Beth holding diamine oxidase

Diamine Oxidase (DAO) for Mast Cell Activation Syndrome or Histamine Intolerance

Do you suspect you have Histamine Intolerance? Could diamine oxidase (DAO enzyme) help? 

Are you suffering from bloating, reflux, flushing, headaches, or itching a couple hours after eating? 

If so, you’re like my client, “Rosa”. 

She had those symptoms, and her itching was worse at night. 

And she often woke up around 3am and had trouble falling back asleep.  

That was a clue she was dealing with Histamine Intolerance. 

Did you know your body has a huge “histamine dump” between about 2-4 am? 

So, I recommended she try a supplement called diamine oxidase (DAO enzyme)

It helps break down histamine in your gut. 

She said she’d tried it before, and it didn’t help.  

I’d had success using DAO supplements myself. Many Mast Cell 360 clients did, too. 

So, I asked how frequently she had taken it and how much. She’d taken 1 capsule 2x/ day. 

See, when it comes to diamine oxidase, some people need more than others.  

Rosa was willing to try again.  

We increased the amount little by little until her symptoms improved.  

She started sleeping better. The itching, headaches, flushing, and bloating eased, too. 

Diamine oxidase isn’t a cure-all for Histamine Intolerance or MCAS. Like Rosa, you’ll still need to work on underlying issues. 

But the DAO supplement can give you symptom relief. 

Want to know more about diamine oxidase? Keep reading to learn:  

  • Histamine Intolerance and diamine oxidase 
  • What is diamine oxidase? 
  • What causes low diamine oxidase? 
  • How DAO supplements help HIT and MCAS 
  • Why diamine oxidase might not have worked in the past 
  • The best DAO supplement for Histamine Intolerance 
  • DAO supplements vs. taking kidney supplements  
  • Who should and shouldn’t consider DAO supplements 

Let’s start with a quick overview of histamine and Histamine Intolerance.  

It’s important you know that this blog post is for informational and educational purposes. It’s not meant to treat any health condition or to be prescriptive for anyone.  If you have any medical condition, it is critical you work under the care and guidance of a licensed medical provider. 

Diamine Oxidase and Histamine Intolerance

Knowing more about histamine and Histamine Intolerance will help you know why diamine oxidase (DAO enzyme) is important.  

Your body naturally makes histamine.  

Histamine gets released from your cells as part of cell signaling. 

Cell signaling is another way of saying that your cells communicate with the rest of your body. These chemicals send important messages throughout your body about how to function. 

You may also hear these chemicals referred to as mediators. 

Histamine is just one of many mediators. 

It plays big roles in your body’s immune system, nervous system, and even digestive system. 

Histamine is also found in some of the foods you eat. 

To learn more about low and high histamine foods, check out the Mast Cell 360 Low Histamine Foods List. 

Together, the histamine your body makes and the histamine in the foods you eat add to what’s called your histamine load. This is the amount of histamine your body has at any given time. 

Normally, histamine gets broken down by different enzymes. 

But if your detox pathways are dysregulated, you might not be producing enough of these histamine-degrading enzymes. 

(Hint: Diamine oxidase is one of those histamine-degrading enzymes.) 

So, the histamine keeps building up.  

And even though histamine plays important and necessary roles in your body, too much histamine can be a bad thing. 

That’s because it creates inflammation and triggers the mast cells. 

At some point, it can become more than you can handle. 

Histamine Intolerance is when your body can’t break down histamine as fast as it’s coming in.   

Related Article: What is Histamine Intolerance? 

If you have Mast Cell Activation Syndrome, you might also have Histamine Intolerance. This isn’t always the case. But here’s why the two can be linked. 

Histamine Intolerance and Mast Cell Activation Syndrome 

Your mast cells are part of your immune system. Mast Cells have receptors that respond to everything.  

They respond to things in your body as well as external things like temperature, for example. 

They are your first line of defense against pathogens like viruses and bacteria. 

Part of the mast cell response is to release those chemical mediators you just read about. Including histamine.  

