.

This guide explains what allergy shots are, what to expect at each appointment, how the allergy shots timeline usually works, the main benefits, the most important risks, and how to decide whether to talk with an allergist.

> Quick summary: Do allergy shots work and how long do they take? Allergy shots can work well for many people with pollen, dust mite, mold, pet dander, cockroach, allergic asthma, eye allergy, or stinging insect allergy. Treatment usually includes a buildup phase for about 3 to 6 months, followed by a maintenance phase every 2 to 4 weeks for about 3 to 5 years. Many people notice improvement during treatment, but meaningful relief can take several months and may take up to 12 months on the maintenance dose.

What Are Allergy Shots (Immunotherapy)?

Allergy shots are injections that contain tiny, controlled amounts of the allergens that trigger your symptoms. Over time, the dose is gradually increased until you reach a maintenance dose that your immune system can tolerate.

The goal is not to cause an allergic reaction. The goal is to teach your immune system to respond less aggressively when you encounter that allergen in real life.

How do allergy shots work?

Allergy shots work by repeated, medically supervised exposure to specific allergens. In simple terms, they act like a training program for your immune system.

Your allergist first identifies your triggers using your history and allergy testing. Then the allergy shot formula is customized to the allergens that are clinically relevant for you. Each injection contains a measured dose, and the dose is increased slowly enough to reduce risk while building tolerance.

A helpful way to think about allergy shots is this: they are not a quick symptom blocker; they are a disease-modifying treatment. Medications may reduce sneezing, itching, congestion, or wheezing for the day. Allergy immunotherapy aims to make your future reactions less intense.

What allergies can allergy shots treat?

Allergy shots are most often used for allergies caused by:

• Tree, grass, and weed pollen
• Dust mites
• Mold spores
• Pet dander
• Cockroach allergens
• Stinging insects, such as bees, wasps, hornets, and yellow jackets

They may be considered for allergic rhinitis, seasonal allergies, year-round indoor allergies, allergic conjunctivitis, allergic asthma, and stinging insect allergy.

What do allergy shots not treat?

Standard allergy shots are not used to treat food allergies. Food allergy care usually focuses on strict avoidance, emergency preparedness, and in select cases, specialist-supervised food immunotherapy. That is different from standard environmental allergy shots.

Allergy shots also are not a treatment for chronic hives that are not driven by a specific inhaled or insect allergen. If your symptoms are not clearly linked to an IgE-mediated allergy, an allergist can help clarify whether immunotherapy is appropriate.

The Allergy Shots Timeline: What to Expect

The allergy shots timeline usually has two main phases: the buildup phase and the maintenance phase. Your exact schedule may vary based on your allergens, reaction history, asthma control, clinic protocol, and whether your allergist uses a conventional or accelerated schedule.

Phase

Typical frequency

Typical duration

Main goal

Buildup phase	About 1 to 2 times per week, sometimes more depending on protocol	About 3 to 6 months	Gradually increase allergen dose and build tolerance
Maintenance phase	About every 2 to 4 weeks	Usually 3 to 5 years	Maintain desensitization and support long-term symptom relief

Phase 1: The buildup phase

The buildup phase is the beginning of allergy immunotherapy. During this phase, you receive injections containing increasing amounts of your allergens. Many conventional schedules involve shots once or twice per week, and some practices use schedules that may involve more frequent visits.

This phase usually lasts about 3 to 6 months. The goal is to reach a dose that is high enough to be effective but still safe for you.

During buildup, your allergist may adjust your dose if you have a reaction, miss visits, develop an asthma flare, become ill, start a new medication, or have a major change in health status. These adjustments are normal and are meant to reduce risk.

Phase 2: The maintenance phase

The maintenance phase begins when you reach your target dose. At this point, your visits become less frequent, often about every 2 to 4 weeks.

Maintenance treatment is usually continued for 3 to 5 years. Some people have lasting relief after stopping. Others relapse and may need a longer course or a different allergy plan. The decision to continue, adjust, or stop allergy shots should be made with your allergist.

When will you see results from allergy shots?

Some people notice fewer symptoms during the buildup phase. Others do not feel a major difference until they have been on maintenance dosing for several months.

A realistic expectation is:

• First few months: You may still need your usual allergy medicines.
• Buildup phase: Some people start noticing symptom improvement, but not everyone does.
• First year of maintenance: Many people who respond begin seeing more meaningful improvement.
• After 3 to 5 years: Some people have long-lasting relief even after stopping treatment.

