Is it MCAS or is it All in Your Head? Compounded Medications to the Rescue.

Author: Bryana Gregory, PharmD, RPh, Physician Liaison

Is it MCAS or is it All in Your Head? Compounded Medications to the Rescue.

“I’m allergic to everything!”
“I feel awful in general!”
“My doctor says it’s all in my head.”
“I have hives, but I have no idea why.”
“I have period migraines.”

Do any of these complaints sound familiar to you?

If so, you need to learn about Mast Cell Activation Syndrome (MCAS), a complex, increasingly common and often undiagnosed collection of symptoms. It is estimated that roughly 17% of the population and 35% of obese patients suffer from MCAS.

Symptoms of MCAS usually appear in childhood but extend well into adulthood, unfortunately remaining undiagnosed in most patients. These symptoms, which often wax and wane, can affect multiple areas of the body. In fact, no system is immune to MCAS, including the immune system.

Patients with MCAS tend to be sensitive to foods, supplements, and/or medications. They are the “canaries in the coal mine,” the first to detect mold in a building, the first to react to environmental allergens and pollutants, and the first to break out in hives. They often claim to “feel awful in general,” even though their lab tests and scans frequently show them to be the “absolute picture of health.” This leads to confusion and frustration for patients and providers alike.

MCAS may be the most highly complex multisystem condition we are facing today, yet most healthcare professionals have not been trained to recognize, diagnose, or even treat it effectively. When doctors are unfamiliar with MCAS, they may label very real symptoms as “imaginary” or “all in your head.”

What Are Mast Cells?

To begin peeling back the layers of MCAS, we must first understand what mast cells are and how they function. Mast cells are a type of innate immune white blood cell present in nearly every tissue in the body. Abundant in the organs which function as a first line of defense, including the GI tract, skin, lungs, and nose, mast cells play an important role in mounting appropriate allergic reactions, protecting us from infection, and maintaining blood-brain barrier function. They are also found in the eyes, ears, lymphatic vessels, nervous system, and bones, which explains the diversity of problems linked with MCAS.

There are over 200 different types of mast cell receptors, including histamine, cytokine, toll-like, corticotropin releasing factor, and hormone receptors, to name a few. When mast cells are overresponsive to triggers, all other systems fall in line with haywire overactivation. The mast cell’s primary goal is to keep the body safe, and when any threat is posed to the body, mast cells react.

Mast cells are necessary for appropriate immune responses, but when chronically overactivated, every system in the body goes haywire. This is the essence of MCAS.

What Activates Mast Cells?

  • Everything we breathe
  • Everything we swallow
  • Everything that touches our skin
  • Neurotransmitters
  • Stress and stressors
  • Hormones
  • Injuries/trauma
  • Medications and supplements
  • Invisible energy and vibrations (i.e., EMF, Wifi)
  • Pathogens

7 Common Root Causes of MCAS

  1. Food triggers
  2. Hormone imbalances
  3. Infections and toxicity
  4. Stress and/or early trauma
  5. Genetic factors
  6. Hypoxia (oxygen deficiency in the tissues)
  7. Nutritional deficiencies

What Are Common Symptoms of MCAS?

One reason MCAS is difficult to pin down is because it affects so many organs and tissues in the body. Symptoms often show up in areas of first-line defense, where mast cells are particularly dense. Some of the most common symptoms include:

  • Temperature abnormalities, cold most of the time or low-grade fever
  • Fatigue/malaise, unable to get out of bed, often waxes/wanes
  • Unprovoked sweats, most often at night and especially on the back
  • Hot flashes
  • Impaired healing ability
  • Decreased appetite and early satiety
  • Brain fog
  • Fluctuations in blood pressure
  • Dizziness leading to loss of consciousness
  • Dramatic and abrupt weight losses/gains
  • Itchy skin affecting different areas

Unfortunately, this list barely scratches the surface. MCAS related problems also include a variety of skin problems, vision and hearing disorders, environmental allergies, respiratory conditions, frequent infections, lymph node enlargement, hematologic (blood) disorders, weakness, anxiety, depression, insomnia, and more.

