Do Allergy Drops Have Side Effects? What You Need to Know

Allergy drops, known scientifically as sublingual immunotherapy, are gaining traction as a preferred method for treating various allergies due to their convenience and effectiveness. However, understanding the potential side effects is crucial for anyone considering this treatment. This blog aims to shed light on the side effects associated with allergy drops, providing a balanced view to help you make a well-informed decision about your allergy management strategy.

Understanding Allergy Drops

Allergy drops work by introducing small amounts of an allergen to the body in a controlled manner, aiming to build up tolerance and reduce allergic reactions. This method is distinct from traditional allergy shots, offering the convenience of at-home administration. It's important to understand that, like any medical treatment, allergy drops can have side effects, although they are typically less severe than those associated with allergy shots.

Common Side Effects of Allergy Drops

  1. Oral Irritation: The most frequent side effect involves discomfort in the mouth or under the tongue. Symptoms like itching, mild swelling, or a tingling sensation are usually not severe and tend to diminish as the body adjusts to the treatment.
  2. Gastrointestinal Symptoms: Some individuals might experience gastrointestinal discomfort, including nausea or stomachaches. These symptoms are generally mild and often resolve as the body becomes accustomed to the treatment.
  3. Allergic Reactions: Allergic reactions, particularly local ones such as swelling or itching in the mouth, can occur. Systemic reactions are less common but can include symptoms like hives, breathing difficulties, or a drop in blood pressure.
  4. Taste Changes: A less common side effect is a change in taste or a mild metallic taste in the mouth immediately after taking the drops, which typically resolves quickly.

Managing Side Effects

  1. Communication with Your Allergist: It's essential to maintain open communication with your allergist, especially if you experience any side effects. They can adjust the treatment plan accordingly, whether by altering the dosage or changing the administration technique.
  2. Monitoring Symptoms: Careful observation of how your body reacts to allergy drops, particularly in the early stages of treatment, is important. Noting any changes or discomfort can help your allergist tailor the treatment to your needs.
  3. Adherence to Instructions: Proper administration of allergy drops is crucial. Incorrect use can increase the likelihood of side effects. Ensuring that the drops are used as directed, typically under the tongue, and held for the recommended time before swallowing, can minimize adverse effects.

Rare but Serious Side Effects

Serious side effects are uncommon with allergy drops, but they can occur. Anaphylaxis, a severe allergic reaction, is extremely rare but is a medical emergency. Understanding the signs of a severe allergic reaction and knowing when to seek immediate medical attention is vital.

Safety Profile of Allergy Drops

Allergy drops are generally well-tolerated and have a favorable safety profile, particularly when compared to allergy shots. The risk of severe reactions is lower, making them a suitable option for many, including those who are averse to needles or have certain medical conditions that preclude the use of traditional allergy shots.


Allergy drops are an effective, convenient treatment option, but awareness and understanding of potential side effects are crucial. Most side effects are mild and manageable, and the overall risk profile is low. Being informed and working closely with your allergist can ensure a safe and effective treatment experience.

Considering allergy drops for your allergy management? Consult with our experienced allergists to discuss the benefits and risks, and to create a treatment plan tailored to your individual needs and health profile.

Frequently Asked Questions About Side Effects of Allergy Drops

Are there any immediate side effects after taking allergy drops?
The most common immediate side effect is mild oral irritation, such as itching or a tingling sensation under the tongue. This usually subsides shortly after taking the drops.

Can allergy drops cause severe allergic reactions?
Severe allergic reactions to allergy drops, like anaphylaxis, are extremely rare. However, it's important to be aware of the signs and seek immediate medical attention if they occur.

Will I experience gastrointestinal issues with allergy drops?
Some individuals may experience mild gastrointestinal symptoms like nausea or stomach discomfort, especially at the beginning of the treatment. These symptoms generally decrease with continued use.

Is it common to have a change in taste after taking allergy drops?
A change in taste or a metallic taste in the mouth immediately after taking allergy drops is possible but less common. This usually resolves quickly and is not a cause for concern.

Should I stop taking allergy drops if I experience side effects?
If you experience side effects, it's important to consult with your allergist before making any changes to your treatment. They can adjust your dosage or provide guidance on how to manage the side effects.

How can I minimize the side effects of allergy drops?
Adhering to the correct administration technique and following your allergist's instructions can help minimize side effects. Also, monitoring your body's reaction and communicating any concerns to your allergist is crucial.

How long do side effects from allergy drops last?
Most side effects are temporary and will lessen as your body adjusts to the treatment. The duration can vary, but ongoing or severe symptoms should be discussed with your allergist.