So you’re probably wondering what histamines are, and what they have to do with your period right? We’re all familiar with antihistamines – those medications that stop the “itchy, sneezy, watery eyes” situations that come up mostly during allergy season or when we are allergic to another substance (other than pollen).

Well, histamines are what antihistamines work against!

What are histamines?

Histamines are chemicals that are stored in immune cells known as Mast Cells, and are involved in nerve transmission and immune response regulation. When Mast Cells are triggered, they release histamines, which then trigger those responses we all know so well – itchiness, puffiness, swelling or hives – which are all caused by your immune system.

Mast cells are not the only source of histamine in the body. Histamine can also be produced by bacteria living in the gut. In fact, certain gut bacteria not only produce histamine, but they can also help regulate it and even break it down. This is important so keep reading.

Important to note: Bacteria found in fermented foods like sauerkraut, kimchi, kombucha, and kefir also produce histamine.

Where do you find histamines?

Basically in all the good stuff! 🙂 I’ve noticed most people tend to react most strongly to the fermented foods on this list, but it’s important to know the other food triggers too.  

  • Fermented, cured, or soured foods, such as yogurt, luncheon meat, pickles, and sour cream
  • Aged cheeses, such as cheddar and parmesan, and smoked fish
  • Citrus fruit and dried fruits such as apricots and raisins
  • Alcoholic beverages, especially wine and beer
  • Certain nuts, including walnuts, peanuts, and cashews
  • Avocados, eggplant, spinach, tomatoes and chocolate

What is Histamine Intolerance?

When a person has a histamine sensitivity or intolerance, certain foods or environmental stimulants can cause a host of symptoms.

Symptoms of Histamine Intolerance:

  • flushing
  • sneezing
  • itching and hives
  • headaches and migraines
  • wheezing
  • swelling
  • anxiety
  • runny nose or bloody nose
  • skin issues like acne and eczema
  • menstrual cramps
  • PMS-like symptoms at ovulation, and
  • difficulty sleeping (hint: this is why antihistamines make you sleepy)

While genetics and food allergies certainly play a role in histamine sensitivity, gut dysbiosis makes things much worse. People with leaky gut or small intestine bacterial overgrowth (SIBO), or some other type of gut bacterial imbalance are much more prone to histamine sensitivity.

Histamine And Progesterone

Many women are in a lower progesterone state. This includes those with PCOS, as well as those who are having anovulatory cycles or not ovulating consistently. This is because the act of ovulation triggers progesterone production from the little follicle the egg was released from. 

Keep this in mind as you read the next two paragraphs…

We have a gene called the DAO gene that creates the DAO enzyme. If there are genetic variants on this gene, you may not make the DAO enzyme sufficiently. This is important because the DAO enzyme is located in your gut, and it is responsible for breaking down histamine contained in the food you eat.

Unfortunately, SIBO, candida and parasites, leaky gut, inflammatory bowel diseases like Crohn’s or ulcerative colitis, and too many high histamine foods and alcohol, can also cause the DAO enzyme to not work so well.

So here’s the connection to progesterone – the DAO enzyme function is naturally supported by progesterone. Estrogen has the opposite effect – it down-regulates the DAO enzyme.

This is why women with PCOS or inconsistent ovulation may have more histamine issues than women who are regularly ovulating and producing sufficient progesterone.

Histamine and Estrogen

Estrogen is an immune system stimulator. It actually triggers the release of histamine from the mast cells in the ovaries and uterus. The more unopposed estrogen we have roaming around our body, the more histamines are produced. And unfortunately, the more histamines we have, the more estrogen is produced by the ovaries.

Ugh, and around and around we go in this cycle.

The estrogen connection is why women may feel really terrible at ovulation (when estrogen is high) and notice an improvement in their histamine-related problems during the second half of their cycle when estrogen drops and progesterone rises. It’s frustrating for many women because they think they’re supposed to feel amazing at this time of the month, and instead they are plagued by headaches, fatigue, bloating, itching, insomnia, irritability and gut issues.

Is this you? Please share in the comments below!

It’s almost like PMS during ovulation. And while the symptoms improve for many women in the second half of their cycle (when progesterone is high), they come back as progesterone drops towards the end of the cycle. And hello PMS symptoms all over again!

Histamine, Menstrual Cramps & Abnormal Uterine Bleeding

You know how I just mentioned that histamines are released by mast cells in the uterus? Well, they play a role in uterine muscle contractions during menstruation and also during birth. (1) Mast cells also produce prostaglandins, which play a key role in uterine contractions.(2)

Therefore, higher numbers of mast cells and more mast cell activity at menstruation could be a trigger for more period pain. 

This is another reason to consider histamine intolerance if you’re experiencing cramps and have tried implementing other measures to address them – change in diet, supplements, exercise and physical work (pelvic physical therapy, abdominal massage therapy or vaginal steaming).

In addition, there is some evidence that excessive uterine bleeding is associated with histamine release due to the simultaneous release of heparin and heparin-like anti-coagulants. Heparin is a blood thinner, which prevents blood clotting, and higher levels due to higher mast cell activity could cause heavier bleeding. (3)

Histamine & Chronic Stress (and the DAO and HNMT Enzymes)

As I said, histamines are stored inside cells called mast cells. What I think is generally missed when we’re talking about all this histamine business is that mast cell production of histamine and other pro-inflammatory mediators increases when people are under stress – and that’s all kinds of stress by the way. It could be a physical injury, or it could be psychological stress. Almost across the board, it is psychological stress. That chronic unmitigated stress we always hear about.

Chronic stress increases the excretion of magnesium and some of the B vitamins. Remember that!

The body has enzymes to break down the histamines. They’re called DAO (diamine oxidase) and HNMT (histamine n-methyltransferase). Both of those enzymes require specific nutrients to work properly.

