What are “allergy drops”?

Allergy drops are an alternative to allergy shots. Both treatments are options for treating allergies at their cause.

While allergy shots involve injecting small doses of allergen under your skin with a needle, allergy drops are taken by mouth.

Allergy drops (SLIT)Allergy shots (SCIT)
Sublingual immunotherapy (SLIT). Sublingual just means “under the tongue” and involves tablets or liquid drops that are dissolved in the mouth.Subcutaneous immunotherapy (SCIT). Subcutaneous means “under the skin” and involves shots or injections given by a healthcare provider.

How allergy drops work

SCIT and SLIT are forms of allergen immunotherapy. Allergen immunotherapy refers to repeatedly exposing you to small doses of something you’re allergic to (allergen) to make you less sensitive to it. When the allergen is given to you by placing it under your tongue, it’s called sublingual immunotherapy (SLIT) or “allergy drops”.

Unlike antihistamines and other medications that treat allergy symptoms, immunotherapy treats the condition itself.

When your body is exposed to a moderate to large amount of something you’re allergic to, your immune system tries to get rid of it. This causes the familiar symptoms of allergic rhinitis, like sneezing, runny nose, and watery eyes.

On the other hand, repeated exposure to small but increasing doses of allergen desensitizes your immune system. Eventually, your body becomes tolerant of the allergen, so you get fewer or less severe symptoms when exposed to larger amounts of it.

The takeaway

Allergy drops, like other forms of immunotherapy, treat the cause and not just symptoms of allergies.

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Allergy drops cover these allergies

Treatment with allergy drops has only been approved by the FDA for four allergens. They are:

Allergy drops benefits

Good for allergic rhinitis

A comprehensive review of published studies revealed there is a lot of good evidence that allergy drops are safe and effective for treating allergic rhinitis. SCIT was also safe and effective, but there wasn’t enough evidence to determine if allergy drops are more effective than SCIT.

Fewer side effects than from shots

A paper reviewing the safety of immunotherapy used to treat allergic rhinitis showed the chance of severe reactions is much lower for allergy drops compared to SCIT (allergy shots).

Allergic reactions less severe or gone for years

A review of published studies showed that symptom relief continued for two to three years after allergy drop treatment was stopped after being taken for three years.

A lot of research has been done using allergy drops to treat a variety of allergens, but more is needed to determine its overall safety and effectiveness.

Forms of allergy drops

Allergy drops may come in liquid or tablet form.

Currently, all allergy drops approved by the FDA are in tablet form. The FDA is still evaluating the safety and efficacy of the liquid form and hasn’t approved it yet. In the United States liquid drops are still used by some doctors but only as off-label drugs.

How allergy drops are administered

After your healthcare team has performed allergy testing to determine exactly what you’re allergic to, you’ll be treated with a tablet containing an extract of your specific allergen.

The first time

Your first dose of allergy drops should be given at your doctor’s office.

  • The tablet is placed under your tongue where you hold it until it’s dissolved.
  • You shouldn’t swallow for one minute or eat or drink for five minutes afterward.
  • You’ll be watched for 30 minutes after taking the tablet in case you have a severe reaction. It’s unlikely, but it’s important that you have medical help available if it does happen.

After the first time

If you tolerate the first allergy drop, you’ll give the rest of the allergy drops to yourself at home.

How often, how long, and symptom relief

Most allergy drops are taken every three to seven days for three years. You’ll usually have no or only minimal allergy symptoms the fourth year. Some people continue without symptoms indefinitely, but most have to start another course of allergy drops after two or three years because symptoms return.

If you have seasonal allergies (hay fever), you’ll start using the allergy drops three to four months before allergy season starts and continue taking them until it ends. If you’re allergic to something that’s around all the time, like I dust mites, you’ll take them throughout the year.

Your allergy symptoms should begin to improve within a few months of starting allergy drops but getting the full benefit may take a year or more.

In case of emergency

Since you give yourself the tablets at home, you should get written instructions about when to contact your doctor and how to identify and manage any possible side effects. Your doctor will also prescribe epinephrine that can be self-injected in case you have an anaphylactic reaction.

You shouldn’t take allergy drops if you have severe asthma because they can set off an asthma attack.

Allergy drops vs allergy shots

Allergy drops pros

  • no needles or injections
  • can be taken at home
  • fewer side effects including potentially lower risk of anaphylaxis
  • may be less expensive because taken at home
  • more acceptable to children
  • takes less time overall

Allergy drops cons

  • usually only one allergen per tablet
  • medications for only four allergens are FDA approved
  • long-term safety and efficacy not fully known or researched yet
  • requires compliance with taking the medication
  • must be taken daily
  • may not be covered by insurance

SCIT pros

  • can include multiple allergens in one shot
  • FDA-approved for most allergens
  • long-term safety and efficacy are known and well-researched
  • have been used for many years
  • only receive it one to two times a week or month

SCIT cons

  • requires needles and injections
  • have to go to doctor’s office to get them
  • more side effects including potentially higher risk of anaphylaxis
  • more expensive because of office visits
  • may not be acceptable to children

Allergy drops and food allergy treatments

Allergy drops might also be effective for food allergies, but a lot less research has been done on it compared to oral immunotherapy (OIT).

OIT is another method used to desensitize you to an allergen. But it’s only used for allergies to food, especially peanuts. It’s similar to allergy drops, but instead of the allergen being in a tablet that’s put under your tongue, you’re given tiny amounts of the food allergen to eat.

An article comparing OIT and allergy drops have found that OIT works better but has more side effects. Using both methods together may give a better result with fewer side effects. More studies are needed.

OIT is also not FDA approved. According to the American Academy of Allergy, Asthma & Immunology, while we can’t know if or when a standardized OIT product would be developed by anyone or approved by the FDA, the most likely would be for peanut allergy.

Allergy drops side effects

Side effects most often occur during the first week of treatment. Many are usually mild. Side effects include:

  • throat irritation
  • itchiness of your lips, inside of your mouth, or of your ears
  • sores on your tongue or in your mouth
  • swelling of your tongue or the inside of your mouth

Less common, more severe reactions

Rarely, nausea, vomiting and abdominal pain occur.

A severe life-threatening body-wide allergic reaction called anaphylaxis rarely occurs. Symptoms come on suddenly and include:

  • shortness of breath
  • wheezing
  • low blood pressure
  • fast or irregular heart rate
  • throat swelling
  • confusion
  • loss of consciousness
  • shock

Anaphylaxis should be treated as soon as possible by self-injecting epinephrine and then calling 911.

The takeaway

Allergy drops can be very effective for treating allergic rhinitis due to ragweed, some grasses, and dust mites. They are as effective as allergy shots and are associated with fewer side effects. Currently there are only four types FDA-approved allergy drops, although other types are used as off-label drugs.

Allergy drops may be an excellent alternative to allergy shots for you if you don’t like shots or don’t have time for frequent visits to the doctor’s office.