Name: DAO Enzyme
Brand: Seeking Health
SKU: HIS-DIG-CAP
Price: 40.0 USD
Availability: InStock
Rating: 4.8 (831 reviews)

Why I Formulated DAO Enzyme

This one is personal. My entire family carries genetic variations in the DAO gene. This means we all produce less diamine oxidase enzyme than we need. That translates to a reduced ability to process histamine. Growing up, we lived with the consequences. Nosebleeds. Eczema. Loose stools. Headaches after certain meals. We just thought that was normal.

Once I understood the biochemistry, everything clicked. Our DAO enzyme simply couldn't keep up with the histamine coming in from food, drinks, and our own gut bacteria.

When I learned that supplemental DAO enzyme existed, I was genuinely excited. Finally, a way to directly support what our bodies weren't doing well on their own.^†

The problem was finding one that actually worked. Most DAO enzyme supplements on the market are weak in performance and loaded with questionable inactive ingredients. I tried several for my family and the results were inconsistent at best. It wasn't until I switched to DAOgest®, a cleaner, patented, and lab-tested DAO enzyme derived from porcine kidney extract, that we experienced real, consistent results. My kids could eat without the nosebleeds. My wife's head felt clear after dinner. I stopped dreading leftovers.^†

That's why I put DAOgest® in DAO Enzyme. Because my family uses this. And I wouldn't put anything in a Seeking Health product that I wouldn't give to my own children.

How to Use It

With meals: Take 1 capsule before eating or drinking anything high in histamine such as aged cheeses, wine, fermented foods, cured meats, leftovers, citrus, or overly ripe fruit. This is the most common use and where most people notice the most support.^†

On an empty stomach: This is the one most people miss and is actually quite a genius trick. Your gut bacteria and your gut's immune system also produce histamine. If you have dysbiosis, SIBO, or an overactive gut immune response, try taking 1 capsule on an empty stomach. If you feel better within 30 minutes, that tells you your microbiome or gut immune system is producing excess histamine. Continue using it this way as needed.^†

For children: Ages 4 and up. Open the capsule and sprinkle on a bite of applesauce if they can't swallow it.

During pregnancy: With your healthcare professional's approval. Your placenta produces massive amounts of DAO but not until the 2nd trimester, which is exactly when most morning sickness eases. Supporting healthy histamine levels during the 1st trimester may support comfort.^†

While breastfeeding: Histamine from your gut absorbs into breast milk. Infant colic is associated with higher histamine levels in breast milk. Supporting your own histamine balance may support comfortable feeding for your baby.^†

When to Reduce or Stop

DAO Enzyme is what I call a palliative supplement. It provides the enzyme your body needs right now, but it doesn't fix the underlying reason your DAO may be low. The goal is to heal your gut lining, rebalance your microbiome, and calm your immune system so your body's own DAO enzyme works well on its own.

As you make progress in those areas, you'll naturally need less DAO Enzyme. Some people go from taking it at every meal to only when they eat out or travel. Others find they eventually only need it during high-histamine seasons or stressful periods. Let your body guide you.^†

If your stools become harder to pass, that's a sign you may be taking too much. High histamine in the gut is associated with loose stools so when you lower it effectively, things can firm up more than expected. Simply reduce your dose to mealtimes only, or take a break. If things normalize, adjust accordingly.^†

Supportive Supplements

DAO Enzyme handles the histamine that's already in your gut. But histamine intolerance is multifaceted. Here's how I recommend building a complete support system.^†

ProBiota HistaminX — Many common probiotic strains actually produce histamine in your gut — including L. casei, L. fermentum, L. bulgaricus, and Streptococcus. If you've ever tried a probiotic and felt worse, that's likely why. ProBiota HistaminX contains only histamine-friendly strains that support microbial balance without adding to your histamine burden. Take 1 capsule in the morning upon waking. While DAO Enzyme handles today's histamine, ProBiota HistaminX works on supporting microbial balance so your body produces less excess histamine over time.^†

Bile Nutrients — If fatty meals leave you bloated, nauseous, or uncomfortable, your bile flow may need support. Healthy bile is essential for fat digestion, bowel regularity, and maintaining a balanced microbiome. Poor bile flow contributes to the kind of bacterial imbalances that increase histamine production. Take Bile Nutrients before dinner alongside your DAO Enzyme to support healthy bile flow.^†