If you have Mast Cell Activation Syndrome, your mast cells are overly responsive. We sometimes refer to this as having haywire mast cells

That means those receptors get all messed up. The cell signaling becomes dysregulated.  

When this happens, mast cells respond to things they should (bacteria, etc.), AND they can respond to things they shouldn’t (like certain foods, for example). 

It can also mean they just don’t know when to stop releasing the mast cell mediators like histamine.  

See, normally, once a threat has been dealt with, your body will see this as a job completed. And it will quit releasing these mediators. 

But with haywire mast cells, this doesn’t always happen. 

What it comes down to is that if your mast cells are responding, they are releasing histamine.  

And in Histamine Intolerance, histamine isn’t getting broken down quickly enough. This excess histamine can continue to trigger the mast cells through their histamine receptors.  

That’s why getting your histamine under control can help with MCAS. 

Next, look at some of the more common symptoms related to Histamine Intolerance next.  

Can DAO Support Symptoms of Histamine Intolerance? 

One of the main ways you can experience Histamine Intolerance is as a food intolerance. 

You begin to have reactions to foods, especially high histamine foods. 

Your body is telling you it can’t take anymore. 

That’s why a low histamine diet can help with Histamine Intolerance. 

This list isn’t all the symptoms related to Histamine Intolerance. But it gives you an overview of the more common ones.  

Do you have problems with any of the following?  

You may want to explore Histamine Intolerance further if you and your provider have ruled out other conditions. 

  • Abdominal pain 
  • Acid reflux  
  • Anxiety   
  • Asthma 
  • Bloating  
  • Brain fog 
  • Congestion   
  • Diarrhea 
  • Eczema  
  • Flushing 
  • Gas   
  • Headaches   
  • Hives / Urticaria 
  • Insomnia  
  • Itching 
  • Rashes  
  • Runny nose 
  • Sneezing  

Again, these are just a few symptoms to consider.  

And these symptoms can be related to other conditions, too. So always be sure to talk with your provider about any new or worsening symptoms.  

Now you know a little about Histamine Intolerance. Let’s get back to how diamine oxidase (DAO enzyme) plays a role in that. 

I hinted earlier that diamine oxidase was one of the enzymes that your body makes to break down histamine. 

If you aren’t making enough diamine oxidase to keep up with your histamine load, that’s one way you can end up with Histamine Intolerance. 

Keep reading to learn more about what diamine oxidase (DAO) is and why you might have a DAO deficiency? 

What is Diamine Oxidase (DAO)?  

It’s important you know that this blog post is for informational and educational purposes. It’s not meant to treat any health condition or to be prescriptive for anyone.  If you have any medical condition, it is critical you work under the care and guidance of a licensed medical provider.  

Diamine Oxidase (DAO) is a major histamine-degrading enzyme in your gut.  

It’s naturally made in your body. It’s one of several enzymes that is used in histamine degradation.  

There are other histamine-degrading enzymes, too, such as: 

  • HNMT (histamine N-methyltransferase)  
  • ALDH (aldehyde dehydrogenase)  
  • MAO (monoamine oxidase)  
  • UGT1A4 (UDP-glucuronosyltransferase 1-4)  
  • ACAT (acetyl-CoA acetyltransferase)   
  • NAT (N-acetyltransferase) 
  • CYP1A2 (cytochrome p450 family 1 subfamily A member 2) 

You’ll be reading more about diamine oxidase next. But I just wanted to mention the others to give you some background.  

Here’s what should happen with histamine. 

Without getting too involved, basically your body should break down histamine into other compounds like imidazole acetaldehyde.  

Ultimately, histamine should get processed to a point where the compounds get eliminated from your body by way of your kidneys. 

Diamine oxidase (DAO) plays a big part in this process of breaking down histamine. 

If you don’t have enough diamine oxidase, you probably aren’t breaking down and eliminating histamine. That’s where problems can occur.  

Having low DAO activity can be a major factor in Histamine Intolerance and Mast Cell Activation.  

Some factors that can contribute to low DAO activity are: 

  • Genetic variants 
  • Gut inflammation or dysbiosis  
  • Mold Toxicity
  • Nutrient Deficiency 

Let’s briefly look at these factors next. 

