Sublingual Immunotherapy (SLIT) FAQs

Allergy drops, or sublingual immunotherapy (SLIT), are liquid drops mixed from a variety of allergy extracts and formulated specifically to a patient’s underlying allergy profile. They are administered daily at home, placed under the tongue and held there for approximately two minutes after administration.

Allergy drops are different from allergy medications in that they are formulated specifically for the patient based on what they are allergic to. They are administered in gradually increasing doses to induce allergic tolerance in the patient’s immune system. This has the effect of modifying the patients immune system and reducing or eliminating the symptoms patients feel with exposure to allergens on a permanent basis. They are not designed or effective for immediate relief of symptoms.

One of the key differences between allergy shots and drops is the route of administration. Allergy shots (Subcutaneous Immunotherapy or SCIT) are given via an injection underneath the patient’s skin, whereas allergy drops are placed under the tongue. The allergy extracts that are used for both are the same, although the dosing and the frequency at which they are administered are different. Allergy drops are used daily, whereas allergy shots can be spaced out anywhere from 1-4 weeks depending on the treatment plan. Allergy shots must be safely administered in an office setting while allergy drops can be safely administered at home.

In general allergy drops are well tolerated and have minimal side effects. However, there are some potential risks to be aware of. The most common side effects patients report are mild and include mild itching, swelling, irritation, or numbness of the mouth or tongue.  Less commonly, gastrointestinal symptoms have been reported. In very rare cases this can progress to a reaction that involves the entire body. The risks involved with allergy drops are less than those involved with allergy shots, although allergy shots are also generally safe and well tolerated. Allergy shots should be safely administered in an office setting, whereas allergy drops can be safely administered at home.

Although the allergy extracts used for allergy drops are the same as those used for allergy shots, the FDA has not approved sublingual administration (under the tongue). Use of specific allergy extracts under the tongue has recently received FDA approval in tablet form, but only for a select few select allergens. Sublingual immunotherapy has been successfully used both in the US and abroad for many years. 

Allergy drops are similar to allergy shots in terms of effectiveness in controlling allergy symptoms, and both have been shown to provide long term improvement even after the treatment has ended. However, the treatment is only effective for the allergen contained in allergy shots or drops. There is a significant correlation with the drops effectiveness and the dose of the allergen given. It is important to work with your board certified Allergist to develop a tailored treatment plan that works for you.

Allergy drops can be safe and effective for many allergy sufferers, and there are a few people who typically do especially well. These include those with a fear of needles, most children, and patients who have difficulty adhering to allergy shot protocols. Patients who should probably not take allergy drops include those with severe uncontrolled asthma, patients with a history of eosinophilic esophagitis, and those with a history of severe allergic reactions to allergy drops in the past. You should discuss with your board certified Allergists if allergy drops are the right solution for you. 

Allergy drops can be given for all types of airborne allergens including pollens, cat dander, dog dander, dust mites, and molds. They are not currently recommended for food allergies, allergies to stinging insects, or allergies to medications.

Like allergy shots, most people we’ll see improvement in the first 3 to 6 months of treatment. The current recommendations are to take allergy shots or allergy drops for a total of 3 – 5 years in order to have a sustained and long-lasting effect.  

Because allergy drops are not FDA approved insurance companies do not currently cover the cost of allergy drops. Allergy drops do in most cases qualify for HSA or flex spending account reimbursement as they are a valid and accepted medical treatment prescribed by your board certified Allergist.