If you have an overactive immune system, your doctor may recommend mast cell stabilizers as a potential treatment option.

The immune system plays an essential role in keeping people healthy. But, when it’s not functioning properly, it can cause a lot of problems. Mast cell overactivation is one of those issues. It can cause allergy-like symptoms that can be difficult to stay on top of.

If you are struggling with an immune condition, taking mast cell stabilizers can be an effective way to reduce symptom frequency and severity.

We wrote this article to explore everything you need to know about mast cell stabilizers, including the common types, how they work, and important side effects to watch out for.

Here’s the breakdown.

What are mast cell stabilizers, and how do they work?

Mast cells are a type of white blood cell, and they play an important role in the body. They help the body respond to infections, support wound healing, and act as an early warning system when something potentially harmful is detected.

When triggered, they release chemical mediators, including histamine, cytokines, prostaglandins, and leukotrienes. This is a normal part of the immune response. However, when this process becomes overactive or dysregulated, it can lead to inflammation and unwanted effects, such as allergy-like symptoms.

Mast cell stabilizers specifically target and inhibit the release of these chemical mediators from the mast cells.

They are typically prescribed to manage:

• Mild to moderate asthma
• Inflammation of the nasal passageway (allergic rhinitis)
• Eye infections (conjunctivitis)
• Mast cell conditions like mastocytosis and mast cell activation disorder (MCAS)

Depending on the mast cell stabilizer you are prescribed, it can take multiple weeks of consistently taking the medication before you experience the peak benefits. This is because they inhibit the release of chemical mediators rather than blocking their activity directly.

Types of mast cell stabilizers

Mast cell stabilizer is an umbrella term for a variety of medications, each with its own function, mechanism of action, and side effects.

Here, we break down some of the most commonly prescribed mast cell stabilizers.

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Cromolyn sodium

Cromolyn sodium (Gastrocrom®) can be taken in four different ways:

• Oral solution
• Nasal spray
• Eye drops (ophthalmic solution)
• Inhalation solution (through a nebulizer or inhaler)

On average, it takes up to four weeks for people taking cromolyn sodium to experience the full benefits of the medication.

Most people tolerate cromolyn sodium well, but people living with mast cell activation disorders may note symptoms that feel stronger or longer-lasting. This can make it harder to tell what’s related to the medication. Closely monitoring and tracking symptoms is the best way to evaluate the efficacy of this medication over time.

Some of the most common side effects of cromolyn sodium are headache and diarrhea, but these are still rare.

Other possible side effects include:

• Nausea or stomach discomfort
• Abdominal pain
• Itching or rash
• Muscle aches

Less commonly, people report dizziness, palpitations, or changes in mood or sleep, though it’s not always clear if these are caused by the medication.

Speak to your doctor if side effects are persistent or getting worse. Seek urgent care for chest pain, severe shortness of breath, or signs of an allergic reaction.

Ketotifen

Ketotifen (Zaditen®) is an antihistamine with mast-cell-stabilizing properties. It is commonly used in allergic conditions and, in some countries, for asthma or mast cell disorders.

Side effects of ketotifen to watch for include:

• Drowsiness or sedation
• Headache
• Increased appetite or weight gain
• Dry mouth
• Nausea or gastrointestinal discomfort
• Fatigue
• Irritability or sleep disturbances (less common)

In rare cases, more serious side effects may occur, including:

• Severe skin reactions (blistering or peeling skin)
• Liver-related changes (yellowing of the skin or eyes)
• Seizures or severe confusion
• Unusual bruising or changes in blood counts

Seek medical advice quickly if you notice any unusual or severe symptoms.

It is possible to overdose on ketotifen. If you or someone you love is taking ketotifen and becomes disoriented, has heart palpitations, seizures, abnormal movements, or loses consciousness, call the emergency medical services immediately.

Aspirin therapy

Acetylsalicylic acid (usually called aspirin) is a nonsteroidal anti-inflammatory drug (NSAID). It helps reduce inflammation in the body. It is taken orally as a tablet.

Besides reducing pain, aspirin blocks the production of prostaglandins, a chemical mediator released by mast cells

Taking aspirin can help to reduce flushing symptoms associated with mast cell activation disorders.

Potential side effects from taking aspirin you should monitor include:

• Headaches
• Nausea
• Abdominal discomfort
• Blood in the stool
• Bruising easily
• Rashes or blisters
• Allergic reactions
• Hearing loss or ringing in the ears
• Signs of kidney or liver injury

Despite being an over-the-counter medication, you should only start taking regular aspirin therapy for allergy symptoms after consulting your doctor.

Supplements

Some people experience improvements in their symptoms by taking health supplements that are known for their anti-inflammatory properties.

Here are some examples:

• Bioflavonoids, including quercetin and luteolin
• Vitamin C
• Vitamin D
• Stinging nettle
• Curcumin

Important note: Supplements are not an FDA-approved or monitored product. It is possible to overdose or react to some supplements, and if you are living with a mast cell activation disorder, the ingredients could trigger severe symptoms. Always speak with your doctor before starting a supplement to check it’s safe for you.

Taking mast cell stabilizers safely

Like any other type of medication, mast cell stabilizers are not suited for all people. Before you start mast cell stabilizer therapy, be sure to alert your doctor if you have a medical history of any of the following conditions:

• Kidney disease
• Liver disease
• A history of any strong allergic reactions
• If you are breastfeeding, pregnant, or planning a pregnancy

If you take medications for other medical conditions, be sure to review those with your doctor before starting a mast cell stabilizer or supplement. It’s important to check for possible contraindications.

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Frequently asked questions

Which medications are mast cell stabilizers?

Some of the most commonly prescribed mast cell stabilizers include cromolyn sodium (Gastrocrom®), ketoifen (Zaditen®), acetylsalicylic acid (Aspirin), and dietary supplements high in bioflavonoids.

Can Zyrtec® stabilize mast cells?

Zyrtec® is a second-generation H1 antihistamine, not a mast cell stabilizer. However, it does help reduce mast cell overactivation. Because it blocks histamine receptors in the body, it can help reduce the severity of allergy symptoms in people with overactive mast cells.

Can I stabilize my mast cells naturally?

Health supplements such as quercetin, luteolin, vitamin C, vitamin D, stinging nettle, and curcumin can be used to naturally reduce the amount of histamine released by mast cells. However, evidence for their effectiveness is still limited, and responses can vary from person to person.

It’s important to speak with your doctor before starting any mast cell stabilizing supplement to ensure it’s safe to consume alongside your other treatments.

Disclaimer: Human Health is a health tracking platform and does not provide medical advice, diagnosis, or treatment. The information on this site is intended to support, not replace, conversations with qualified healthcare professionals.

Sources:

1. Twenty-first century mast cell stabilizers (2013)
2. Mast Cell Stabilizer, ScienceDirect
3. Mast cell stabilizers: from pathogenic roles to targeting therapies (2024)
4. Mast cell stabilizers, Science Direct
5. Label: GASTROCROM, cromolyn sodium liquid, DailyMed
6. Cromolyn Sodium (2024) 
7. Ketotifen, PubChem
8. Aspirin, Cleveland Clinic‍
9. Supplements, Mast Cell Action