Debunking Mast Cell Activation Syndrome and Histamine Intolerance Myths

I know when I was learning about Mast Cell Activation Syndrome (MCAS) and Histamine Intolerance, there was a lot of misinformation out there. It took me a long time and a lot of research to wade through the facts and myths.

Unfortunately, many practitioners are not educated in Mast Cell Activation Syndrome and Histamine Intolerance. This has led to a kind of Wild West of Mast Cells and Histamine Information online. I see misinformation every day on websites, Facebook groups, and even from health practitioners themselves. Some practitioners even say it isn’t possible to heal from Mast Cell and Histamine issues.

I want to help you cut through some of the confusion in this post. Because believing these myths can get in the way of our healing.

I’ve personally experienced extensive healing from both Mast Cell Activation Syndrome (MCAS) and Histamine Intolerance. And I have worked with and talked to many others who have healed as well.

You can read more about the difference between Mast Cell Activation Syndrome and Histamine Intolerance here.

Myth # 1: Mast Cell Activation Disorders are Rare

When I knew I was struggling with histamine sensitivity, I turned a blind eye to reading anything about Mast Cell Activation Syndrome because I thought it was rare and surely couldn’t be something I was struggling with. Boy, was I wrong!

When I was finally diagnosed, I learned that sometimes Mast Cell Activation Syndrome (MCAS) is confused with Mastocytosis, which is a rare, but more widely known, disorder of mast cell activation with increased numbers of mast cells. Mast Cell Activation Syndrome, on the other hand, is a type of Mast Cell Activation Disorder where the mast cells exist in normal numbers, but are over-responsive.

Do you have Mast Cell Activation Syndrome? If so, it might not be that rare. Leading Mast Cell Disorder experts, Dr. Afrin and colleagues, assert that Mast Cell Activation Syndrome is much more common than previously thought. It may even be as common as 8 to 14% of the population. (1)(2)

Many people who only think they have Histamine Intolerance actually have some mast cell involvement too. And may even have Mast Cell Activation Syndrome.

Myth # 2: The Major Trigger for Mast Cell Activation Syndrome is Histamine

I used to think my main issue was histamine. I thought if I could just control histamine through my diet choices and stress reduction, then I would heal.

This worked pretty well for me for a few years, until I had a number of major mast cell triggers in a row. This included an extended trip to Seoul, Korea.

On that trip, I was working long hours. Then I returned home with the flu. I got sick two more times in five months. Finally, I was in a car accident.

My body completely crashed on me at that point. This was when I realized I needed to be aware of much more than just histamine.

I found out that while Mast Cells release histamine, they also release nearly 200 other chemicals.

Histamine foods and histamine-provoking allergens can certainly trigger mast cell activation. There are many more possible triggers, though. These can include (3)(4)(5):

  • Underlying genetic factors increasing inflammation
  • Hormone changes
  • Inflammatory foods (like glutamates, oxalates, histamines, salicylates, lectins, additives, preservatives)
  • Processed foods and additives, including carrageenan, flavorings, colorings, and preservatives
  • Stress of any kind – emotional, mental, physical
  • Alcohol
  • Fatigue
  • Some medications
  • Insect bites and stings
  • Injuries, including head injuries
  • Infections – systemic and gut-related
  • Heat or cold
  • Over-exercise
  • Chemicals, including those in perfumes, skin care products, cleaning products, and cigarette smoke
  • Friction, including from riding in a car or an airplane
  • Low oxygen levels, due to elevation, poor air quality, or airway obstructions
  • Too much sun
  • Chlorine (in shower, swimming pool, or hot tub)

Do you have trouble with any of these underlying triggers?

If so, you may need to consider Mast Cell Activation Syndrome for yourself. Be sure to find a practitioner who is an expert in Mast Cell Activation Syndrome.

Myth #3: There is Nothing We Can Do About the Genetics Underlying Mast Cell Activation Syndrome and Histamine Intolerance

This idea never rang true with me. Does it ring true for you?

