Immunotherapy for Allergies: Allergy Shots vs. Sublingual Tablets Explained

What Is Immunotherapy for Allergies?

Immunotherapy doesn’t just mask allergy symptoms-it changes how your body reacts to them. Instead of reaching for antihistamines every spring, immunotherapy trains your immune system to stop overreacting to things like pollen, dust mites, or bee venom. It’s the only allergy treatment proven to potentially stop allergies from getting worse over time, and in some cases, even make them disappear.

This isn’t new. The first allergy shots were given in London in 1911. Today, two main types are used in the U.S.: allergy shots (subcutaneous immunotherapy) and sublingual tablets (SLIT). Both work the same way: expose you to tiny, controlled amounts of what you’re allergic to, slowly increasing the dose until your body no longer sees it as a threat.

How Allergy Shots Work

Allergy shots involve regular injections under the skin, usually in the upper arm. The process has two phases. First, the build-up phase: you get shots once or twice a week for several months, with each shot containing a slightly higher dose of your allergen. Once you reach the maintenance dose, you switch to shots every 2-4 weeks for 3 to 5 years.

Traditional build-up takes 3-12 months. But many clinics now offer cluster immunotherapy-getting multiple doses in one visit, spaced 30 minutes apart. This cuts the build-up phase to just 4-9 weeks. Rush immunotherapy, used mostly for severe insect sting allergies, gets you to maintenance in under two months, but it’s done in a hospital setting because of higher risk.

Each visit requires a 30-minute wait after the shot. That’s because there’s a small chance of a systemic reaction-like swelling, trouble breathing, or low blood pressure. That’s why shots are always given in a medical office. But serious reactions are rare: only about 2% of patients need epinephrine during build-up.

How Sublingual Tablets Work

Sublingual tablets are placed under the tongue and dissolved daily. No needles. No office visits. You take them at home, usually right after brushing your teeth. The FDA has approved four tablets so far: Oralair and Grastek for grass pollen, Ragwitek for ragweed, Odactra for dust mites, and Cat-PAD for cat dander (approved in April 2024).

Each tablet is designed for one allergen only. You start taking it months before allergy season (for grass or ragweed) or year-round (for dust mites and cat dander). The dose is fixed-you can’t adjust it. If you miss a day, you don’t double up. Just resume the next day.

Side effects are mild: itchy mouth or throat is common in the first few weeks, but it fades. Less than 1% of users have a serious reaction. No epinephrine is needed at home, but you’re told to take the first dose in a doctor’s office to make sure you’re okay with it.

Effectiveness: Shots vs. Tablets

When it comes to results, allergy shots win by a wide margin-if you have multiple allergies. Studies show shots reduce symptoms by 82% in patients with three or more allergens. Sublingual tablets? Around 67%.

Why? Because shots can be customized. A single vial can contain extracts from grass, ragweed, dust mites, and cat dander-all in one injection. Tablets? One allergen per pill. If you’re allergic to five things, you’d need five different tablets. That’s not practical. Most people don’t stick with it.

One Reddit user, ‘AllergyWarrior42,’ tried Grastek for two years and saw only 30% improvement. After switching to shots, they hit 80% relief by year two. That’s not unusual. In a survey of over 1,200 people who tried both, 68% said shots worked better.

But if you’re allergic to just one thing-say, grass pollen-and you hate needles, tablets are a solid choice. A 2022 patient survey found 92% preferred tablets for convenience. For busy parents, frequent travelers, or people who live far from an allergist, that matters.

Safety and Side Effects

Allergy shots carry a small but real risk of anaphylaxis. That’s why you must wait in the office after each shot. Cluster immunotherapy has a 4.7% rate of systemic reactions. Rush protocols? Up to 18%. But most reactions are mild and treated quickly with antihistamines or epinephrine.

Tablets are safer. Oral itching is common in the first week-about 28% of users feel it. But serious reactions? Less than 0.1%. No one has ever needed an EpiPen at home for a tablet reaction.

Still, tablets aren’t risk-free. If you have asthma that’s not well-controlled, you’re not a good candidate. The FDA requires patients to have stable asthma before starting any immunotherapy. And if you miss doses, effectiveness drops sharply. One trial showed that patients taking less than 80% of their tablets saw symptom relief drop to 45%.

Cost and Accessibility

Insurance usually covers both shots and tablets, but out-of-pocket costs vary. Shots can cost $50-$150 per visit, with 20-50 visits in the first year. Tablets cost $20-$40 per month, but you take them every day for years. Over five years, tablets might cost more-but you avoid travel, time off work, and waiting rooms.

Access is the bigger issue. There are only about 5,300 board-certified allergists in the U.S. Many rural areas have none. If you can’t get to a clinic weekly, shots aren’t realistic. Tablets? You can order them online and have them delivered.

Most allergists (92%) offer shots. Only 67% offer tablets. That’s changing. As new tablets get approved-for mold, cockroach, and other allergens-more clinics are adding them. But shots remain the standard because they’re more flexible and more effective.

Who Should Choose What?

Choose allergy shots if:

• You’re allergic to three or more things
• Your symptoms are severe or not controlled by meds
• You want the best chance at long-term relief
• You can commit to weekly visits for months

Choose sublingual tablets if:

• You’re allergic to just one thing (grass, ragweed, dust mites, or cat dander)
• You hate needles or can’t get to a clinic regularly
• You’re consistent with daily routines
• You’re okay with moderate symptom reduction

There’s no shame in either choice. But if you have multiple allergies and you’re not getting better with pills, shots are your best bet.

What’s Next for Allergy Immunotherapy?

The field is evolving fast. In 2025, multi-allergen sublingual tablets are expected to hit the market. Imagine one pill for grass, ragweed, and dust mites. That could change everything.

Also, new treatments are in trials that might cut treatment time from 5 years to just 1-2. These use purified allergen fragments (peptides) instead of whole extracts. Early results show promise.

Doctors are also using component-resolved diagnostics-testing for specific proteins in allergens, not just whole extracts. This helps match patients to the right treatment faster. If you’re allergic to a certain protein in cat dander, you’ll know exactly whether shots or tablets will help.

Real Talk: What Patients Say

On Google reviews, the most common phrase about allergy shots is “life-changing after two years.” People say they finally slept through the night. They stopped canceling plans. They could play with their kids without sneezing.

For tablets, the top comment is “easy to use.” One person wrote: “I take it while brushing my teeth. No appointments. No needles. I still get allergies, but not as bad.”

But don’t let convenience fool you. If you’re allergic to five things and you’re on a tablet for just one, you’re not getting full treatment. You’re just managing part of the problem.

Getting Started

First, see an allergist. They’ll do skin or blood tests to find out exactly what you’re allergic to. Then they’ll explain your options. If you have multiple allergies, they’ll likely recommend shots. If you have one and want convenience, tablets might be right.

Don’t rush. Immunotherapy takes years. But if you stick with it, you might not need to take allergy meds forever. That’s the goal.