If you have no improvement after about a year on maintenance therapy, your allergist may reassess your dose, allergen formula, diagnosis, environmental exposure, or other triggers such as smoke, irritants, chronic sinus disease, or nonallergic rhinitis.

Are faster allergy shot schedules available?

Some allergists offer accelerated schedules, sometimes called cluster or rush immunotherapy. These can help certain patients reach maintenance faster, but they require careful supervision and may not be right for everyone.

Do not try to speed up the schedule on your own. The timing and dose increases are part of the safety plan.

What to Expect at Your Allergy Shot Appointment

The injection itself is usually quick. The full appointment takes longer because of the required observation period after the shot.

Before the shot

Before each injection, clinic staff may ask whether you:

• Had a reaction after your last shot
• Have worsening asthma, wheezing, chest tightness, or shortness of breath
• Are sick, feverish, or recovering from an infection
• Started or changed any medications
• Are pregnant or trying to become pregnant
• Missed a recent allergy shot appointment
• Had unusual allergen exposure, such as heavy pollen exposure or a pet-heavy environment

Answer these questions honestly, even if you worry it might delay treatment. Your dose can often be adjusted safely, but the clinic needs accurate information.

Your allergist may also recommend taking an antihistamine before shots, especially if you tend to get local reactions. Do this only if your clinic recommends it.

During the injection

Allergy shots are usually given under the skin in the upper arm. Most people describe the injection as a quick pinch or sting.

Some patients receive one injection. Others receive more than one if they are being treated for multiple allergen groups that cannot be mixed in the same vial. Your allergist will explain your specific formula and schedule.

After the shot: the 30-minute rule

After each allergy shot, you should stay in the clinic for the observation period your allergist requires. For many practices, that means at least 30 minutes.

This waiting period matters because serious allergic reactions, while rare, are most likely to happen soon after the injection. Allergy clinics that administer shots should be prepared to recognize and treat reactions, including anaphylaxis, with medications such as epinephrine.

Do not leave early, even if previous shots were easy. Also ask your clinic what symptoms to watch for after you leave, because delayed reactions can happen.

Benefits of Allergy Shots

Allergy shots require commitment, but they can offer benefits that daily symptom medicines do not.

1. Allergy shots can reduce symptoms

For people who respond, allergy shots can reduce sneezing, congestion, runny nose, itchy eyes, postnasal drip, and allergy-triggered asthma symptoms. They are especially useful when symptoms are moderate to severe, last for a long season, or happen year-round.

2. Allergy shots may reduce reliance on daily medication

Many people start allergy shots because they are tired of depending on antihistamines, nasal sprays, eye drops, inhalers, or repeated urgent visits during allergy season.

You may still need medication during the first months of treatment, and some people continue using medication during peak exposure seasons. But successful immunotherapy can reduce the amount or frequency of medication needed for symptom control.

3. Allergy shots can provide lasting relief

One of the biggest advantages of allergy immunotherapy is durability. According to the AAAAI, allergy shots can lead to lasting relief for some people after treatment is stopped. That is why allergy shots are often described as disease-modifying rather than purely symptom-masking.

4. Allergy shots may help prevent allergic disease progression

Allergy immunotherapy may help prevent the development of new allergies and may reduce the risk that children with allergic rhinitis progress to asthma. This benefit is not guaranteed for every patient, but it is one reason allergists consider immunotherapy for children and teens whose allergies are clearly affecting quality of life.

5. Allergy shots can be cost-effective over time

Allergy shots have upfront costs: testing, serum preparation, office visits, injections, copays, and time away from work or school. But for some people, they may reduce long-term medication use, repeated doctor visits, missed workdays, and seasonal symptom burden.

The financial value depends on your insurance plan, clinic fees, symptom severity, and how consistently you complete treatment.

Risks and Potential Side Effects

Allergy shots are generally well tolerated when prescribed and administered correctly, but they are not risk-free. They contain allergens, so reactions are possible.

Mild local reactions

Local reactions are the most common allergy shot side effects. They can include:

• Redness at the injection site
• Itching
• Warmth
• Swelling
• Tenderness

These reactions can happen quickly or several hours after the injection. They are usually temporary. Tell your clinic if swelling is large, painful, increasing, or lasting longer than expected, because your allergist may adjust your dose or pre-shot plan.