There is also a strong link between MCAS and histamine intolerance, which may result in unexplained hives or congestion, migraines, heart racing following meals, insomnia, and panic attacks. Histamine is regularly released from mast cells to participate in the inflammatory process, blood vessel dilation, digestion, and as a chemical messenger to the brain. Conditions perpetuating histamine intolerance include gluten sensitivity, estrogen dominance, leaky gut, gut infections, IBD, mold sensitivity/ exposure, and EMF sensitivity. However, MCAS is the number one driver of histamine intolerance.

How Is MCAS Treated?

The goal in the treatment of MCAS is the elimination of triggers, calming of mast cells and symptom resolution. Supporting the immune system, gentle detoxification, hormone balance and combating biotoxin illness are equally important.

Treatment includes lifestyle changes, starting with identifying individual triggers such as foods, stressors, mold, infections, etc. For example, if histamine sensitivity is an issue, as it often is, it is important to avoid high histamine foods and beverages like red wine, avocados, spinach, pickled foods, leftovers, and foods cooked in a Crockpot.

Targeted medications are also useful in the treatment of MCAS. They include compounds to help stabilize mast cells, suppress the adverse effects of excessive histamine, support detoxification pathways, reduce inflammation, balance hormones, and relieve symptoms.

Because allergies and sensitivities are common in patients with this condition, it is important to use medications that are free of bothersome inactive ingredients such as dyes, artificial colors and flavors, and additives. Physicians Preference Pharmacy offers a number of compounded medications that have proven helpful for our MCAS patients.

New Compound to Help Treat MCAS: Cromolyn Sodium

Cromolyn Sodium functions as a mast cell stabilizer and helps to calm the mast cell reaction and allergic reactions. It prevents the subsequent release of inflammatory mediators, including histamine and leukotrienes, which cause allergic symptoms and bronchoconstriction.

Cromolyn Sodium inhibits mast cell degranulation, normally implicated in anaphylaxis following exposure to reactive allergens. It inhibits immediate and late reactions.

The use of Cromolyn Sodium has been associated with improvement in flushing, headaches, diarrhea, vomiting, nausea, urticaria, abdominal pain, and itching in patients with mastocytosis.

Our Compounded Antihistamines

At Physicians Preference Pharmacy, we also compound antihistamines, that when used alone or in combination with allergy treatments, are highly effective against the effects of MCAS. Our compounded medications are always free of unnecessary dyes, binders or fillers, and our compounds contain the active ingredient and only the necessary filler for accurate and consistent dosing – hypromellose and/or microcrystalline cellulose.

The compounded antihistamines we offer include:

  • Famotidine capsules
  • Loratadine capsules
  • Diphenhydramine slow-release capsules
  • Brompheniramine slow-release capsules
  • Chlorpheniramine slow-release capsules
  • Hydroxyzine capsules
  • Ketotifen capsules

Hope for MCAS

Patients with MCAS must understand that mast cells are not the bad guys, but these cells must be tamed to function normally. With appropriate lifestyle changes, an intentional treatment regimen, and encouragement for healing, symptoms of MCAS are expected to improve over time. At Physicians Preference Pharmacy, we are here to support you and your healthcare providers by providing pure compounded medications and information about MCAS. Call our pharmacy at 281-828-9088 to speak with any pharmacist about MCAS today!

We Are Here to Help

Our compounded medications for MCAS do require a prescription from your provider. Please call our pharmacists today with any questions about compounded antihistamines and Cromolyn Sodium for MCAS or about your compounded prescription needs at 281-828-9088. It will be our privilege to serve you!


Afrin, Lawrence B. Never Bet Against Occam. Createspace Independent Pu, 2016. Dr. Charles Crist, American Academy of Environmental Medicine, Spring 2021

Katrina Minutello; Vikas Gupta, Cromolyn Sodium, National Center for Biotechnology Information, January 2, 2023.