Choosing a DAO Supplement
Share
Thinking of Trying DAO? How to Choose a Diamine Oxidase Supplement
Not all DAO enzyme supplements are backed by the same level of evidence. Here’s what to look for before you buy.
By the OmneDiem Team · Updated
Choose a DAO supplement backed by independent, peer-reviewed human studies, third-party purity testing, and a clearly labeled potency in HDU. Most published human research on supplemental DAO has used porcine (pork kidney) DAO, which is the form OmneDiem uses.
What is DAO?
Diamine oxidase (DAO) is an enzyme your body makes to help break down histamine from food in the digestive tract.* Think of it like a drain in a sink: histamine from aged cheeses, wine, fermented and leftover foods flows in, and DAO helps it flow out.* A DAO supplement taken with meals is designed to add to that drain capacity.*
3 signs of a DAO supplement worth trying
Independent human research
Peer-reviewed studies run by third parties, not just the brand’s own data.
Third-party testing
Outside lab verification of purity and potency, with a Certificate of Analysis available.
Clear potency in HDU
Histamine Degrading Units tell you how much active enzyme is in each capsule.
Internal testing is a normal part of product development. But independent, peer-reviewed clinical research is the gold standard, because it’s the most objective way to show how an ingredient performs in people.
Porcine vs. pea-derived DAO: what’s the difference?
DAO supplements typically come from one of two sources. Here’s how they compare on the evidence that matters most.
| Porcine DAO (pork kidney) | Pea-derived DAO (plant) | |
|---|---|---|
| Published human studies | Yes — the form used in peer-reviewed human research on DAO supplements | We have not found published human clinical studies to date |
| Primary evidence source | Independent, peer-reviewed research | Manufacturer’s internal testing |
| Suitable for vegetarians/vegans | No | Yes |
| Used by OmneDiem | Yes (DAOgest®) | Not yet — see below |
Why OmneDiem uses porcine DAO
OmneDiem® DAO products use DAOgest®, a standardized, porcine kidney-derived DAO ingredient — the same form studied in published human research. We back it with third-party testing and published human research.
- Histamine Digest: 30,000 HDU of DAO per capsule
- Histamine Digest PureMAX: 40,000 HDU of pure DAO per capsule
- Third-party tested for purity and potency
Our plant-based commitment: We know many customers would prefer a plant-based option. We’re actively working with manufacturers and will move to a plant-based DAO once a source proves stable, active, and supported by human research.
Frequently asked questions
Is porcine or pea-derived DAO better?
Porcine DAO is the form used in published, peer-reviewed human studies on DAO supplements. Pea-derived DAO may be an option for people who avoid animal products, but we have not found published human clinical data on it to date.
How do I know if a DAO supplement is high quality?
Look for independent, peer-reviewed human research on the ingredient, third-party testing with a Certificate of Analysis, and a clearly stated potency in HDU per capsule.
What does HDU mean on a DAO label?
HDU stands for Histamine Degrading Units, a measure of the enzyme’s activity. A higher HDU means more active DAO per capsule.
When should I take a DAO supplement?
DAO is generally taken shortly before a meal or snack, since it works in the digestive tract on histamine from food.* Follow the directions on your product label, and talk with your healthcare provider before starting any new supplement.
Is OmneDiem DAO vegan?
No. OmneDiem currently uses porcine-derived DAO (DAOgest®). We plan to offer a plant-based DAO once a stable, active, research-supported source is available.
Related resources
- Product Histamine Digest vs. PureMAX 30,000 or 40,000 HDU of DAOgest® per capsule. See which strength fits your meals.*
- Product Histamine Complete DAO plus quercetin, bromelain, vitamin C, and stinging nettle for seasonal and dietary histamine support.*
- Article DAO: The Enzyme at the Center of the Dietary Histamine Conversation A closer look at what DAO is, how it works in digestion, and why it matters for histamine from food.*
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any new supplement, especially if you are pregnant, nursing, taking medication, or have a medical condition.