Understanding Mast Cell Activation Syndrome (MCAS): Medications and Natural Support Options

Dr. Rachel Erickson, Naturopath, L.Ac.

Mast Cell Activation Syndrome (MCAS) happens when your immune cells release too many inflammatory chemicals, leading to symptoms like fatigue, itching, and brain fog. Dr. Rachel Erickson, ND, LAc, shares how a mix of medications, nutrition, and natural therapies can help calm the body, reduce inflammation, and restore balance.

What Is MCAS?

Mast Cell Activation Syndrome (MCAS) is a condition where the body’s mast cells — part of your immune system — release too many inflammatory chemicals, called mediators.
These mediators include histamine, tryptase, prostaglandins, and cytokines, which can cause a wide range of symptoms that seem unrelated at first glance.

People with MCAS often experience:

Flushing, itching, hives, or swelling
Abdominal pain, nausea, or diarrhea
Brain fog, anxiety, or fatigue
Sensitivity to heat, foods, or fragrances
Lightheadedness or low blood pressure

MCAS overlaps with conditions like POTS (postural orthostatic tachycardia syndrome), Ehlers-Danlos syndrome, chronic infections, and long COVID, and it’s often triggered by chronic stress, infections, toxins, or hormonal changes.

Conventional Medications for MCAS

There’s no single “MCAS pill.” Treatment typically involves stabilizing mast cells and blocking the mediators they release.
Many patients do best with a combination approach that’s carefully introduced in low doses.

1. Antihistamines

H1 blockers: Cetirizine (Zyrtec), Loratadine (Claritin), Fexofenadine (Allegra), Diphenhydramine (Benadryl)
H2 blockers: Famotidine (Pepcid), Ranitidine (discontinued in the U.S.)
These help reduce flushing, itching, and GI symptoms.

2. Mast Cell Stabilizers

Cromolyn sodium (Gastrocrom) – reduces mast cell degranulation, often used for gut and systemic symptoms.
Ketotifen – an H1 blocker with stabilizing effects; available by prescription or compounding pharmacy.

3. Leukotriene Inhibitors

Montelukast (Singulair) or Zileuton – may reduce respiratory or inflammatory symptoms.

4. Low-Dose Naltrexone (LDN)

Modulates immune activity and may calm mast cell overactivation in some patients.

5. Other options

Quercetin, aspirin (low dose), or omalizumab (Xolair) in refractory cases under specialist supervision.

Natural & Integrative Support for MCAS

While medications can control symptoms, natural therapies address the underlying inflammation, gut health, and nervous system sensitivity that keep mast cells overactive.

1. Anti-Inflammatory Diet

Focus on whole, low-histamine foods: fresh meats, non-citrus fruits, steamed vegetables, olive oil.
Avoid fermented foods, aged cheese, alcohol, and leftovers, which can increase histamine load.
Identify personal triggers through an elimination or low-histamine diet.

2. Key Nutrients

Vitamin C – helps degrade histamine and stabilize mast cells.
Vitamin D – modulates immune function.
Magnesium – supports nervous system balance and reduces reactivity.
Zinc – helps regulate immune signaling.

3. Natural Mast Cell Stabilizers

Quercetin: a bioflavonoid that calms mast cells and reduces histamine release.
Luteolin: often combined with quercetin for brain and neuroinflammation symptoms.
Bromelain: enzyme from pineapple that may reduce allergic inflammation.
Curcumin: from turmeric, lowers NF-κB activity and histamine-related inflammation.

4. Gut Health & Microbiome Balance

Leaky gut and dysbiosis can perpetuate immune overactivation.

Use low-FODMAP, low-histamine diets, probiotics (carefully introduced), and gut-healing nutrients (glutamine, aloe, zinc carnosine).

5. Nervous System Regulation

Chronic stress and trauma can keep the sympathetic nervous system in “high alert,” fueling mast cell activation.

Practices like vagal breathing, gentle acupuncture, EMDR, or somatic therapy help downregulate this cycle.

The Integrative Approach

MCAS management is about finding your personal balance between stabilizing the body and calming the mind.
An integrative plan may combine:

Low-dose antihistamines or cromolyn for symptom control
Quercetin and Vitamin C for natural mast cell regulation
Stress modulation through acupuncture or nervous system retraining
Gradual reintroduction of healthy, nutrient-rich foods

Key Takeaways

Mast cells are part of the body’s alarm system — MCAS means they’re too reactive.
Relief comes from reducing total “inflammatory load” through medication, diet, and stress regulation.
With individualized care, many patients regain stability and vitality.

Need Support?

We help patients uncover triggers, regulate the immune system, and rebuild resilience using a combination of naturopathic and functional medicine tools.

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If you suspect MCAS, schedule a comprehensive consultation to explore testing, nutrition, and personalized treatment options.

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