DAO Supplement for Histamine Intolerance: What It Is and How It Works

Apr 24, 2025 Talib Ahmad Supplement Expert 91 Views

Ever notice headaches, hives, or digestive issues after eating foods like aged cheese, wine, or fermented snacks? You might be dealing with something called histamine intolerance—a condition where your body struggles to break down histamine properly. One of the key players in this process is an enzyme called diamine oxidase, or DAO. When DAO levels are low, histamine can build up and trigger a range of uncomfortable symptoms. That’s where DAO supplements come in. In this post, we’ll break down what DAO is, how it works, and why a supplement might be worth considering if histamine is wreaking havoc on your day.

What Is Histamine Intolerance?

Histamine intolerance isn’t an allergy—it’s more like a traffic jam. Histamine is a natural compound found in your body and in many foods. It plays a role in immune responses, digestion, and even acts as a neurotransmitter. But when too much histamine builds up and your body can’t break it down fast enough, that’s when problems start. (1,2)

This buildup can trigger a wide range of symptoms, including:

Headaches or migraines†
Skin flushing or hives†
Nasal congestion or sneezing†
Digestive issues like bloating, gas, or cramps†
Irregular menstrual cycles†
Anxiety or dizziness†

Unlike food allergies, which involve the immune system, histamine intolerance is about enzymatic imbalance—specifically, a lack or deficiency of the enzyme that breaks histamine down in your digestive tract. That enzyme is DAO (diamine oxidase), and when it’s not doing its job efficiently, histamine can accumulate and cause symptoms that mimic allergies or food sensitivities. (1,2)

In short: it’s not what you’re eating, it’s what your body can’t process properly.†

What Is DAO (Diamine Oxidase)?

DAO, short for diamine oxidase, is an enzyme your body produces to help break down histamine—specifically, the histamine found in the foods you eat. Think of DAO as your body’s natural defense against histamine overload. It’s mainly produced in the lining of your small intestine, as well as in the kidneys and thymus, and its job is to prevent excess histamine from entering your bloodstream through digestion. (1,2,3)

Here’s the catch: if your body doesn’t make enough DAO, or if the enzyme isn’t working efficiently, histamine can build up and trigger symptoms of histamine intolerance. †

Several things can cause low DAO levels, including:

Chronic gut inflammation (like IBS or leaky gut)†
Genetics (some people naturally produce less DAO)†
Certain medications, like NSAIDs, antibiotics, and antidepressants†
Alcohol, which not only blocks DAO but also increases histamine levels†

When DAO production is low or the enzyme is blocked, your body can’t keep up with histamine from food—and that’s when symptoms start to appear. DAO supplements are designed to fill this gap and help support your body’s ability to process histamine more effectively.†

How DAO Supplements Work:

DAO supplements work by giving your body a temporary boost of the enzyme it may be missing. These supplements typically contain diamine oxidase sourced from animal tissue (usually pig kidney extract), and they’re designed to be taken right before meals—especially those that may contain high-histamine foods.†

Here’s how it works:
When you take a DAO supplement before eating, it sits in your digestive tract and helps break down the histamine found in your food before it can be absorbed into your bloodstream. This helps reduce the chances of triggering symptoms like headaches, flushing, or stomach issues.†

It’s important to understand that DAO supplements don’t lower histamine already circulating in your body—they only work on the histamine from food that’s being digested in the moment. That’s why timing is key. If you take a DAO supplement after eating, it likely won’t be as effective.†

While DAO supplements don’t cure histamine intolerance, they can act as a helpful support tool, especially if you’re dealing with occasional reactions or need a little buffer when eating out or traveling.†

Who Might Benefit:

DAO supplements aren’t for everyone, but for the right person, they can make a big difference. If you’ve been dealing with recurring, unexplained symptoms after eating certain foods, a DAO supplement may help manage those reactions—especially if you suspect histamine is the trigger.†

You might benefit from a DAO supplement if you:

React to high-histamine foods like aged cheese, red wine, fermented foods, or cured meats†
Experience symptoms like headaches, skin flushing, a runny nose, or digestive discomfort after meals†
Have a known DAO deficiency or chronic gut conditions like IBS, SIBO, or leaky gut†
Take medications that interfere with DAO activity (such as NSAIDs, antibiotics, or antidepressants)†
Need short-term support while traveling or eating foods outside your usual low-histamine diet†

It’s worth noting: DAO supplements don’t treat the underlying cause of histamine intolerance—they’re a tool to manage symptoms. Long-term support may also include gut healing, dietary changes, and identifying other possible triggers. But if you need fast, meal-by-meal support, DAO can be a useful addition to your routine.†

What to Look For:

Not all DAO supplements are created equal, and since you’re relying on them to help manage symptoms, quality really matters. Here are a few key things to check before choosing a DAO supplement:

Source of DAO
Most effective DAO supplements have traditionally been derived from porcine (pig) kidney extract, which closely resembles the enzyme your body naturally produces. However, plant-based DAO sourced from pea sprouts has emerged as a viable alternative, offering similar histamine-degrading activity.†