Histamine Nutrients — DAO breaks down histamine in your gut, but histamine is also broken down inside your cells by another enzyme called HNMT, which requires SAMe and healthy methylation. Histamine Nutrients provides the cofactors for all five enzymes in your histamine pathway — DAO, HNMT, MAOA, MAOB, and ALDH. Take 1–2 capsules with food for system-wide histamine metabolism support, or in the evening to support healthy sleep onset.^†

Histamine Report — If you want to understand why your histamine is elevated, run your raw genetic data through our Histamine Report. It analyzes your DAO, HNMT, MAOA, MAOB, ALDH, and other histamine-related gene variants so you can see exactly which pathways may need the most support.

Who Needs DAO Enzyme: 18 People Who May Benefit

If you've ever felt worse after eating and couldn't figure out why, you're not alone. Histamine intolerance affects an estimated 1 to 3% of the population, and many more go undiagnosed for years. Below are 18 common patterns we see in our customers. If you recognize yourself in even one of them, DAO Enzyme may be worth trying.^†

1. The person who bloats after almost every meal.

You eat dinner and spend the rest of the evening uncomfortable. Bloating, fullness, abdominal discomfort, gas. You've tried elimination diets and digestive enzymes with limited results. DAO Enzyme provides the patented DAOgest® enzyme to support healthy histamine metabolism in your digestive tract.^†

Research: Schnedl et al. (2019) demonstrated that all GI symptoms improved significantly during 4 weeks of DAO supplementation in histamine intolerance patients. Symptoms returned when supplementation stopped. (1)

2. The person who dreads eating out.

Restaurants, dinner parties, road trips, travel. Every meal you don't fully control feels like a gamble. You've become the person who eats before going out or brings your own food. DAO Enzyme is small enough to carry anywhere. Take 1 capsule before eating to support healthy histamine levels when you can't fully control what's on the plate.^†

Research: Schnedl et al. (2019) reported improved quality of life metrics alongside symptom reduction during DAO supplementation. (1)

3. The person who reacts to wine, aged cheese, or fermented foods.

A glass of wine, a slice of aged cheese, sauerkraut, kimchi, or kombucha. These are among the highest histamine foods and beverages. Your reaction isn't a food allergy. It may be a sign that your body's DAO enzyme isn't keeping up with dietary histamine. DAO Enzyme supports your body's normal enzymatic breakdown of histamine from food and drink.^†

Research: Maintz and Novak (2007) identified aged cheese, wine, and fermented foods as primary dietary histamine sources relevant to individuals with reduced DAO activity. (2)

4. The person who gets headaches after eating.

Post-meal headaches that no one can explain. You've seen your doctor, maybe a neurologist, and everything comes back normal. Histamine is metabolized by DAO in the gut. When DAO activity is low, unmetabolized histamine may enter circulation. DAO Enzyme supports healthy DAO activity in the digestive tract.^†

Research: Izquierdo-Casas et al. (2019) conducted a randomized double-blind trial showing DAO supplementation significantly reduced migraine duration by 1.4 hours. A separate study found 87% of migraine patients had DAO deficiency. (3, 4)

5. The person with skin reactions after eating.

Flushing, hives, itching, or eczema flares that seem connected to meals but aren't a true food allergy. Your body relies on DAO to metabolize dietary histamine. When DAO activity is insufficient, histamine levels may rise. DAO Enzyme supports healthy histamine metabolism at the digestive level.^†

Research: Yacoub et al. (2018) reported benefits of DAO supplementation in urticaria patients. Schnedl et al. (2019) confirmed skin symptoms improved during the supplementation period. (1, 5)

6. The person managing MCAS on a restricted diet.

You have mast cell activation syndrome or suspect it. Your diet is extremely limited and every meal feels stressful. DAO Enzyme provides enzymatic support for histamine metabolism in the gut. It does not affect mast cell activity itself, but it supports the body's normal breakdown of histamine present in the digestive tract from food, bacteria, and normal immune function.^†

Research: Comas-Basté et al. (2020) established that impaired DAO activity is a primary driver of histamine accumulation in the gut, contributing to symptom presentations that overlap with MCAS. (6)