Before I was diagnosed with Histamine Intolerance and Mast Cell Activation Syndrome, I already made some headway with addressing some of my genetic variants.

This greatly improved my health. After my diagnoses, I started digging into the many different genetic issues that can affect Mast Cell Activation and went on to get certified in Functional Genomic Analysis.

While the field exploring the genetic factors affecting Mast Cell Activation Syndrome (MCAS) is very new, more information is coming out each day. I’m excited to share these developments with you.

Most people who know something about the genetics of Mast Cell Activation Syndrome and Histamine Intolerance only look at the DAO, HNMT, MTHFR, and COMT genes.  But the truth is, there are way more genes involved in Histamine Intolerance and Mast Cell Activation Syndrome.

Here are just some of the genetic factors that can affect mast cell activation:

  • Genetic variants affecting histamine breakdown, including genes coding for the HNMT and DAO (ABP1 gene) enzymes. Acetylation is important too, though. Those genes include ACAT, PANK and NAT genes
  • Methylation issues – there are many, many important methylation genes – way beyond just MTHFR.
  • Variants affecting inflammation lowering antioxidants like Glutathione, SOD, and catalase
  • Glutathione recycling variants
  • Variants increasing ammonia production
  • Variants causing excess Iron and Copper to oxidize
  • Variants affecting Energy Production
  • Variants contributing to hormonal imbalances
  • Genetic variants that lower stress tolerance
  • Predisposition to gut imbalances
  • Increased sensitivity to pesticides, medications, and EMFs
  • Variants impacting digestion of fats, proteins, and carbohydrates
  • Transulfuration issues
  • Challenges with Nitric Oxide production
  • Variants affecting conversion and absorption of Vitamin A, D, and B12
  • Genetic variants affecting Glutamate Pathways and other Neurotransmitter Pathways

Sounds like a lot, doesn’t it? I didn’t even list them all. It is important to work with a practitioner who understands the complexity of these genetic variants. And particularly how they impact mast cells and histamine levels.

Myth #4: Diet Changes Can’t Help Mast Cell Activation Syndrome

If you have made any changes in your diet and felt better, you know that this one isn’t true either. When I was in college, I lived out of vending machines or on ramen noodles. That would probably kill me today!

Some people have immediate reactions to foods and can easily sort out what is causing them to react. Others take a couple days for reactions to become apparent. Those people have to follow a systematic process to figure out which foods trigger them.

I have improved dramatically through changing my diet. And I have seen many others improve as well. Any time we eat more healthfully, our bodies can heal and function better. However, what is healthy and best for one person may not be for another.

For example, spinach is considered a superfood. But it is also high in histamine and oxalates. This makes it inflammatory for those with Mast Cell Activation Syndrome and Histamine Intolerance.

Finding your personal food sensitivities and eating to support your body can make a huge difference. Of course, please work with your health care practitioner or dietitian if you plan on making major diet changes. It is essential to eat a balanced diet that includes all the necessary nutrients. Extreme diets can lead to malnutrition.

Here are some of the types of foods that can trigger mast cell activation. They may can also affect Histamine Intolerance:

  • Common food triggers: wheat, dairy, corn, soy, sugar
  • High histamine foods
  • Processed foods and food additives
  • Preservatives
  • Oxalates (for those who are sensitive)
  • Lectins – found in most grains, nightshades, grain-fed meat
  • Salicylates
  • Glutamates

Wondering what can you eat? The key is to emphasizing whole, unprocessed, nutrient dense foods chosen for your personalized needs.

Myth #5: Supplements Can’t Help much with Mast Cell Activation Syndrome and Histamine Intolerance

Fortunately for us, this isn’t true. There is an extensive amount of research on histamine lowering and mast cell stabilizing supplements.

The tricky thing is that some supplements are going to work better for some people and not work for others, depending on genetics, health issues, and labs.