If you’re vegetarian or prefer plant-based products, look for options that specifically list Diamine Oxidase (DAO) from plant sources—some general gut health supplements may be marketed for histamine support but don’t contain the active DAO enzyme. Always check the label to ensure you’re getting a true DAO supplement.†

Enzyme Activity (Measured in HDU)
Look for products that clearly state the HDU (Histamine Degrading Units) on the label. Higher HDU usually means more enzymatic activity. A common dosage range is 10,000–20,000 HDU per serving.†

Clean Formula
Since people with histamine intolerance are often sensitive to additives, choose a product that’s free of unnecessary fillers, artificial colors, preservatives, or ingredients that might trigger reactions (like gluten, soy, or lactose).†

Proper Delivery Format
Capsules are the most common and are usually taken 15–30 minutes before eating. Be sure the product is intended for use with meals, not as a daily multivitamin.†

Finding the right DAO supplement might take a little trial and error, but starting with a clean, properly dosed formula gives you the best chance at getting real relief.

Other Ways to Support Histamine Balance:

While DAO supplements can help manage histamine from meals, they’re just one part of the bigger picture. If histamine intolerance is affecting your daily life, consider these additional ways to support balance and reduce symptoms:

Follow a Low-Histamine Diet

Avoid or limit high-histamine foods like:

Aged cheeses and cured meats†
Fermented foods (sauerkraut, kombucha, soy sauce)†
Alcohol, especially red wine and beer†
Leftovers (histamine increases as food sits). Sticking to fresh, minimally processed foods can make a noticeable difference.†

Support Gut Health

A healthy gut lining helps regulate histamine and DAO production. Focus on:

Probiotics (but be selective—some strains may increase histamine)†
Digestive enzymes†
Anti-inflammatory foods (like omega-3s and bone broth)†

Avoid DAO Blockers

Certain medications and substances can block DAO activity, including:

NSAIDs (like ibuprofen)†
Antidepressants (especially MAO inhibitors)†
Alcohol†
Energy drinks or green tea extract (in large amounts)†
If possible, work with a healthcare provider to adjust any medications that may be contributing.†

Reduce Histamine Triggers in Your Environment

Non-food sources can also contribute to histamine buildup:

Pollen and mold†
Pet dander†
Stress (yes, it can raise histamine levels too!)†

Managing histamine intolerance often requires a multi-angle approach. DAO supplements can help with food-related symptoms, but building habits that support your overall histamine balance gives you a stronger foundation for long-term relief.

Where To Buy?

If you’re exploring ways to support your body’s ability to manage dietary histamine, consider adding DAO supplements to your regimen. Two reputable options are available:

1. Life Extension Food Sensitivity Relief with Diamine Oxidase (DAO)

This supplement features a plant-based DAO enzyme sourced from pea sprouts, designed to aid in the breakdown of histamine-rich foods. It’s formulated to help relieve occasional non-allergy digestive discomfort associated with dietary histamine sensitivity.†

Key Features:

Plant-based DAO from pea sprouts†
Supports digestion of histamine-rich foods like cured meats and aged cheeses†
Vegetarian, gluten-free, and non-GMO†

You can purchase this product directly from SameDaySupplements.com!

2. Solaray DAO Enzyme

Solaray’s DAO Enzyme supplement delivers 4.2 mg of diamine oxidase per serving, supplying 60,000 histamine degradation units (HDUs). It’s designed to help the body metabolize histamine from food.†

Key Features:

Plant-based DAO sourced from pea sprouts†
Enteric-coated capsules to protect the enzyme during digestion†
Vegan and gluten-free†

Both supplements are formulated to support the breakdown of dietary histamine, potentially alleviating occasional digestive discomfort. As always, consult with a healthcare professional before adding new supplements to your routine.†

Wrapping Up!

This marks the end of our blog on DAO Supplements for histamine intolerance. Thank you for reading! And as always, if there is something that isn’t clear, another question you might have, or if you have another idea for a blog, email us!

Are you looking for more to read? Check out some of our other blogs!

Warnings And Side Effects:

Not intended for use by persons under 18. If you are pregnant, nursing, taking any medications, or have any medical conditions, consult your doctor before use. Discontinue use and consult your doctor if any adverse reactions occur.

Disclaimer:

†Please note the intention of the information provided is for reference only. Furthermore, we are in no way providing medical advice or instruction. Instead, the information provided in this guide/blog utilizes anecdotal information and available studies/reviews. While we aim to maintain and display accurate information, we can’t guarantee it represents the latest product formulation or information. Therefore, please visit the manufacturer’s website if you have any concerns. Also, the information above does not represent our views here at Same Day Supplements. Instead, these are the manufacturers’ and users’ views and information. Additionally, the Food and Drug Administration has not evaluated these statements. Finally, these products aim not to diagnose, treat, cure, or prevent disease or illness.