Short answer
TUDCA and dihydromyricetin (DHM) turn up on the same shortlists, but they are not two versions of one thing. TUDCA is a bile acid — the taurine conjugate of ursodeoxycholic acid — and is almost always supplied as its sodium salt. DHM, also called ampelopsin, is a dihydroflavonol extracted from a plant. That difference decides nearly everything downstream: TUDCA raises an origin question and an assay-basis question and is aggressively bitter, while DHM raises a botanical-source question and an oxidation question and is poorly water-soluble. You are not choosing the better molecule. You are choosing which documentation burden and which formulation constraint your product can absorb.
This page compares raw-material forms and how they behave in manufacturing. It does not compare health outcomes, and nothing here is a claim about what either material does in the body.
TUDCA vs DHM at a glance
| Property | TUDCA | DHM (dihydromyricetin) |
|---|---|---|
| Compound class | Bile acid; taurine conjugate of ursodeoxycholic acid | Dihydroflavonol (flavonoid) |
| Other names seen on spec sheets | Tauroursodeoxycholic acid; sodium tauroursodeoxycholate | Ampelopsin; vine tea extract; DHM |
| CAS (verify on the COA) | 14605-22-2 free acid; 35807-85-3 sodium salt | 27200-12-0 |
| Molecular weight | ≈499.7 free acid; ≈521.7 sodium salt | ≈320.3 |
| Usual commercial grade | 98% min, most often as the sodium salt | 98% min aglycone, or a standardised extract at a lower percentage |
| Origin | Semi-synthetic from ursodeoxycholic acid; UDCA itself may be bile-derived or synthetic | Botanical extract, most commonly Ampelopsis grossedentata; sometimes Hovenia dulcis |
| Animal-origin question | Yes — must be answered in writing | No |
| Water solubility | Sodium salt dissolves readily; free acid does not | Poorly soluble |
| Taste | Intensely bitter and persistent | Bitter and astringent, milder than TUDCA |
| Colour | White to off-white | Off-white to pale yellow |
| Moisture behaviour | Hygroscopic — specify loss on drying and barrier packaging | Low to moderate |
| UV chromophore for assay | Weak — ELSD, charged-aerosol or LC-MS typical | Strong — routine HPLC-UV |
| Impurity neighbours to ask about | Ursodeoxycholic, taurocholic and taurochenodeoxycholic acid | Residual solvents, other flavonoids, species authentication |
| Thermal behaviour | Salt form has no sharp melting point; confirm thermal data on the spec | Reported around 245 °C; confirm on the COA |
| Dominant format constraint | Taste masking, then moisture | Solubilisation, then oxidation control |
| Best-fit formats as supplied | Capsule, tablet, coated or encapsulated grade | Capsule, tablet, deposited gummy, stick pack |
| Vegan / vegetarian position | Only if a synthetic route is confirmed in writing | Plant-sourced by definition |
Choose TUDCA if…
- The format is a capsule or a coated tablet and the consumer never tastes the active.
- Your QA and regulatory reviewers are prepared to receive and file an origin declaration, and a TSE/BSE statement with country of origin if any step is bile-derived.
- The SKU does not need a vegan, vegetarian, halal or kosher position, or you have confirmed a synthetic route in writing before the brief is locked.
- You need the raw material itself to dissolve — the sodium salt does, and the free acid does not.
Choose DHM if…
- The SKU has to be plant-sourced. DHM removes the animal-origin conversation entirely.
- You want a single well-defined aglycone with an assay any contract lab can run on the HPLC-UV it already owns.
- The format can carry a poorly soluble powder — capsule, tablet, deposited gummy — or you have budgeted for a solubilised grade.
- You are ready to specify species and plant part, because “DHM” and “Hovenia dulcis extract” are not the same purchase.
Ask for a solubilised or co-processed grade if…
- The finished format is a clear beverage, a fast-dissolve stick pack or an effervescent. Neat DHM will not go into a clear system, and neat TUDCA will taste like exactly what it is.