Further, some supplements are contraindicated for certain conditions and genetic makeup, so supplementation recommendations are different for each person, individually.

Before I had the ability to analyze my genetics and labs, I had a lot of dead ends.

By reviewing and analyzing genetics, symptoms, and labs, I have now been able to target which supplements can work best for my body.

This process guides me in deciding which may work best for others too.

Here are a few of the best known mast cell stabilizing supplements:

  • Quercetin
    Has been shown to work as well as prescription mast cell stabilizers. It has also been shown to be very mast cell supporting, when tolerated. I find the form Alpha-Glycosyl-Isoquercitrin is the best absorbed. This means less is needed. I like to take this 30 minutes before meals. 

    Save 15% when you open a Fullscript account. 
  • Baicalin
    Also called Chinese Skullcap, is a very effective mast cell stabilizer.  Chinese Skullcap is very different from American Skullcap, so if you try this, be sure to get the kind called Chinese Skullcap or Baicalin.I’ve had really good luck with this supplement for reducing mast cell related inflammation. It can be hard to find Chinese Skullcap. I use this powdered version of Chinese Skullcap extract Baicalin.

Use Coupon Code: Mastcell10 for 10% off.

  • Luteolin 
    Is a flavonoid that has also been shown in numerous studies to help stabilize mast cells. When combined with rosmarinic acid, it can be particularly supportive. Perilla seed extract comes from a type of herb called perilla used in Korean cooking.
    Perilla seed extract has both luteolin and rosmarinic acid. It’s one of my favorite go-tos for mast cell supports.

    Save 15% when you open a Fullscript account. 

  • Holy Basil
    Also known as Tulsi, can be very effective. I use a supplement and the Tulsi Tea from Kauai Farmacy regularly and have had great results in inflammation reduction and also feeling generally more calm.

    Use code mastcell360 to save 15% with Kauai Farmacy

Holy Basil Supplement
  • Boswellia
    Is an extract of Frankincense resin. If you use Frankincense as an oil, be sure to use a pharmaceutical grade oil (such as Rocky Mountain Oils) and dilute with a carrier oil before applying to your skin.

    I’ve had good results using this as an essential oil to reduce inflammation and stabilize mast cells.

I’ve also had good results using this as a supplement to reduce inflammation and stabilize mast cells. Here is my favorite supplement. 

Boswelia Supplement
  • Vitamin C acts as a natural antihistamine, however many people with MCAS react to ascorbic acid because it is usually made from fermented corn.

    For a foods based option, I love Camu Camu* because it is low histamine and low oxalate. (I do get this through Amazon since it is dried.) I’ve found Vitamin C can help reduce my mast cell reactions, especially after accidental exposure to a trigger.

I’ve also had very good luck with the Vitamin C from Allergy Research Group. This form is magnesium ascorbate. It is a buffered, non-acidic form of vitamin C, and is not fermented or from corn. 

Save 15% when you open a Fullscript account. 

Vitamin C

If any of these supplements are new to you, try them with very low amounts first. Think sprinkles in a little water.

If you have a tendency to react to supplements, be sure to work with a Histamine and Mast Cell specialist who can help you.

Do you need help finding which supplements would be best for you? Check out my Supplements Master class called The Top 8 Mast Cell Supporting Supplements Master Class. 