7. The parent whose child reacts to food.

Your child (ages 4+) gets tummy aches, skin rashes, nosebleeds, wets the bed or behavioral changes after certain meals. Pediatricians can't find anything wrong. Children produce DAO too, and some produce less than they need. DAO Enzyme capsules can be opened and sprinkled on a bite of applesauce for children who can't swallow capsules.^†

Research: Jones and Kearns (2011) identified histamine as a key mediator in pediatric gastrointestinal and dermatologic responses. Pediatric DAO insufficiency is increasingly recognized in clinical practice. (7)

8. The person with unpredictable bowel habits.

Loose stools, urgency, or diarrhea that comes and goes without a clear pattern. You may have been told you have IBS. High histamine in the gut is associated with increased intestinal motility. DAO Enzyme supports healthy histamine levels in your digestive tract.^†

Research: Schnedl et al. (2019) confirmed that diarrhea and other GI symptoms improved significantly with DAO supplementation and returned during the follow-up period without it. (1)

9. The pregnant woman experiencing occasional nausea.

You're in your first trimester and uncomfortable. Your placenta naturally produces DAO in high amounts, but it doesn't reach peak levels until the 2nd trimester. DAO Enzyme provides supplemental diamine oxidase to support healthy histamine metabolism. Use with healthcare professional approval.^†

Research: Brew and Sullivan (2006) demonstrated that maternal DAO levels increase significantly during pregnancy, with peak activity between the 2nd and 3rd trimesters. (8, 9)

10. The woman whose food sensitivities vanished during pregnancy and returned postpartum.

You felt great for nine months. Then you delivered and your old patterns came back. During pregnancy, your placenta produced large amounts of DAO. Postpartum, that source is gone. DAO Enzyme provides supplemental diamine oxidase to support healthy histamine metabolism as your body readjusts.^†

Research: A 2025 observational study confirmed that histamine intolerance symptoms improved in 27 of 30 pregnant women, correlating with an 11-fold DAO increase. All participants experienced symptom return postpartum as DAO levels declined. (10)

11. The breastfeeding mom with a fussy baby.

Your baby seems uncomfortable after feeding, and it seems connected to what you eat. Histamine from the gut can be absorbed into breast milk. DAO Enzyme supports healthy histamine metabolism in your digestive tract, which supports healthy histamine levels throughout your body, including breast milk.^†

Research: Maintz and Novak (2007) identified the relationship between maternal gut histamine and breast milk histamine levels as clinically relevant for breastfeeding women with reduced DAO activity. (2)

12. The person who feels worse from probiotics.

You started a probiotic hoping to support your gut, and instead you felt more bloated, more flushed, more miserable. Common probiotic strains including Lactobacillus casei, L. fermentum, L. bulgaricus, and Streptococcus species produce histamine in the gut as part of their normal metabolism. DAO Enzyme supports healthy breakdown of histamine in the digestive tract, including histamine produced by gut bacteria.^†

Research: Comas-Basté et al. (2020) identified specific bacterial strains as histamine producers and noted the importance of supporting DAO activity for individuals with histamine intolerance. (6)

13. The person with a dirty DAO gene.

You've run a genetic report and discovered you carry SNPs in your DAO (AOC1) gene. Now you understand why you've always been sensitive to certain foods. Genetic variants can reduce your body's DAO enzyme production or function. DAO Enzyme provides supplemental diamine oxidase to support your body's histamine metabolism.^†

Research: García-Martín et al. (2015) demonstrated that DAO gene variants rs10156191 and rs2052129 are associated with reduced DAO activity, particularly in women. (11)

14. The person with chronic nasal congestion or sneezing.

Year-round stuffiness, post-nasal drip, or sneezing that doesn't match a seasonal pattern. It's not pollen. Histamine acts on receptors throughout the body, including the respiratory tract. DAO Enzyme supports healthy histamine metabolism in the digestive tract, where the majority of dietary histamine is normally processed by DAO.^†

Research: Schnedl et al. (2019) documented that respiratory symptoms including rhinorrhea, nasal congestion, and sneezing improved during DAO supplementation and returned during the follow-up period. (1)