- You need to remove bitterness rather than out-sweeten it. At TUDCA’s intensity, coating and encapsulation move the problem; flavour systems generally do not solve it.
Formulation notes
The assay basis is different for each, and it is where price comparisons go wrong
TUDCA’s trap is the salt. Most commercial “TUDCA 98%” is sodium tauroursodeoxycholate, and the sodium salt is heavier than the free acid — roughly 521.7 against 499.7. A 98% sodium-salt material is therefore about 93.9% on a free-acid basis. Two quotes that both say “98%” can differ by several percent of actual acid before anyone has mentioned price. Ask which basis the number is on, and require the answer on the specification rather than in an email.
DHM’s trap is the source. A 98% material is an aglycone and needs no conversion, but a “vine tea extract” or a “Hovenia dulcis extract” may be standardised anywhere from a few percent to 98% DHM, and Hovenia-sourced material generally carries far less than Ampelopsis grossedentata. A price per kilogram means nothing until you know the species, the plant part and the percentage with the method behind it.
This is the fifth version of the same trap this site has run into: quercetin’s dihydrate water, PQQ’s disodium salt, pterostilbene’s glucoside, apigenin’s glycosides, and now TUDCA’s sodium. Whenever a material can be sold as a salt, a hydrate or a glycoside, the assay basis is the first question, not a footnote.
Origin documentation is the item most TUDCA spec sheets leave out
TUDCA is made from ursodeoxycholic acid, and UDCA reaches the market by more than one route — historically from bovine or ovine bile, and also by chemical synthesis from cholic acid and related sterol starting materials. The finished material looks the same on a chromatogram either way, but the two routes are not the same purchase for a US brand. A bile-derived route puts an animal-origin declaration, a country-of-origin statement and a TSE/BSE risk statement into your file, and it closes the door on a vegan or vegetarian position. Get the route in writing before label copy is drafted, not after. DHM has no equivalent question: it is a plant extract, and the question there is which plant.
The detector matters for TUDCA, and it is worth asking about by name
Bile acids have no strong UV-absorbing group. An assay run on UV alone at a low wavelength is a noisy measurement, which is why TUDCA is typically quantified by HPLC with evaporative light scattering or charged-aerosol detection, or by LC-MS. Two practical consequences follow. Ask which detector produced the number on the COA, and ask which related bile acids the method actually separates — ursodeoxycholic, taurocholic and taurochenodeoxycholic acid are the neighbours that matter. DHM is a flavonoid with a strong chromophore and can be run on the routine HPLC-UV any contract lab already owns, which makes independent verification cheaper and faster.
DHM’s B-ring is a pyrogallol, so oxidation control is not optional
Dihydromyricetin carries three adjacent hydroxyls on its B-ring — a pyrogallol. Read across the flavonoids compared elsewhere on this site and the ladder is clear: apigenin’s B-ring has one hydroxyl, luteolin’s has two adjacent ones and is a catechol, DHM’s has three. More adjacent hydroxyls means more readily oxidised, more sensitive to alkaline pH and more prone to colour drift over shelf life. In practice: hold the system on the acid side of neutral wherever the format allows it, control headspace oxygen and moisture, and run the stability study on the real matrix rather than on the powder.
Bitterness is TUDCA’s real constraint, and it is a hard one
Bile acids taste the way bile acids taste. This is not a taste-masking challenge on the same scale as a bitter botanical — it is the reason TUDCA is overwhelmingly presented in capsules and coated tablets rather than in chewables, gummies or beverages. If a brief asks for TUDCA in a flavoured format, the honest first answer is a coated or encapsulated grade plus a real sensory panel, not a bigger sweetener system. DHM is bitter and astringent too, but it sits inside the range a normal flavour system can work with.
Moisture is the quiet one
TUDCA is hygroscopic. On a capsule line that shows up as flow and fill-weight variation; in a stick pack or a gummy it shows up as caking or texture change late in shelf life. Specify loss on drying, decide the packaging barrier before the stability study rather than after it, and keep the drum closed on the floor.