  1. Afrin, Lawrence J., Butterfield, Joseph H., Raithel, Martin, Molderings, Gerard J., Ann Med. 2016; 48(3): 190–201 Often seen, rarely recognized: mast cell activation disease–a guide to diagnosis and therapeutic options.
  2. Molderings G.J., Brettner S., Homann J., Afrin L.B.. Mast cell activation disease: a concise practical guide for diagnostic workup and therapeutic options. Journal of Hematology & Oncology. 2011;4:10. doi:10.1186/1756-8722-4-10.
  3. Jennings S., Russell N., Jennings B., Slee V., Sterling L., Castells M., et al. The Mastocytosis Society survey on mast cell disorders: patient experiences and perceptions. J Allergy Clin Immunol Pract. 2014 Jan-Feb;2(1):70-6. https://www.ncbi.nlm.nih.gov/pubmed/24565772
  4. Boyden S.E., Desai A., Cruse G., Young M.L., Bolan H.C., Scott L.M., et al. Vibratory Urticaria Associated with a Missense Variant in ADGRE2. N Engl J Med. 2016 Feb 18;374(7):656-63. https://www.ncbi.nlm.nih.gov/pubmed/26841242
  5. Afrin, Lawrence, Dr. “Presentation, Diagnosis, and Management of Mast Cell Activation Syndrome.” Mast Cells: Phenotypic Features, Biological Functions and Role in Immunity. Nova Science, 2013. 155-232.
  6. Weng, Z., Zhang, B., Asadi, S., Sismanopoulos, N., Butcher, A., Fu, X., Katsarou-Katsari, A., Antoniou, C., & Theoharides, T. C. (2012). Quercetin is more effective than cromolyn in blocking human mast cell cytokine release and inhibits contact dermatitis and photosensitivity in humans. PloS one7(3), e33805. https://doi.org/10.1371/journal.pone.0033805
  7. K. (2000, April 1). Effects of luteolin, quercetin and baicalein on immunoglobulin E‐mediated mediator release from human cultured mast cells. Wiley Online Library. https://doi.org/10.1046/j.1365-2222.2000.00768.x 
  8. Prakash P, Gupta N. Therapeutic uses of Ocimum sanctum Linn (Tulsi) with a note on eugenol and its pharmacological actions: a short review. Indian J Physiol Pharmacol. 2005;49(2):125-131.
  9. Siddiqui M. Z. (2011). Boswellia serrata, a potential antiinflammatory agent: an overview. Indian journal of pharmaceutical sciences73(3), 255–261. https://pubmed.ncbi.nlm.nih.gov/22457547/
  10. Johnston, C. S., Martin, L. J., & Cai, X. (1992). Antihistamine effect of supplemental ascorbic acid and neutrophil chemotaxis. Journal of the American College of Nutrition11(2), 172–176.

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  1. Maria Custer

    I am not interested in buying supplements at this time. I have spent probably thousands of dollars on them trying to figure out what was wrong with me.
    I just want to try to focus on diet for right now. How much of skullcap powder could I add to tea? I see you say start with sprinkles but what am I maxing at? Could I do the same with Camu Camu-add to tea or drink? Thank you for any advice you can offer. I appreciate your blog!

    1. Beth O'Hara

      I know what you mean. General supplement recommendations rarely work for people with Mast Cell Activation Syndrome or Histamine Intolerance. I spent several thousand dollars on failed supplements before I learned how to target supplementation needs based on labs and genetics. This is where we get the best success. For skullcap and camu camu, it depends on the concentration you have. I would follow the package directions, and possibly experiment with a little more if you are doing well with them.

    1. Beth O'Hara

      Pycnogenol has been shown in research to have mast cell stabilizing properties. Pycnogenol is a brand name of pine bark extract. It is so effective, I used it in my MC Stabilizer formula. You can read more about pine bark extract properties in the formula sheet. Here is more info on the MC Stabilizer formula: https://mastcell360.com/supplements/

      1. Ingrid

        Hi Beth,

        I was going to order the vitamin C product recommended above, but, when looking at the description on the manufacturers website, as I wished to ask them an other question, I
        saw this stated under the vitamin c powder : «Source Materials: Ascorbic acid is derived from corn sorbitol. Sodium ascorbate is reacted from ascorbic acid and sodium bicarbonate. All ingredients are vegan and non-GMO.»

        It looks like the ascorbic acid in the powder is derived from corn after all. What do you think about this, and what vitamin c supplement would you then recommend for someone sensitive, and with a sensitive gut? Hoping to get your opinion about this, as I am finding it somewhat difficult to know which vitamin c to try out. I am very low in vitamin c.