15. The woman with monthly discomfort that feels disproportionate.

Cramps, bloating, and discomfort around your cycle that seem more intense than what others describe. Estrogen and histamine share a bidirectional relationship. DAO enzyme is naturally expressed in uterine tissue where it supports local histamine metabolism. DAO Enzyme provides supplemental diamine oxidase to support healthy histamine levels.^†

Research: The bidirectional relationship between histamine and estrogen in uterine tissue is well documented. DAO is expressed in the uterus and supports local histamine metabolism. (2, 12)

16. The person whose heart races after meals.

Your heart flutters or races after eating. Cardiology says everything is fine. Histamine acts on receptors in cardiovascular tissue. DAO is the body's primary enzyme for metabolizing dietary histamine in the gut. DAO Enzyme supports healthy DAO activity in the digestive tract.^†

Research: Schnedl et al. (2019) documented that cardiovascular symptoms, including tachycardia and palpitations, improved during DAO supplementation in histamine intolerance patients. (1)

17. The person on Metformin with new digestive discomfort.

You started Metformin for blood sugar management and noticed changes in your digestion or new sensitivities to foods that never bothered you before. Certain medications have been associated with reduced DAO activity. DAO Enzyme provides supplemental diamine oxidase to support healthy histamine metabolism while taking these medications.^†

Research: Maintz and Novak (2007) identified multiple medications, including oral antidiabetics, as factors associated with reduced DAO activity. (2)

18. The person with bladder discomfort connected to food.

Bladder urgency, pressure, or discomfort that seems to flare based on what you eat. DAO enzyme is naturally expressed in kidney and urogenital tissue where it supports local histamine metabolism. DAO Enzyme provides supplemental diamine oxidase to support healthy histamine levels.^†

Research: DAO is naturally expressed in kidney and urogenital tissues. Histamine and mast cell activity in bladder tissue are areas of active research. (13, 2)

Key Ingredients

Inside the Uncompromising Quality of Our Ingredients

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DAOgest^® (Diamine oxidase)

This patented enzyme, derived from porcine (pork) kidney extract, supports the healthy breakdown of histamine in many areas of your body —especially the small intestine, colon, placenta, kidney, appendix, testis, and prostate.^†

DAOgest® is a trademark licensed by BIOIBERICA, S.A.U

When taken with meals, DAO Enzyme helps break down histamine found in foods and drinks. Histamine will be at a healthy level, which will help eliminate feelings related to histamine intolerance.^†‡

When taken on an empty stomach, DAO Enzyme helps break down histamine produced by the microbiome or your gut’s immune system.^†

This is a great idea to try: Take 1 capsule of DAO Enzyme on an empty stomach to see if you feel better within 30 minutes.

Why would this be useful? High amounts of histamine are produced by an unhealthy microbiome or an overactive gut immune system.

If you feel better, continue using DAO Enzyme on an empty stomach as needed. DAO Enzyme supports a healthy histamine balance in the gut.^†

DAO Enzyme may support healthy levels of histamine within the small intestine, colon, kidneys, uterus, appendix, placenta, prostate, or testicles. This is very important as unhealthy levels of histamine within these areas contribute to problems locally or throughout the body.^†

Children 4 years of age and older may use DAO Enzyme. If they cannot swallow the small capsule, you may need to open it and mix in a bite of applesauce.

Breastfeeding women may use DAO Enzyme. Histamine gets absorbed from the gut and into breastmilk. If breastmilk has higher levels of histamine, the breastfeeding baby may experience colic. Infant colic is associated with higher levels of histamine. Support healthy levels of histamine in your breastmilk by taking DAO Enzyme.^†

Pregnant women may use DAO Enzyme if approved by a healthcare professional.

Occasional nausea and vomiting during pregnancy is associated with high levels of histamine. Levels of histamine in a healthy pregnancy decrease below values found in healthy non-pregnant women. This is because the placenta is designed to produce a lot of the DAO enzyme. However, sometimes, the levels of histamine exceed the ability of the placenta’s DAO enzyme to digest histamine.

In some complications of pregnancy, maternal blood histamine levels rise above those associated with a healthy pregnancy. Many of the complications of pregnancy, including preeclampsia, preterm labor, spontaneous abortion, and hyperemesis gravidarum, are associated with increased levels of maternal blood histamine. Supporting healthy levels of maternal blood histamine levels during pregnancy, especially during such complications, may support a healthy pregnancy.