Documentation and how to verify
Ask for the same core package for both materials, then add the items that are specific to each.
- Both: full specification, a batch-specific COA with the assay method and detector named, identity confirmation, residual solvents, heavy metals, microbiology, allergen statement, GMO statement, and stability data on the form you are actually buying.
- TUDCA only: the assay basis — free acid or sodium salt — stated on the specification, the manufacturing route, an origin declaration, and country of origin plus a TSE/BSE statement if any step is bile-derived.
- DHM only: botanical species and plant part, extraction solvent, the standardisation percentage and the method behind it, and species authentication where the label depends on it.
Verify CAS numbers and molecular weights against the batch documentation rather than against any web page, including this one. Our facility and certification position is set out on quality and certifications, and the general method is in how to verify a supplier COA.
What we do not claim
This page is about raw materials, not outcomes. We make no claim that TUDCA or dihydromyricetin treats, cures, prevents or diagnoses any disease, and no claim about what either material does in the body. Published research exists on both compounds. It is not our data and it is not a supplier claim, so it is not summarised here as though it were. Whether either material is suitable for a given product, population or claim position is a determination for the brand and its regulatory reviewer. The numbers on this page are chemistry — molecular weights, the salt-to-acid conversion, CAS references — independently verifiable, and they should still be checked against the batch documentation.
Related guides and product routes
- TUDCA vs milk thistle (silymarin) — the other fork in this category, a bile acid against a standardised botanical.
- Apigenin vs luteolin — where the hydroxyl-count reasoning above comes from.
- Category overview for this ingredient group.
- How to verify a supplier COA.
- All ingredient selection guides.
- Product routes: Tauroursodeoxycholic acid (TUDCA) and Dihydromyricetin 98%.
Frequently asked questions
Are TUDCA and DHM the same kind of ingredient?
No. TUDCA is a bile acid, the taurine conjugate of ursodeoxycholic acid, and is usually supplied as a sodium salt. Dihydromyricetin is a plant flavonoid, a dihydroflavonol also called ampelopsin. They belong to different chemical families, are made by different routes, and carry different documentation requirements.
Why does 98% TUDCA not always mean the same thing?
Because most commercial TUDCA is the sodium salt, which is heavier than the free acid — about 521.7 against 499.7. A 98% sodium-salt material is roughly 93.9% on a free-acid basis. Ask which basis the assay is stated on and require it on the specification.
Is TUDCA animal-derived?
It depends on the manufacturing route, which is exactly why it has to be asked. TUDCA is made from ursodeoxycholic acid, and UDCA may be bile-derived or synthetic. Request a written origin declaration, and if any step is bile-derived, ask for country of origin and a TSE/BSE statement.
What is the difference between DHM and Hovenia dulcis extract?
They are not interchangeable specifications. High-purity dihydromyricetin is most commonly produced from Ampelopsis grossedentata, or vine tea. Hovenia dulcis extracts generally carry much less DHM and are sold on a different basis. Specify species, plant part and the standardised percentage with its method.
Can either be used in a clear beverage or a fast-dissolve stick pack?
TUDCA’s sodium salt dissolves readily, but bitterness is the limiting factor in any format the consumer tastes. DHM is poorly water-soluble and will not go into a clear system as a neat powder. For either, ask for a solubilised or co-processed grade and start the sensory work early.
Which documents should we request before sampling?
Specification, a batch-specific COA with the assay method and detector named, identity, residual solvents, heavy metals, microbiology, allergen and GMO statements, and stability data on the form being purchased. Add the assay basis and an origin declaration for TUDCA, and species, plant part and standardisation method for DHM.
Request a sample, COA or specification
Tell us the format, the target inclusion level and the claim lane you are working in, and we will send the specification and a batch COA for the grade that actually fits — including the assay basis for TUDCA and the botanical source for DHM.
Request a sample, COA or specification
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