Allergy shots can retrain your immune system over time
Allergy shots reduce allergy symptoms by building tolerance to triggers over time. See who benefits, what to expect, and care options—no referral.
Allergy shots are a long-term treatment that can make your immune system less reactive to specific triggers like pollen, dust mites, or pet dander. If your allergies keep breaking through medications, or you are tired of living around symptoms every season, shots can reduce how often you flare and how intense those flares feel. They work by giving you tiny, controlled doses of the thing you are allergic to, then slowly increasing the dose so your body learns to tolerate it. This article walks you through who they help most, how the testing and schedule usually work, what side effects are normal versus concerning, and how to make the time commitment easier. If you want help deciding whether shots fit your situation, PocketMD can talk it through with you in plain language, and labs can sometimes help rule out look-alike problems when symptoms are confusing.
Symptoms and signs you might notice
Seasonal sneezing and a runny nose
You might notice weeks where you cannot stop sneezing, your nose drips, and you feel congested even though you are not “sick.” This pattern often tracks with pollen seasons, which is why it can feel like you catch the same cold every spring or fall. When shots work, these cycles usually become milder and shorter over time.
Itchy, watery, or red eyes
Allergic eye symptoms can make you feel tired and distracted because your eyes burn, water, and itch all day. Rubbing makes it worse because it irritates the surface of the eye and spreads allergens around your eyelids. Immunotherapy can reduce how strongly your eyes react, but you still may need eye drops during high-exposure days.
Wheezing or chest tightness with allergies
If allergies trigger coughing, wheezing, or a tight chest, that can be a sign your airways are involved, not just your nose. This matters because uncontrolled airway symptoms raise the risk of more serious breathing trouble during a flare. Allergy shots are sometimes used to improve allergic asthma control, but your clinician will want your asthma stable before starting.
Sinus pressure and post-nasal drip
Thick drainage down the back of your throat can cause a chronic cough, a sore throat in the morning, or a “full” feeling in your face. It can also mess with sleep, which then makes everything feel worse the next day. Shots do not give instant relief, but they can reduce the baseline inflammation that keeps your sinuses irritated.
Reactions after an allergy injection
A small red, itchy bump at the injection site is common, especially as doses increase, and it often settles within a day. Some people feel more “allergy-ish” for a few hours afterward, like extra sneezing or mild wheeze, which is why clinics monitor you after each dose. If you ever develop trouble breathing, throat tightness, widespread hives, dizziness, or fainting after a shot, that is an emergency and you should get urgent care immediately.
Lab testing
If your “allergies” come with fatigue, frequent infections, or unexplained inflammation, a baseline check can help. Vitals Vault lab ordering includes a starting from $99 panel with 100+ tests, one visit.
Schedule online, results in a week
Clear guidance, follow-up care available
HSA/FSA Eligible
Causes and risk factors
Your immune system overreacts to harmless proteins
Allergies happen when your immune system treats something ordinary, like pollen, as if it is dangerous. Your body releases chemicals such as histamine, which leads to itching, swelling, mucus, and sometimes wheezing. Shots aim to change that pattern so your immune response becomes calmer and less explosive.
High exposure to a trigger you cannot avoid
If you live with a pet you are allergic to, work in a dusty environment, or spend time outdoors during peak pollen, avoidance may not be realistic. That constant exposure keeps your nose and eyes inflamed, which can make medications feel like they barely help. Immunotherapy is often considered when your life does not allow true avoidance.
Symptoms that persist despite good medication use
Some people take antihistamines, nasal steroid sprays, and eye drops correctly and still feel miserable. When you are already doing the basics and still missing sleep or work, shots become a “reduce the whole sensitivity” strategy rather than another add-on medication. The goal is fewer symptoms with less reliance on daily meds.
Allergic asthma or frequent flare patterns
If your allergies repeatedly set off coughing or wheezing, your airways may be primed to overreact. That can turn a normal exposure day into a day you avoid exercise, wake up at night, or reach for a rescue inhaler more often. Shots can help some people by lowering the allergic trigger load, but they need to be coordinated with an asthma plan.
Family history and other allergic conditions
If allergies, eczema, or asthma run in your family, your immune system may be more likely to develop allergic sensitivity in the first place. You might also notice you have more than one allergic problem, like nasal symptoms plus skin itching. Shots are usually targeted to the specific triggers that testing confirms are driving your symptoms.
How allergy shots are diagnosed and planned
A symptom story that matches exposure
Your clinician will start by connecting your symptoms to patterns, such as springtime flares, symptoms around cats, or congestion that worsens in a dusty bedroom. This step matters because not every “allergy” is truly allergy, and treating the wrong problem wastes months. A good history also helps decide whether shots are likely to pay off for you.
Skin prick testing in the office
Skin testing places tiny amounts of common allergens on your skin and checks for a raised itchy bump, which signals sensitivity. It is fast and often gives clear answers, but results need to match your real-life symptoms to be meaningful. The testing results guide exactly what goes into your shot mixture.
Blood allergy testing when skin testing is hard
A blood test can measure allergy antibodies (specific IgE) when you cannot stop antihistamines, have certain skin conditions, or have had severe reactions to testing in the past. It can be helpful, but it is not a perfect “yes or no” for how you will feel day to day. Your clinician still has to interpret it alongside your exposure and symptoms.
Safety check before you start
Before shots, clinicians usually review asthma control, heart conditions, pregnancy status, and medications that can complicate treatment, such as certain blood pressure drugs. This matters because the rare severe reaction needs to be treated quickly and effectively if it happens. You will also be told to stay for an observation period after each injection, because that is when serious reactions are most likely to show up.