Suggested Use

As needed, anytime, take 1 capsule before eating or drinking. Alternatively, as needed, take 1 capsule away from food or drink if wanting to support uterine comfort during the menstrual cycle, occasional nausea from pregnancy or healthy histamine levels in your digestive system. Capsules may be opened and sprinkled on a bite of food. Use as directed by your healthcare professional.^†

Suitable for

Bariatric, methyl-sensitive, pregnancy, breastfeeding, ages 4 and up

NOT Suitable for

Vegetarians, vegans, infants

Delivery Method

Capsules

Age Suitability

Adults, age 4 and up

How to Store

Keep closed in a cool, dry place out of reach by children.

What our customers say

Real reviews from real customers.

4.8

Rated 4.8 out of 5 stars

Based on 831 reviews

Total 5 star reviews: 738 Total 4 star reviews: 59 Total 3 star reviews: 14 Total 2 star reviews: 7 Total 1 star reviews: 13

97%would recommend this product

Reviews Summary

Customers say this supplement helps them enjoy a wider variety of foods more comfortably. Many reviews mention taking it before meals to support their dining experience. Common feedback includes its effectiveness for dining out and social occasions. Users appreciate its role in their daily routines, with several noting they carry it with them regularly. While most report positive experiences, a few mention varying results or concerns about cost. Reviews frequently highlight its value for dietary flexibility and mealtime comfort.

Customers Talked About

831 reviews

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LLewis
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I recommend this product
Rated 5 out of 5 stars
6 minutes ago
Favorite DAO Enzyme
I just pop one before having a high histamine food item. It has enabled me to have a larger variety diet.
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Gordon
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I recommend this product
Rated 5 out of 5 stars
17 hours ago
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A good find
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I recommend this product
Rated 5 out of 5 stars
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🌽Seek good health🥕
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References

Schnedl WJ, Schenk M, Lackner S, Enko D, Mangge H, Forster F. Diamine oxidase supplementation improves symptoms in patients with histamine intolerance. Food Sci Biotechnol. 2019;28(3):895-902.
Maintz L, Novak N. Histamine and histamine intolerance. Am J Clin Nutr. 2007;85(5):1185-1196.
Izquierdo-Casas J, Comas-Basté O, Latorre-Moratalla ML, et al. Diamine oxidase (DAO) supplement reduces headache in episodic migraine patients with DAO deficiency: a randomized double-blind trial. Clin Nutr. 2019;38(1):152-158.
Izquierdo-Casas J, Comas-Basté O, Latorre-Moratalla ML, et al. Low serum diamine oxidase (DAO) activity levels in patients with migraine. J Physiol Biochem. 2018;74(1):93-99.
Yacoub MR, Ramirez GA, Berti A, et al. Diamine oxidase supplementation in chronic spontaneous urticaria. Int Arch Allergy Immunol. 2018;176(3-4):268-271.
Comas-Basté O, Sánchez-Pérez S, Veciana-Nogués MT, Latorre-Moratalla ML, Vidal-Carou MC. Histamine intolerance: the current state of the art. Biomolecules. 2020;10(8):1181.
Jones BL, Kearns GL. Histamine: new thoughts about a familiar mediator. Clin Pharmacol Ther. 2011;89(2):189-197.
Brew O, Sullivan MHF. The links between maternal histamine levels and complications of human pregnancy. J Reprod Immunol. 2006;72(1-2):94-107.
Southren AL, Kobayashi Y, Sherman DH, et al. Diamine oxidase in human pregnancy. Am J Obstet Gynecol. 1966;96(6):808-813.
Improvement of histamine intolerance symptoms in pregnant women with diamine oxidase deficiency: an exploratory study. J Clin Med. 2025;14(13):4573.
García-Martín E, Martínez C, Serrador M, et al. Diamine oxidase rs10156191 and rs2052129 variants are associated with the risk for migraine. Headache. 2015;55(2):276-286.
Bonds RS, Bhatt R. The role of histamine in estrogen-associated urticaria. Curr Allergy Asthma Rep. 2023.
Shan L, et al. Mast cell and histamine involvement in interstitial cystitis/bladder pain syndrome. Neurourol Urodyn. 2019.