The shots themselves are pretty straightforward, experts say—you can expect an injection in the skin of your arm, like a flu shot—but this isn’t a one-and-done treatment. “The difficult part is showing up,” Dr. Agarwal says. During the so-called “buildup phase,” you’ll need to be at your allergist’s office weekly (and maybe even multiple times a week!) for injections that gradually ramp up in dosage. This stage usually takes about three to six months, but it can last as long as 10 depending on the dose you’re given.
Next comes the “maintenance phase”: At this point, your injections will probably be bi-weekly and eventually monthly. But you’ll have to continue showing up for years to maintain your results—three to five is pretty typical, according to the American College of Allergy, Asthma & Immunology. And this phase, too, can last longer for some people.
All to say that it won’t exactly be a breeze to build this treatment into your schedule. So if OTC meds are working reasonably well, the time commitment may not be worth it for you.
If you are a candidate for SLIT, there’s one big advantage: You can take the tablets or drops at home, which means no schlepping to the doctor’s office for years.
You may still need to take antihistamines.
Around 80% of people who get allergy shots see a major improvement, while 60% continue to experience benefits years later. But while some people are lucky enough not to need OTC meds after finishing their injections, others may still need to take antihistamines from time to time.
If your symptoms were really severe or treatment-resistant, allergy shots may still feel well worth the effort in the end. But if they appeal to you primarily because you don’t want to always be taking medication, you should know that there’s a chance you still might have to.
You also might not experience immediate results. While symptoms start easing for some people during the buildup phase, “it may take as long as 12 to 18 months on the maintenance dose for others to notice,” says Dr. Agarwal.
They don’t work for all allergies.
Sadly, this type of immunotherapy won’t help if you react to foods, like peanuts. They seem to work best for environmental allergies, like those triggered by dust mites, mold, and seasonal allergens like grass, weeds, and trees. They can also help with allergic asthma or insect stings. So if you have a severe reaction to bee, hornet, or wasp stings, which can be pretty scary and require an Epi-Pen jab, you might go this route.
If you love to be around cats or dogs but they trigger your symptoms, there’s less evidence that the shots will do the trick, according to Dr. Doherty, although some doctors still recommend them. “There is some positive data to support their use for pet allergies in the right patients,” he says. Your doc may also suggest off-label SLIT droplets, since these may help cat and dog allergies.
There’s a small risk of a reaction.
Luckily, it’s rare to experience a serious reaction to allergy shots. But because the injections do contain tiny amounts of allergen, it’s possible to have one. To be safe, your doctor will ask you to stay at the office for at least 30 minutes after each injection to keep an eye out for things like hives, itching, wheezing, and shortness of breath. (This, too, adds to the overall time commitment!)
They can be expensive.
If heading to the doctor like four times a month for years on end sounds like you could be drowning in co-pays (if you even have health insurance), you would be correct.