        Secondly – I did read one of your other blog articles, and saw you mentioned coq10. Do you have a coq10 supplement for people low in this, to recommend not made through fermention? Or, do you find it Ok with the fermentation process in this regard?

        Thank you!
        Kindly, Ingrid

      2. Kelly

        Unfortunately pycnogenol can be too astringent for some people, resulting in constipation and joint pain, among other thingsl

        1. Beth O'Hara

          Hi Kelly,
          I haven’t seen constipation with pycnogenol, but you are right, some people do react to it. With Mast Cell Activation, anything can be a trigger. Even very simple things. There isn’t a single supplement in my practice that everyone can tolerate. This is why it is critical to work with a health care practitioner and try new things very carefully.

  2. sherry

    I have just started taking chinese skullcap and camu camu and having really good results in just the past 3 days. However, I am reading on the internet that it can cause liver damage with other herbs. I do take other herbs. If I space them out, say 2 to 4 hours apart will that prevent liver damage? Or do you know if is it an issue even if you do that?

  3. Lené

    When I followed the link to the vitamin C you recommend, it says, “Ascorbyl palmitate is derived from corn dextrose fermentation and palm oil.” My impression from your post, though, is that this should offer a corn-free alternative for those who react. Did I misunderstand, or is there another product we should consider instead? Thanks.

    1. Beth O'Hara

      Thanks for bringing this to my attention! It used to be made from tapioca. I added a different Vitamin C option above. Beth

  4. Peggy Pysher

    I can’t even find a health care practitioner who can help me and diagnose if I have more than a histamine intolerance. A physician agreed to have my histamine level tested, which was high off the range, but he said there is not much known about it, and just gave me scripts for antihistamines and an epi pen. I search online myself and find people like you, spend more money than I have on supplements recommended, all trial and error. Dietary changes have helped some, and taking DAO enzyme has helped the most. How do I go about getting testing for more than the histamine? For mast cell, etc. ? Thank you.

  5. Nichole

    Just an FYI as I looked into a tapioca based Vitamin C (as ascorbic acid) for my MCAS daughter. I called the manufacturer and they confirmed it was derived by a fermented process. No corn, but fermentation, so it would be high in histamine and a no go for her unless we wanted to risk a reaction. We avoid fermented products or bi-products at all costs.
    Thank you for all your information and helping the MCAS community!

    1. Beth O'Hara

      Thanks so much, Nichole! Which brand was it? That info could really help a lot of people. Looking forward to hearing back from you.

  6. Sue Ann Walker

    Hi Beth. I notice you don’t mention tyramine intolerance as many of the issues MCAS folks can have as I know I have that and I think there are so many with migraine symptoms that also have never tried the low tyramine low histamine elimination diet to see if they improve without Tyramine triggers. I hope you bring this to light some and I am interested in working with you in the near future on my health issues ! thank you for this great blog!

    1. Beth O'Hara

      Hi Sue Ann. Thanks so much for reading! I’m really glad you enjoy the blog. The low histamine diet on the website is also low tyramine. Histamine is a type of tyramine, and a low histamine diet includes tyramine triggers as well as other types of histamine triggers and liberators. Hope that helps!

  7. Jill

    I appreciate the information you put out there but I have to be honest …this will terrifies me! I don’t even know if I actually have MCAS but reading about all these triggers and problems. Yikes. Very overwhelming!

  8. Cindy

    Hi Beth,

    Just wondering which of the supplements you mentioned above are suitable for fertility / if you are trying to fall pregnant? I have read that Holy Basil for example should be avoided. Are there supplements that are suitable for fertility whilst working on Histamine/Mast Cell stabilising? If you don mind listing them that would be very helpful. I also need something that will regulate my irregular menstrual cycle if possible. I’m currently taking Vitex and was thinking of trying Shatavari (i’m not sure if Shatavari helps with histamine or not). If there is nothing else that regulates the cycles it would be great to at least know which of the Mast Cell stabilsing herbs are also safe for Fertility. Thankyou for such a wonderful blog and website 🙂

    1. Suz, Mast Cell 360 Team

      Hi Cindy,
      I’m so glad to hear the website is helpful for you!
      These are great questions! If you send us a message, we can connect you with someone who can help you with this.