What Causes Diamine Oxidase (DAO) Deficiency? 

This list is by no means complete. But here’s a little more on a few of the top factors that may be contributing to your low DAO activity. 

Genetics and DAO Deficiency 

If you get genetic testing, you can look for variations in the AOC1(amine oxidase, copper-containing, 1) / ABP1 (Amiloride binding protein 1) gene. This may help you determine if you are genetically more prone to DAO deficiency. 

However, genetic expression is more important than genetic makeup. 

Your genetic makeup is the information encoded in your genes. 

According to National Human Genome Institute, “Gene expression is the process the cell uses to produce the molecule it needs by reading the genetic code written in the DNA.” 

But the process of gene expression can change substantially under different conditions. 

Bottom line: there’s a lot you still have control over. You aren’t doomed from birth. 

You’ll read more about how you can support your diamine oxidase activity coming up. 

Next, look at another big factor that can lead to low diamine oxidase activity. 

Gut Inflammation Impact Diamine Oxidase 

Diamine Oxidase (DAO) is made in the gastrointestinal tract…the small intestine to be specific. 

Inflammation of the GI tract can interfere with your ability to make diamine oxidase. 

Studies have shown that IBS, Crohn’s, Celiac and other inflammatory bowel diseases can affect DAO activity. 

Gut dysbiosis can also contribute to low DAO activity. Gut dysbiosis is what happens when the gut flora gets out of balance. 

That can happen with conditions like SIBO (small intestinal bacterial overgrowth) and SIFO (small intestinal fungal overgrowth). 

Even Mast Cell Activation Syndrome can contribute to inflammation of the digestive tract.  

So can conditions related to food allergies, food intolerances (like Lectin Intolerance) and food sensitivities (like Gluten Sensitivity). 

And did you know that histamine can break through the GI mucosal lining? When it breaks through this intestinal mucosa, it can enter the bloodstream. 

That can increase inflammation even further. And further trigger mast cells. 

Additionally, gut inflammation can interfere with your body’s ability to absorb nutrients. 

That can lead to nutritional deficiencies. That’s what you’ll read about next.  

Nutritional Deficiencies Effect Diamine Oxidase 

A nutrient deficiency is when you lack certain vitamins and minerals.  

And since you need nutrients are needed to produce diamine oxidase, a nutrient deficiency can impair your ability to make the DAO enzyme. 

And nutrients are also needed to activate DAO.  

That means that nutrients are necessary to make the DAO enzyme AND to make these enzymes work once they are made. 

Here are some of the nutrients that can support diamine oxidase (DAO) levels: 

If you have nutrient deficiencies, you may need to supplement some of these other vitamins and minerals in order to help support yourself. 

A note about supplementing copper. You’ll see I didn’t provide a link to copper as a supplement above.  

Copper supplementation may work well for people who don’t have Mast Cell Activation syndrome and who aren’t sensitive. 

But I’ve seen copper supplementation backfire for those who do have MCAS and sensitivities. 

This has to do with the importance of the ratio of copper to zinc. Too much copper can cause a zinc deficiency. 

And we’ve rarely seen someone with too little copper in relationship to zinc in the population we work with in the practice. 

So, it’s usually better to balance zinc first and check copper/zinc ratios before supplementing with copper. 

That’s why in the Mast Cell 360 practice, we tend to hold off on copper. 

Mold Toxins Impact Diamine Oxidase

Mycotoxins are toxins from mold. And they are bad news.  

Mold toxins can: 

  • Dysregulate your immune and nervous systems  
  • Create or add to gut issues, including gut inflammation 
  • Mess up your detox pathways  
  • Negatively impact genetic expression  
  • Lead to nutrient deficiency  

This list includes a lot of the things you just read about that can contribute to low diamine oxidase activity. 

So, to sum up, you can support diamine oxidase activity by: 

  • Supporting good gut health 
  • Getting good nutrient support through diet and supplements 
  • Working on addressing mold toxicity 

There’s also one straightforward way to support diamine oxidase activity. 