Treatment options and what to expect
Build-up phase: weekly dose increases
Most people start with very small doses and come in frequently, often weekly, while the dose is gradually increased. This phase is where you are most likely to notice local swelling at the injection site because your immune system is still learning. It is a time commitment, but it is also the fastest way to reach a dose that can actually change symptoms.
Maintenance phase: less frequent shots
Once you reach a stable target dose, visits usually spread out, often to every few weeks. This is when many people start noticing fewer bad days and less need for extra medication, although improvement can be gradual. Staying consistent matters because long gaps can force dose reductions and slow progress.
Medications while shots do their job
Shots are not an instant fix, so you may still need antihistamines, nasal sprays, or asthma medications during the first months. Think of meds as symptom control and shots as immune retraining, which means they can work together. Many people find they can step down medication later, but that decision should be guided by how you are actually feeling and breathing.
Managing side effects and reaction risk
A small itchy lump where the shot went in is common, and a cool compress or an antihistamine can help if your clinician says it is okay for you. More significant symptoms, like widespread hives, throat tightness, or shortness of breath, are uncommon but serious, which is why you are observed after each dose. If you feel “off” later the same day, call the clinic for guidance before your next injection so dosing can be adjusted safely.
Alternatives: allergy tablets or avoidance plans
For some allergens, under-the-tongue immunotherapy tablets (SLIT) can be an option, especially for certain pollens, and they avoid injections. If your triggers are limited and avoidable, a strong home and workplace exposure plan plus medications may be enough. The best choice depends on what you are allergic to, how severe your symptoms are, and how feasible regular visits are for you.
Living with allergy shots day to day
Plan around the time commitment
Shots work best when you can show up consistently, so it helps to pick a clinic location and appointment time you can keep even during busy weeks. If you travel often, ask early about transferring vials or coordinating schedules, because last-minute gaps can set you back. A predictable routine makes the whole process feel less like it is running your life.
Know what to do on shot days
Many clinics recommend avoiding strenuous exercise right before and after your injection because increased blood flow can make reactions more likely or more intense. You will also want to arrive well, not feverish, because getting a shot while you are sick can complicate how your body responds. If you have asthma, bring your rescue inhaler and mention any recent wheezing before you get dosed.
Track progress in a simple way
Progress can be subtle, so it helps to track something concrete, like how many days per week you need antihistamines or how often you wake up congested. Over a few months, those small changes add up and make it easier to decide whether the treatment is paying off. If nothing is improving after a reasonable trial, that is a useful data point to bring back to your allergist.
Keep your exposure plan anyway
Even when shots are working, heavy exposure can still overwhelm your system, especially during peak pollen or in a dusty indoor space. Simple steps like bedroom allergen control and rinsing pollen off your face and hair after outdoor time can reduce breakthrough symptoms. Think of shots as raising your threshold, not making you invincible.
Prevention and reducing flare-ups
Reduce indoor allergens where you sleep
Your bedroom is where you spend hours breathing the same air, so small changes can have an outsized effect. Dust-mite control measures, washing bedding in hot water, and keeping humidity reasonable can lower the trigger load. When your baseline inflammation is lower, shots and medications tend to work better.
Time outdoor activity to pollen patterns
Pollen counts often peak at certain times of day and on windy, dry days, which can turn a jog into a symptom explosion. If you shift outdoor workouts to lower-count times and shower afterward, you can cut down on how much allergen stays on your skin and hair. This does not replace shots, but it can make the waiting period for improvement more comfortable.
Treat nasal inflammation early in the season
If you know your allergy season, starting your nasal spray or other plan before symptoms are raging can prevent the “snowball” effect of swelling and mucus. Once your nose is very inflamed, it is harder to breathe, sleep, and think clearly, and you may need more medication to catch up. Early control also reduces the chance that post-nasal drip turns into a lingering cough.
Stay consistent with maintenance dosing
The protective effect of shots depends on steady exposure to the maintenance dose over time. When you miss multiple visits, your clinic may need to lower your dose for safety, which can slow your momentum. If your schedule is changing, it is better to plan ahead with the clinic than to disappear and restart later.
Frequently Asked Questions
How long do allergy shots take to work?
Some people notice small improvements during the build-up phase, but meaningful change often takes several months on maintenance. The full benefit is usually judged over 1–2 years because your immune system changes slowly. If you are not seeing any trend at all after a sustained period, ask whether the trigger selection or dosing plan needs revisiting.
Are allergy shots safe?
They are generally safe when given in a medical setting with post-shot observation, but they can cause reactions because you are being exposed to an allergen on purpose. Local redness and swelling are common, while severe reactions are uncommon but can be serious. That is why clinics screen for uncontrolled asthma and monitor you after each injection.
Can I get allergy shots if I have asthma?
Yes, shots can be used in people with allergic asthma, especially when allergens clearly trigger symptoms. The key is that your asthma should be stable, because poorly controlled asthma increases the risk of a serious reaction. Tell the clinic about any recent wheezing, nighttime symptoms, or increased rescue inhaler use before you get dosed.
Do I have to stop allergy medicines before testing or shots?
You often need to stop antihistamines before skin testing because they can blunt the skin reaction and make results misleading. For shots themselves, many people continue their usual medications, especially early on, because shots are not immediate relief. Your allergist will give specific instructions based on what you take and how you react.
What if my symptoms aren’t really allergies?
Chronic congestion and cough can also come from non-allergic rhinitis, reflux, infections, or irritants, which is why a careful history and testing matter before committing to shots. If your symptoms include unusual fatigue, frequent infections, or inflammation that does not fit a typical allergy pattern, basic labs can sometimes help rule out other contributors. Getting the diagnosis right up front saves you time and frustration.