  9. Judy Rule

    Do you have any recommendations for Moringa Tea? Safety, etc?

    1. Suz, Mast Cell 360 Team

      Hi Judy
      Moringa is often recommended as an anti-inflammatory superfood, but as healthy as moringa is, it’s not necessarily good for people with Mast Cell Activation Syndrome or Histamine Intolerance.
      The reason for this is that moringa is high in oxalates. And oxalates can raise histamine levels.
      You can read more about this and what to use instead here:

  10. Sara

    I just want you to know that your blog has helped me more than any practitioner I have had! I am working with a ND for mold toxicity but the level of detail you provide has been invaluable. I have taken your supplement class and highly recommend it to others. It turns out I have been dealing with Mast cell activation for over 10 years! I am finally clear of the mold but now have to figure out how to treat the mast cell stuff. Thank you so much for all of your detailed work on this blog! I would love to see you as a patient once you open up your practice to new patients. Got my fingers crossed as I am sure you are busy!

    1. Suz, Mast Cell 360 Team

      Hi Sara,
      Thank you so much for reaching out. I am glad to hear you are finally clear of mold!

  11. Neha

    Hi Both, are any of these safe for slow COMT gene? I find sometimes Vitamin C and Quercetin increase my anxiety/cause shortness of breath. Are there any natural anti-histamines that are safe to use in such cases?

    1. Suz, Mast Cell 360 Team

      Hi Neha,
      I don’t know if these will work for you since I don’t know your history, but these are usually better tolerated for over-methylators. Please be sure to talk with your practitioner with questions or concerns. If you decide these are right for you, start slowly and gradually build up. If you use the links below to set up a FullScript Account, you can get 15% off the FullScript orders. (does not apply to the DAO from Mast Cell 360 shop.)

      BiCarb formula

      All Qlear



  12. Dee

    Hi Beth, thank you for a very interesting and informative article.

    My partner and I are hoping to start trying to conceive soon. I am currently wrangling with mast cell activation symptoms and was wondering if you know which of the above herbs are suitable to be on from a fertility perspective? I am also taking a combo of milk thistle, vitex, passionflower and shatavari, in the hopes of helping to regulate my cycle and for conceiving, although I’m not sure of their effect from a mast cell activation perspective? (hopefully positive!) Would you have any information on whether the above herbs you discussed are okay from a fertility perspective? And if the ones I’m using for fertility are okay from a mast cell activation perspective? If you have any information you could share at all or point me towards I’d be extremely grateful. Thank you as always for such fantastic and groundbreaking knowledge- I would be lost without this blog! Warmest regards and happy new year to your team. Dee

    1. Suz, Mast Cell 360 Team

      Hi Dee,
      Thanks for reaching out to us. This is more than we can help guide you with online, but we are onboarding a fertility coach.

  13. Philippa White

    All the sodium ascorbate that I can find is derived from corn; even worse grown on aspergillus mould. I would also add mould and flouride to your brilliantly comprehensive list.

    I think your website is great.

  14. Bob

    Hi Beth
    The Chinese Skullcap extract Baicalin mentioned above by Liftmode contains Ascorbyl palmitate (Vitamin C) which you’ve mentioned in articles to avoid. Is there another brand you recommend?

    Great website.

    1. Suz, Mast Cell 360 Team

      Hi Bob!
      I’ve just double checked the listed ingredients for the Baicalin powder which you can find here: https://affiliate.liftmode.com/idevaffiliate.php?id=119&url=192
      The powder doesn’t have ascorbyl palmitate. It may be possible that you got a link for the capsule instead. I will check our post here to make sure it is linking correctly. Thanks for reaching out!

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