And that’s by taking a DAO enzyme supplement.

But there are a few things you should know to choose the best DAO supplement for your needs. 

Keep reading to learn more about: 

  • What to avoid in a DAO supplement 
  • What to look for 
  • Who should and shouldn’t consider DAO supplementation 

First, look at why DAO supplements may not have worked for you in the past.  

Diamine Oxidase Supplementation: The Bad and The Good 

Remember when you read about my client, Rosa? She had tried a DAO supplement before, and it didn’t work for her.  

In Rosa’s case, she wasn’t taking the amount she needed to support her level of Histamine Intolerance. Once we got that adjusted, she got relief from her symptoms. 

There are a few other reasons DAO supplements might not have worked for you, too, though. 

Why DAO Supplements May Not Have Worked 

For some people nutrient deficiencies may have kept DAO supplements from working. You just read how nutrient deficiencies can inhibit DAO activity. 

If you had nutrient deficiencies when you took DAO, it may have been that you didn’t have enough nutrients to support DAO levels.. 

So even if you are taking a DAO enzyme supplement, you may not have had the nutrients needed that DAO depends on. Like B6, for example. 

And other people, especially those with Mast Cell Activation Syndrome, have had reactions to DAO supplements in the past likely due to filler ingredients. 

We’ve found many people in our community are sensitive to ingredients found in some DAO supplements such as:  

  • Ascorbyl palmitate (Vitamin C derived from fermentation making it higher histamine) 
  • Catalase  
  • Corn starch (learn about corn and MCAS here) 
  • Talc 
  • Titanium dioxide 

But here’s why you may want to consider DAO enzymes again. 

I’ve developed a new custom DAO supplement for those with MCAS, Mold Toxicity, and sensitivities!   

Diamine Oxidase: A Game-Changer for Histamine Intolerance 

When I was in my 20’s, I was fermenting veggies and making kombucha and kefir. 

I ate a lot of seafood, spinach, and mushrooms.  

And I loved pineapple and strawberries.  

It was a histamine nightmare. But I didn’t know better. What I did know is that my sleep kept worsening. 

And I was itching all the time. 

I had constant post-nasal drip. 

I had diarrhea several times a day. 

My acid reflux was off the charts. 

And I had terrible fatigue.  

My health was a mess. And I didn’t know what to do.  

But I wanted to feel better.  

So, I started paring down foods. I figured out that I felt sick when I ate my go-to foods like strawberries, spinach, and seafood. 

I started to avoid those…and any other food I had a reaction to. 

It felt like I was paring foods down more and more. At one point, I was down to 10 foods. I had one protein source, a few vegetables, and some herbs. 

One day, I came across an article about diamine oxidase (DAO enzyme) by Yasmina Ykelenstam. She was one of my early teachers in this area. 
So, I thought I should give it a try. 

It turned out to be a game changer! 

The DAO supplements eased my symptoms. And they allowed me to eat more foods. That meant I was getting a wider variety of nutrients to support my health. 

It was one of the first big steps I took toward getting my health back. 

The Only Problem Was… 

So, when I started the Mast Cell 360 practice, I recommended DAO enzymes to many of my clients with Histamine Intolerance. 

I hoped it would help them, as it helped me. But I eased up on recommending it. And I didn’t write about it on my blog either. 

That’s because I saw that some people were reacting to the formulas available at that time. 

In the first formula, the “dirty” fillers were causing problems. In the second formula, some people were still struggling with the form of vitamin C (the ascorbyl palmitate.)  

I was able to use it myself. But I was still seeing more reactions to it than I liked seeing.  

But even though it probably caused some inflammation, it also helped me get back more foods in my diet. 

So, I knew that DAO could make a huge difference for people with Histamine Intolerance and Mast Cell Activation Syndrome. 

But there just wasn’t anything else on the market I found that would be any better tolerated. 

And because some people were having reactions, that kept me from recommending it more. 

Then I got to thinking, “What if I formulated a DAO supplement for this sensitive population?”  

I did some investigating. I’m happy to tell you that I was able to work with Diem, the sole manufacturer of all DAO in North America, to get a custom formula made.  