The DAO requires copper, magnesium and vitamin B6 and C. The HNMT requires methyl donors like B12 and folate. I’ll get to that in a moment. 

And what happens when people are under stress? They lose magnesium, B vitamins and copper goes rogue. I explain the copper problem in this post. They lose the very nutrients that they need to make those enzymes work to control the histamine response. And this can go on for years and years unaddressed. 

What to do if you have a histamine intolerance

Ultimately, histamine intolerance and/or Mast Cell Activation Syndrome (MCAS) is often driven by immune dysregulation, and this is most often driven by chronic unmitigated stress and underlying gut problems. Remember, histamine can also be produced by certain bacteria living in the gut, while other bacteria can break it down.  

This is particularly important in conditions like endometriosis. I discuss the link between endometriosis and mast cell/histamine problems in this post.

Solutions for Histamine Intolerance:

#1. Avoid foods high in histamines

First, I suggest avoiding the foods below for just 2-4 weeks to see if there is improvement in symptoms. This is restrictive but I promise you’ll see results pretty quickly and you’ll know whether this might be an issue for you. 

  • Fermented, cured, or soured foods, such as yogurt, deli meat, pickles, and sour cream
  • Aged cheeses, such as cheddar and parmesan
  • Smoked or canned fish
  • Dried fruits such as apricots and raisins
  • Alcoholic beverages, especially wine and beer
  • Certain nuts, including walnuts, peanuts, and cashews
  • Avocados, eggplant, spinach, tomatoes and chocolate

Focus on nutrient stores – we need vitamins B6, B9, B12, C, copper and magnesium to support the DAO & HNMT enzymes (these break down histamine in the body). High nutrient foods like liver, red meat, shellfish & sea vegetables are a must. ⁠

#2. See a doctor/practitioner with a specialty in gut health

As I’ve said repeatedly, histamine intolerance is not an isolated condition. It is driven by multiple factors – chronic stress, immune system dysregulation, gut dysbiosis and inflammation, estrogen/progesterone imbalance. When is anything ever isolated? LOL

So I recommend working with a functional medicine doctor or naturopathic doctor, or a practitioner who is trained in identifying and treating gut-related conditions, to address any underlying gut issues and infections, and other contributing factors to your symptoms. And seriously, it’s time to start addressing the stress in your life. This looks different for different people.

#3. Supplement with Quercetin and/or Nettles

I am a big fan of Quercetin, a flavonoid which works like an all natural anti-histamine – stabilizing the effects of histamines released from mast cells. It also doubles as a leaky gut and pain reliever. There are lots of quercetin options available but I’ve created a Histamine Help Supplement Protocol in my supplement dispensary with my recommendations. You’ll have to create an account to see the protocol.

You’ll get 15% off for every order and free shipping on orders over $50. Follow the directions on the label and remember, this is not a root cause solution – you’ve gotta figure out why your immune system is acting this way! 

I’m also a big fan of nettle tea!

Stinging nettle contains vitamins A, C, and K, as well as vitamins B1, B2, B3 and B9 (or folate). It’s also a good source of calcium, magnesium, potassium, phosphorus, iron, and silica, and it’s got antioxidant, anti-inflammatory, and antimicrobial properties.

What’s really cool is that nettle acts like an antihistamine, lowering levels of histamine in the body. This is especially helpful for anyone with high histamine levels or a problem with clearing histamine, and it works well for hay fever, seasonal allergies or allergic reactions.

Can’t I just take an antihistamine?

You could, but I do not recommend doing that long term! Quercetin and nettles are a better bet than antihistamines because they can disrupt your cervical fluid production, causing less fertile quality cervical fluid. This is because antihistamines are mean’t to “dry out” your bodily fluids (like phlegm!). There are other side effects as well, so as I said, longterm use is a bad idea. 

#4. Avoid probiotics with strains that increase histamine in the gut

Stay away from probiotics that contain strains that produce histamine in the gut. And use a probiotic that is “histamine friendly”. I use and recommend Seeking Health Probiota HistaminX which contains specific Bifido strains that help break down histamine in the gut.

You’ll find it in my Histamine Help Supplement Protocol in my dispensary.

#5. Try Histamine Digest and/or Histamine Nutrients by Seeking Health

Histamine Digest (formerly Histamine Block) is an amazing product that contains DAO, the enzyme that is responsible for breaking down histamine ingested into the body.

In addition to DAO, Histamine Nutrients (formerly Histamine Block Plus) contains B vitamins (particularly B6 which supports DAO activity) and other nutrients which further help support breakdown of histamine in the body. I use both myself and recommend them to clients in conjunction with Probiota HistaminX.

You’ll find these products and so many more recommended supplements in my Fix Your Period Supplement Dispensary. As stated above, I have created a Histamine Help Protocol for those with histamine problems and it includes all of the above supplement recommendations at 15% off!

#6. Address anovulatory cycles so you can produce more progesterone

If you’re not ovulating or ovulating inconsistently, look into why that is and start to take action. There are lots of reasons for anovulation or inconsistent ovulation, and it’s important to address them so you can ovulate regularly and produce more progesterone. This will help support DAO enzyme function.

I explain this in detail in the first two chapters of my book Fix Your Period.

#7. Support your body’s estrogen detoxification pathways

I’ve said this sooo many times but I’ll say it again. Good gut and liver function are crucial for supporting estrogen detoxification from the body. Estrogen is a use it and lose it hormone, which means you wanna use it and then get rid of it so it doesn’t recirculate.

See Week 4 Liver Detoxification in my book Fix Your Period

Hopefully implementing these solutions helps improve your histamine issues, which will go far to help alleviate the menstrual cycle problems you’re experiencing!