Histamine Intolerance Test (DAO)

✔️ Use as a standalone test for histamine intolerance or add to other IgG food intolerance tests for a complete picture

✔️ Used by GPs and clinicians in over 40 countries

✔️ Conducted in specialised certified German labs

✔️ Undertaken with medically validated ELISA test method

✔️ Tested with blood serum for accuracy (food intolerance blood test)

What is DAO and histamine?

Diamine oxidase (DAO) is a key enzyme produced mainly in the gut that breaks down histamine from food and from your own cells. When DAO levels are too low, histamine can build up and trigger symptoms in the skin, gut, brain, and respiratory system even if you do not have a classic IgE allergy. ImuPro’s piece on the vital role of histamines in your body explains this in more detail. Histamine intolerance is best described as a reduced ability to clear histamine rather than being “allergic” to histamine itself.​

It performs many functions including regulating your:

• Sleep-wake cycle
• Body temperature
• Blood pressure
• Immune system.

Which foods are high in histamine?

High histamine foods include:

• Alcohol (esp. red wine and champagne)
• Cheese
• Seafood, fish (particularly tuna, swordfish) and fish sauces
• Raw meat sausages (e.g. salami, bacon)
• Sauerkraut
• Vegetables (e.g. tomatoes, spinach and eggplant)
• Fruits (e.g. strawberry, pineapple, banana)
• Chocolate
• Fermented foods.

Histamine intolerance

Most people are able to regulate histamine levels well because they produce the right amount of certain enzymes (including DAO), which break down excessive histamine in food and prevent it from accumulating.

However, if you don’t produce sufficient amounts of DAO and you eat a meal rich in histamine, you are likely to get an allergic type response.

Symptoms of histamine intolerance include:

• Hayfever
• Migraines
• Dizziness
• Gastrointestinal complaints
• Tachycardia (fast heart rate), arrhythmia (irregular heartbeat)
• Menstrual pain
• Asthma
• Depression
• Itching, red skin.

One simple test could identify the cause of these troubling symptoms and improve your quality of life.

Better still, if you wish to test for more potential food sensitivities or delayed IgG allergies, once you receive your results you can use the same blood sample.

Symptoms of histamine intolerance

Common histamine intolerance symptoms include digestive issues such as bloating, abdominal pain, diarrhoea or constipation, along with headaches or migraine, flushing, nasal congestion, hives, and itchy skin. Some people also notice fatigue, dizziness, low blood pressure or palpitations, and menstrual discomfort, especially after high‑histamine foods like wine, aged cheese, processed meats, or chocolate.

DAO histamine intolerance test

A DAO histamine intolerance test is a blood test that measures the activity of DAO in your serum to see whether you have a deficiency that could explain histamine‑related symptoms. ImuPro’s DAO test is offered direct‑to‑consumer in Australia and uses accredited laboratory methods to quantify DAO activity, providing a clearer picture than snapshot histamine measurements that fluctuate with diet and environment.​ You can explore this and other options on the ImuPro tests overview.

How the ImuPro DAO test works

With ImuPro, you order the DAO histamine intolerance test online, then attend a local pathology collection centre where a trained collector draws a standard blood sample. The separated serum is stable at room temperature for over a week and can be refrigerated for 3 weeks so there is no problem with stability. Samples are couriered to our laboratory in Germany every Friday, and results are emailed within 14 business days.

Understanding your results

If your DAO activity is low, your report will outline what your level means and suggest practical steps such as reducing high-histamine or histamine-releasing foods. DAO levels are generally stable, so a single low reading can be a strong indicator that histamine intolerance may be contributing to your symptoms.
If your DAO activity is within the normal range, it suggests that histamine intolerance is less likely to be the cause of your symptoms and further investigation may be helpful. In many cases, symptoms may instead be related to IgG-mediated food sensitivities, or you may have both histamine intolerance and IgG reactions occurring together.
Because histamine intolerance symptoms often overlap with food sensitivities, many people choose to combine the DAO test with an IgG food sensitivity panel to build a more complete picture of possible triggers.