Histamine Digest 360 Diamine Oxidase (DAO) 

My custom formula created especially for people with MCAS and HIT is now available! 

I formulated this DAO (diamine oxidase) supplement, called Histamine Digest 360, especially for people with food restrictions and sensitivities. 

If you’ve tried a DAO supplement before and reacted, you may tolerate Histamine Digest 360 better. 

It’s a very clean, simple formula for sensitive people. 

I’m so excited about it!  

This new formula does not contain: 

  • Wheat 
  • Gluten 
  • Yeast  
  • Soy 
  • Dairy products 
  • Fish 
  • Shellfish 
  • Peanuts 
  • Tree nuts 
  • Egg 
  • Ingredients derived from genetically modified organisms (GMOs) 
  • Artificial colors 
  • Artificial sweeteners 
  • Artificial preservatives  

Here’s what the new formula does have.  

Active ingredients:  

  • Vitamin B6 (from Pyridoxal-5-Phosphate)  
  • DAO2™ (Porcine Kidney) extract  

Other ingredients:  

  • Microcrystalline cellulose (Avicel® PH-112)  
  • DR Capsule® Size “1” Vegetable (Hypromellose, Gellan Gum)  
  • L-Leucine (Vegan)   

That’s it.  

The hypromellose and gellan gum are the capsule ingredients. These aren’t normally an issue for most people. 

But if you aren’t sure, you could open the capsule and put the contents in water.  

And you’ll notice it has a tiny fairy dust amount (1mg) of B6. B6 is one of the nutrients needed to activate the DAO and make it work. 

This is important for people with food restrictions or Mold Toxicity who may be low in B6. 

This is a much cleaner formula. I’m taking it myself.  

And I’ve trialed it with sensitive clients who are seeing good results, too.  

 So, keep reading to see if you should be taking DAO supplements.  

How To Know If You Should Use Diamine Oxidase  

If you have any of the following, you may want to consider DAO supplementation:  

For the vast majority of people with Mast Cell Activation Syndrome or Histamine Intolerance, DAO supplementation is very helpful.  

It can be especially helpful for:  

  • GI Symptoms  
  • Acid Reflux  
  • Flushing  
  • Itching  
  • Runny Nose  
  • Allergy Type Symptoms  
  • Breathing Trouble 

If you are still eating higher histamine foods, diamine oxidase (DAO) won’t be able to take care of all the excess histamine, though.  

But it can certainly take the edge off.  

And even if you are eating low histamine foods, you may want to consider DAO enzymes, too. 

Did you know that just the act of digesting creates histamine in the gut? This is true even if you are eating low histamine foods. Histamine plays an important role in digestion. 

If you have Histamine Intolerance, you want to factor in all the ways you can support histamine degradation. 

How Long Before You See Results from Diamine Oxidase? 

Everyone is different. There isn’t one set amount of time that you can expect to see changes. 

Some people may not notice a difference for a few weeks. That’s because they must get their overall histamine load down. 

But often, after just a few weeks of using Histamine Digest 360, your gut histamine levels should be lower. And then you may find your food tolerance will increase!  

And like my client, “Rosa” you need to get to your target dose. That’s when Rosa saw most of her improvements.  

Don’t give up on the DAO supplement if you don’t notice immediate change. Give yourself some time.

And be sure to work with your provider to find what your target dose should be. 

How to Get the New, Clean DAO Formula + Free Shipping  

Histamine Digest 360 is in stock! 

If you haven’t tried diamine oxidase (DAO) before, you’ll probably want to start with the 60-capsule bottle. Especially if you are only tolerating a few supplements right now. That way you can try it out.  

>>>>>You can get the new DAO here (US and Canada)

Make sure you’re getting my custom formula, Histamine Digest 360 with the pink label. It’s a clear capsule with white powder. 

Histamine Digest 360 Diamine Oxidase by Diem

In other formulas on the market, you may see little round pellets inside the capsule. That’s not the one you want.  

Those other formulas may have some ingredients that aren’t ideal if you have sensitivities.