Systemic reactions

A systemic reaction affects more than the injection site. Symptoms can include:

• Sneezing
• Nasal congestion
• Hives
• Itching away from the injection site
• Coughing
• Wheezing
• Chest tightness
• Nausea
• Dizziness

Systemic reactions are less common than local reactions, but they matter because they can become serious. Report any systemic symptoms immediately while you are in the clinic.

Severe reactions and anaphylaxis

Anaphylaxis is a rare but potentially life-threatening allergic reaction. Warning signs can include throat swelling, trouble breathing, wheezing, chest tightness, faintness, severe hives, vomiting, or a sudden drop in blood pressure.

This is the reason for the post-shot observation period. Allergy shot clinics should have trained staff and emergency medications available.

Call emergency services or follow your allergist's emergency plan if serious symptoms occur after you leave the clinic. If you have been prescribed an epinephrine auto-injector, use it as directed for symptoms of anaphylaxis.

Factors that can increase risk

Your allergist may be more cautious or delay a dose if you have:

• Poorly controlled asthma or current wheezing
• A recent systemic reaction to a shot
• A missed dose gap
• Fever or acute illness
• New medications that may affect reaction management
• Pregnancy during the buildup phase
• Significant heart disease or other conditions that make reactions harder to treat

This does not always mean you can never receive allergy shots. It means the risk-benefit decision needs to be individualized.

Who Is a Good Candidate for Allergy Shots?

Allergy shots may be worth discussing with an allergist if your symptoms are clearly linked to specific allergens and are not controlled well enough with avoidance and medication.

Allergy shots may be a good fit if you:

• Have moderate to severe seasonal allergies
• Have year-round indoor allergies from dust mites, mold, cockroach, or pets
• Have allergic asthma triggered by specific allergens
• Have allergic eye symptoms along with nasal allergies
• Have a history of systemic reaction to stinging insects
• Do not get enough relief from medication
• Have medication side effects, interactions, or a desire to avoid long-term daily medication
• Can commit to regular visits for several years

Who may need to avoid or delay allergy shots?

Allergy shots may not be started, or may require extra caution, in people with:

• Severe or uncontrolled asthma
• Inability to communicate symptoms after injections
• A health condition that makes anaphylaxis especially risky
• Certain medications, such as beta-blockers, that may complicate treatment of severe reactions
• Pregnancy before starting immunotherapy or while still increasing the dose
• Very young age, often under age 5, depending on the child and clinic
• Poor ability to follow the schedule or remain for observation after shots

Guidelines vary, and many situations require individualized judgment. For example, venom immunotherapy for stinging insect allergy may be considered even when other medical factors make routine environmental allergy shots more complicated, because the benefit can be substantial for high-risk patients.

Allergy Shots vs Other Allergy Treatments

Allergy shots are one option in a broader allergy care plan. They are not always the first step, and they are not the only form of immunotherapy.

Allergy shots vs antihistamines

Antihistamines can reduce itching, sneezing, and runny nose quickly, but they do not retrain the immune system. Symptoms usually return when the medication wears off or exposure continues.

Allergy shots vs nasal steroid sprays

Nasal steroid sprays are often very effective for allergic rhinitis and congestion. They can be part of your plan before or during allergy shots. Allergy shots may be considered when symptoms remain burdensome despite good spray technique and consistent use.

Allergy shots vs sublingual immunotherapy

Sublingual immunotherapy (SLIT) uses allergen tablets or drops under the tongue rather than injections. In the United States, FDA-approved SLIT tablets are available for only certain allergens. Allergy shots can cover a wider range of allergens, but they require in-office injections and observation.

An allergist can help compare allergy shots, SLIT, medication, avoidance, and asthma care based on your test results and goals.

Frequently Asked Questions About Allergy Shots

Are allergy shots permanent?

Allergy shots are not guaranteed to be a permanent cure. Many people have significant, long-term relief after completing a 3-to-5-year course, but some people relapse after stopping and may need additional treatment.

Can you get allergy shots while pregnant?

Allergists generally avoid starting allergy shots during pregnancy. If you become pregnant while already stable on maintenance therapy, your allergist may allow you to continue at the same dose. Dose increases are usually avoided during pregnancy because a severe reaction could create risk for both the pregnant patient and fetus.

Always involve both your allergist and OB-GYN in the decision.

How much do allergy shots cost?