I’ve been seeing that the Histamine Digest 360 has been better tolerated. 

How I Use Diamine Oxidase Enzymes 

You may want to consider using this daily if you have Mast Cell Activation or Histamine Intolerance 

I find that DAO enzymes work best when taken about 10-15 minutes before a meal. That’s ideal.  

If you forget, just try to take it before you start eating. 

But, I’ve even taken it at the end of the meal when I’ve forgotten to take it before. This will also help. 

But the optimal benefits are when you take it about 10-15 minutes before you start eating.  

Tips for Taking DAO Enzymes

Here are some general guidelines I’ve learned work well for taking diamine oxidase (DAO). 

  • For low histamine meals, I take 3 capsules before eating.  
  • If my gut is really inflamed, I take 4-5 capsules before eating.  
  • When I’m eating at restaurants, I take 5-6 capsules before eating.  
  • On special occasions if I’m having a high histamine food, I’ve taken 6-8 capsules or more. 

And anytime you onboard a new supplement, go slowly. Start with drops or sprinkles if you aren’t sure if you’ll tolerate a supplement.  

Some people have asked, “What happens if I take too many?” 

DAO is something your body naturally produces. If you take more than you need, it isn’t normally harmful.  

I’ve seen people get some mild heartburn or loose stools if they take really high amounts. 

But generally, DAO is very safe to take. And it can be used long-term.  

However, you should still talk with your provider about any questions or concerns. 

DAO can be a game-changer for many people with Histamine Intolerance. But there are some less-common reasons that DAO may not be right for you.  

Keep reading to see if you fall into these categories. 

Who Shouldn’t Try DAO Enzymes? 

We want to consider many of the sensitivities that our community may have.  

In some cases, these sensitivities are temporary, so you may be able to try a DAO supplement at a later point. 

But it’s still best to know even the less common reasons you may need to avoid DAO. 

Not Tolerating Any Supplements? 

If you aren’t tolerating any supplements at all, even a clean formula of DAO enzymes might not be where you want to start. 

Some people are in a state where they react to all supplements. This is usually due to significant limbic and vagal dysregulation. 

In this case, you may want to consider working on your nervous system first. 

You can read more about why that’s such an important part of the MC360™ Method and why it can help with tolerating supplements. 

Related Article: Nervous System Balance is Essential in Mast Cell Activation Syndrome and Histamine Intolerance  

Once you get your nervous system calmed down, you may be able to tolerate more supplements. You can talk with your provider about the right time to onboard DAO then. 

Alpha-gal Syndrome 

Another reason you may need to avoid diamine oxidase (DAO) is if you’ve been diagnosed with Alpha-gal Syndrome. With Alpha-gal Syndrome, you must avoid mammal products. 

Alpha-gal is fairly rare. But if you do have it, ingesting anything that comes from a mammalian source can cause a reaction. 

This formula is derived from porcine kidney protein extract (pork).  

If you have Alpha-gal, you may want to talk with your provider about trying NaturDAO instead. It’s made from legume enzymes.  

We’re not sure yet how effective the legume-based DAO is compared to Histamine Digest 360, though. So, we’d love to hear from you if you do try it. 

IgE Pork Allergy or High IgG Pork Sensitivity 

Another reason DAO supplements may not work for you? You have an IgE pork allergy or a high IgG pork sensitivity. 

In this case, Histamine Digest 360 won’t be right for you until those antibodies are gone. Like you just read, this formula comes from porcine sources. 

However, you may be able to take beef kidney instead. 

Some beef kidney supplements can be better tolerated, generally speaking. But they are inherently higher histamine.  

They also aren’t as potent as a DAO supplement like Histamine Digest 360. But I want you to have some options to consider if you can’t take DAO from porcine sources.

You may have to try it to see how your body balances out the good histamine-degrading properties of diamine oxidase (DAO) with the higher histamine supplement. 

It may be that the overall benefits outweigh the additional histamine in the supplement. 

It’s important to remember that everyone’s level of intolerance is different. We truly are each unique. 

My Success with the DAO Enzyme 

Diamine Oxidase (DAO) has given me back more foods in my diet. 

And I don’t eat out a lot, but I can now. It feels like I have my life back again. 

I enjoy going out with my hubby for date night again. I like being able to meet up with friends for lunch. 

I hope the new Histamine Digest 360 DAO supplement will help you get back some of the foods and experiences you love, too. 

>>>>>You can get the best DAO here (US and Canada)

Histamine Digest 360 Diamine Oxidase by Diem

More Histamine Intolerance Posts

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Yacoub, M., et al. (2018). Diamine Oxidase Supplementation in Chronic Spontaneous Urticaria: A Randomized, Double-Blind Placebo-Controlled Study. Abstract – International Archives of Allergy and Immunology 2018, Vol. 176, No. 3–4 – Karger Publishers. 


  1. Sal

    Do you know a DAO enzyme supplement that is not made from pigs? I have a massive food sensitivity to pork?

    1. Zeresh

      As stated in article NaturDao, it is the one I use for my son.

      1. Suz, Mast Cell 360 Team

        Thanks for letting us know! Best wishes to you and your son for 2023!

  2. Melissa gonzales

    Is there any type of other nutritional deficiency that will alter Dao? Like the old you cant take this unless you take this too thick? I mean co factors. Just alittle bitter because the naturopath I trusted with more money than ive spent in my life shelled out so many supplements at me that it actually activated the mast cells. I believe that I stand with histamine intolerance maybe a sleeping lion inside me called mast cells. But she poked and poked at him and the last 2 years have been just awful. Obviously I stopped seeing her. And I still get very sad thinking about all the trust I lost. In healers and my own body. I was doing so well until the protomorphegens were fed to me. Im sure you know the brand im speaking of. She just kept saying all these other things that it was that didn’t make any sense. Im now more sensitive than ever before but have a small tolerance for some supplements. I think. I know that when i stop taking the few I do take i feel alittle worse. And I know that I have to tread lightly with supplements. But ive wanted to take Dao since forever. She didn’t like anything that wasn’t of this particular brand of supplements so it wasn’t even an option. Im taking the loritadine and the pepcid along with my anxiety meds each day. Im desperately looking for something to help the muscle pain and the constant reactions. But I have slowly been adding things and telling my mind to stop,stop,stop and distract. I just wasn’t sure if by trying a Dao I’d fall into the cofactor trap. I do know that its real however. In me for sure. Thanks for any advice 🙏

  3. Melissa gonzales

    I meant trick not thick. Lol first sentence and go old auto correct.

  4. Lien Nguyen

    Hi, I bought dao and tried it for the first time today. After lunch, I had cramps which subsided after about an hour. Do you think this is a normal reaction / the dao breaking down histamine? Or do you think it’s more of an allergic reaction and I need to find a different brand? Thank you!

    1. Suz, Mast Cell 360 Team

      Hi Lien,
      It’s hard to say without knowing your history. A couple things to consider: have they tried anything else new including a new food? It’s often helpful to keep a journal for food and supplements if you are not sure what may be causing reactions for you. Another thing to consider is how much of the DAO did you take? For the Mast Cell 360 clients, we usually say “start with a drop or sprinkle” and slowly build up if you are tolerating it. Again, we can’t say exactly what the best course for you might be so be sure to talk with your doctor or practitioner. If you do decide to try it again, go very slowly when introducing it.

      Suz, Mast Cell 360

  5. Jason Klinger

    i dont see this being any better. many people react to cellulose and ascorbyl palmitate

  6. Morten Krog

    Hi, does it breaks down the histamine release from eating oxalates and salicylates, digesting also?

    1. Suz, Mast Cell 360 Team

      Hi Morten,
      DAO helps reduce histamine in the gut, which will reduce it systemically because the histamine left in the gut gets dumped into the bloodstream.

      1. Ryan

        I see one on Amazon with vitamin c instead of B, is this the new formulation or is that the new formulation?

        1. Suz, Mast Cell 360 Team

          Hi Ryan, We just came out with the DAO with B with is Beth’s custom formula. Currently that formula is only available through Mast Cell 360 for clients, but we are hoping to have that open to the public in the very near future!