The cost of allergy shots varies widely. Your total cost may include allergy testing, vial preparation, injection visits, follow-up visits, copays, deductibles, and coinsurance.

Many insurance plans cover part of allergy immunotherapy, but coverage varies. Before starting, ask your clinic and insurer about:

• Testing costs
• Serum or vial preparation fees
• Injection visit fees
• Specialist copays
• Deductible requirements
• Coverage limits
• Out-of-pocket maximums

Also consider nonmedical costs, such as travel time, parking, childcare, and time away from work.

What happens if I miss an allergy shot?

Call your allergy clinic and ask how to restart. Occasional missed shots are usually manageable, but your next dose may need to be repeated or reduced depending on how long it has been, what phase you are in, and whether you have a reaction history.

Do not try to make up missed doses by doubling up unless your allergist specifically instructs you.

Do allergy shots hurt?

Most people describe allergy shots as a brief pinch or sting in the upper arm. Mild soreness, itching, redness, or swelling can happen afterward.

If injections make you anxious, tell the clinic. They may be able to help with positioning, breathing techniques, scheduling, or practical steps that make visits easier.

Can children get allergy shots?

Yes, many children can receive allergy shots, especially children age 5 and older with allergic rhinitis, allergic asthma, or stinging insect allergy. Allergy shots are not typically recommended for very young children who cannot reliably cooperate with the schedule or describe symptoms after injections.

A pediatric allergist can help decide whether the benefits outweigh the burden and risks.

Can allergy shots make asthma worse?

Allergy shots can help some people with allergic asthma, but uncontrolled asthma increases the risk of serious reactions. Tell your clinic if you have wheezing, chest tightness, shortness of breath, recent rescue inhaler use, or an asthma flare before any shot.

Your allergist may check your asthma control, adjust the dose, delay the injection, or change your asthma plan.

Can I stop my allergy medicine once I start shots?

Not right away. Most people continue their usual allergy medicines during the early months of immunotherapy. As symptoms improve, your allergist may help you reduce medication gradually.

Do not stop asthma controller medication, nasal sprays, or other prescribed treatment without medical guidance.

Are allergy shots worth it?

Allergy shots may be worth it if your allergies are frequent, severe, expensive to manage, or interfering with sleep, school, work, exercise, or asthma control. They are less appealing if your symptoms are mild, easily controlled with occasional medication, or you cannot commit to regular visits.

The best answer depends on your allergy testing, symptom pattern, medical history, insurance coverage, and willingness to follow a multi-year plan.

Questions to Ask Your Allergist Before Starting

Bring a clear list of questions to your first immunotherapy visit. Helpful questions include:

• Which allergens will be included in my allergy shot formula?
• What symptoms are we trying to improve?
• What schedule do you recommend for the buildup phase?
• How often will I come in during maintenance?
• How will we measure whether treatment is working?
• What side effects should I expect?
• What symptoms should make me seek urgent care?
• Should I take an antihistamine before shots?
• What happens if I miss a dose?
• How will my asthma be monitored?
• What will my out-of-pocket cost likely be?
• When will we decide whether to continue, adjust, or stop?

Final Takeaway

Allergy shots are a long-term commitment, but they are one of the few allergy treatments designed to change the allergic response itself. For the right person, they can reduce symptoms, lower medication reliance, improve allergy-triggered asthma control, and provide relief that lasts beyond the treatment period.

The tradeoff is time, cost, and safety monitoring. You need regular appointments, patience during the buildup and maintenance phases, and a clinic that can manage reactions appropriately.

If your allergies are disrupting sleep, work, school, exercise, or asthma control, the next step is to talk with a board-certified allergist. You can use the AllergyAva allergist directory to find a specialist and ask whether subcutaneous immunotherapy is right for your allergy profile.

Medical Sources Used in This Guide

• AAAAI: Allergy Shots (Immunotherapy)
• AAAAI: Allergy Shot Tips
• AAAAI: Immunotherapy can Provide Lasting Relief
• Mayo Clinic: Allergy shots
• Journal of Allergy and Clinical Immunology: Allergen immunotherapy practice parameter third update
• AAO-HNSF: Clinical Practice Guideline: Immunotherapy for Inhalant Allergy
• Clinical and Translational Allergy: Contraindications to immunotherapy, a global approach
• AAAAI: Allergen Immunotherapy prior to conception and during pregnancy