  7. Morten

    Is it effective to take if you are unlucky and I get a reaction to something you normally tolerate and then take a dao shortly after the onset of the reactions? Or hours later? It should, right?

    1. Suz, Mast Cell 360 Team

      Hi Morten,
      Everyone is different so we can’t say if and how this will work for you without knowing more about your case and health history. DAO is one of the top supplements Beth recommends. So if your reactions are related to histamine intolerance, this might help. Beth will often take it before meals. DAO works to reduce histamine in the gut which will reduce it systemically because the histamine left in the gut gets dumped into the bloodstream. If you are already experiencing reactions, you might want to consider some of the other supplements that have histamine lowering properties, like perilla seed extract. You can learn more about that here:

  8. Morten


    I tried Histamine Block after the talks we have had here on this site, I reacted so bad.

    SO I changed the capsules with gellan gum out to hypromellose+water caps, now it works! Holy fuck. No reactions and doing much better!!

    So many can’t tolerate gellan gum, thats fermented!!!

    I’m now convinced that I probably can tolerate ancestral beef kidney also! Silica and gellan gum out of supps!!!

  9. Zeresh

    Hello Beth,
    Thank you for all the amazing and detailed information on your site. It has helped me, more directly my son, a lot.
    After much investigation, I tested him for a DAO deficiency and it came back with very low levels. I started him on a low histamine diet and supplementing with NaturDao and I have seen a difference (still early stages). However, he is 14 years old and as you can imagine it is a challenge because I can’t be too restrictive. Also, he does not swallow normal size pills, so it is hard to give him supplements, I often resort to cutting in small pieces or opening capsules and mixing with food, but I wonder how much this affects efficacy.
    His symptoms are daily congestion and rhinitis, asthma (worse in winter), allergies to animals, and cold urticaria. I have also been trying to get to the root cause and heal his gut. I am in Spain and unfortunately there aren’t many good options for functional medicine doctors or nutritionists.
    Anyway, I was mostly writing to thank you, but since I shared my experience, if you or any of your readers can offer advice for me on how to best help my son I would be happy to read them. Again, thank you sooo much, histamine intolerance is so confusing, you help make it easier! ❤

    1. Jamie, Mast Cell 360 Team

      Hi Zeresh, It is hard to say what might be the root cause of your son’s histamine and gut issues since we are unfamiliar with his individual case. We’re sorry to hear he is going through that, but wow is he lucky to have a momma like you doing everything to help him. We work with a very sensitive population of clients, and often have them open supplements to add to food as they build their tolerance, so it is great that you are able to assist him by using DAO in that way and hopefully you are able to see a difference in his symptoms.

  10. Susan

    Hi, Beth. Thanks for publishing all of this information. I’m wondering if taking DAO even when you haven’t eaten, but are having a histamine reaction, will help you with residual histamine and help you feel better more quickly?

  11. Rissa

    Hi Beth! You mentioned taking 3+ DAO before each meal…I wondered if you personally take DAO before eating (low histamine) snacks too? Just curious what most people do! Thanks!

  12. Christopher

    My partner needs DAO but cannot tolerate cellulose in any form. Such a shame that its within the supplement and not just the casing.

  13. Emma

    Hi. Not sure if comments are still being monitored on this blog? If they are, I was wondering if there’s a DAO enzyme recommended for those of us who are outside of the US so can’t order Beth’s? I’m in the UK. Thanks.

    1. Jamie, Mast Cell 360

      Hi Emma, I’m not sure what companies that make a DAO enzyme ship outside the US, but you can purchase Beth’s DAO from our webstore here: using a third party shipping option such as MYUS, which you can learn more about here:
      If you use them, you of course, do so at your own risk, and you’ll need to know your countries’ laws and customs regarding shipping supplements. That said, a few of our clients have shipped supplements to their homes outside the United States using these services, and had a good experience. Always do your own research as we aren’t involved with these companies and we can’t be responsible for, or able to help with any issues you might encounter with shipments through them.

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