TUDCA_Dosage, benefits & legal status
Also known as tauroursodeoxycholic acid, taurursodiol, ursodoxicoltaurine, Tudcabil
A bile acid sold for liver support, with an approval history worth reading.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is TUDCA?
Plain language first. The technical label stays, but it never stands alone.Overview
It helps bile flow and takes strain off liver cells, which is why people take it alongside things that are hard on the liver.
TUDCA is tauroursodeoxycholic acid, the taurine conjugate of ursodeoxycholic acid, a water-loving bile acid that reduces endoplasmic reticulum stress and blocks the mitochondrial pathway to cell death.
What it's used for
An oral bile acid taken as on-cycle liver support, and studied for a much wider set of conditions than it is approved for.
How does TUDCA work?
What it does in the body, and where.TUDCA is a bile acid the body already makes, in small amounts.
- 01It shifts the bile acid pool toward the gentler formsBile acids sit on a scale from water-loving to fat-loving. The fat-loving ones damage cell membranes. TUDCA is at the water-loving end.
- 02It reduces stress in the endoplasmic reticulumThis is the part of the cell that folds proteins. When it backs up, the cell starts a self-destruct sequence. TUDCA acts as a chemical chaperone and eases that backlog.
- 03It interferes with the mitochondrial route to cell deathThat mechanism is behind the interest in neurons and retinal cells, not only liver cells.
- 04None of that is the same as proof it protects a healthy liverThe human data comes from people with liver disease. Whether it does anything measurable for someone taking an oral compound that raises liver enzymes has not been tested.
A schematic of the compound's mechanism, not a diagnostic image.
What else is it used for?
Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
- Cholestatic liver disease and cholesterol gallstones, where it is a licensed medicine in parts of EuropeClinical use
- ALS, as half of a combination product that was approved and then withdrawnInvestigational
- Insulin sensitivity and metabolic healthEarly research
- Protecting retinal cells and neurons under stressEarly research
- Liver support alongside oral compounds that raise liver enzymesResearch only
The published record
Papers and trials about TUDCA
215 papers tagged human · 107 not reviews or lab · 10 clinical trial publications
44 registered trials · 9 with posted results
Furthest stage reached: Approved outside the US, Italy, Turkey
Counted from Europe PMC indexing, not read by a person; a human tag can land on reviews, commentary or lab papers; clinical trial publications is the narrower count. 493 papers and 44 trials indexed in detail.
At a glance
Four things to know about TUDCA
Evidence
Supplement
Category
Longevity and energy
Common vial
Varies
Half-life
Not a useful figure here
How much, and do you cycle it?
The range, and whether you take breaks.500 up to 2,000 mg per day, daily, often split into two doses. Continuous in the trials Trial dose
Human trials dose it daily for months without a planned break. The on-and-off use tied to an oral cycle is a community pattern, and no study has looked at whether it matters.
Not a useful figure hereNo figure
TUDCA joins a bile acid pool the body recycles through the gut and liver many times a day, so a plasma half-life does not describe how long it is doing anything. Trials dose it twice a day for that reason rather than because of a measured clearance figure.
You can compare this against the whole library to see where it sits.
What does it cost?
Typical dose and cost, in plain numbers.TUDCA is not injected
It is taken by mouth (oral). Supplement capsules are usually 250 or 500 mg and the common self-directed range is 500 to 1,000 mg a day. Human trials have gone much higher: the ALS and multiple sclerosis trials used 1 g twice daily, so 2,000 mg a day. There is no US label to check any of this against.
TUDCA starts at $59.00 across 1 vendor.
1 listing, last read Sep 28, 2026. Shipping and card fees are not included.
How do you store it?
Before mixing, and after.Room temperature. Cool, dry, out of light.
TUDCA is taken as a pill or capsule. Keep it in its original container at room temperature, away from heat, humidity, and direct sun. No fridge or mixing needed. Check the expiration date on the bottle.
What are the side effects and cautions?
Known cautions and warnings for this compound.Who should avoid it
- Complete biliary obstruction, where increasing bile flow is the wrong direction
- Pregnancy and breastfeeding, on the basis of absent data rather than known harm
- Any existing liver disease, which needs a diagnosis rather than a supplement
Stop and get help
- Yellowing of the skin or eyes, dark urine or pale stools
- Severe or persistent right-sided abdominal pain
- Diarrhea severe enough to cause dehydration
- Signs of an allergic reaction such as face or throat swelling, hives, or trouble breathing
Common effects
- Diarrhea or loose stools
- Mild stomach upset
- Nausea, usually settling with food
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is TUDCA approved?
And where the numbers on this page come from.Not as a medicine. TUDCA is sold without a prescription as a supplement, which is a different thing from being approved as a drug. It is approved in Italy and Turkey, but not in the United States.
- Approval statusSupplementSold without a prescription as a dietary supplement. The FDA does not approve supplements before they are sold, and being easy to buy says nothing about whether it works.
- RouteBy mouth (oral)
- Checked22 September 2026
- Approved outside the USItaly, Turkey: Approved in Italy and Turkey for cholesterol gallstones, sold in Italy as Tudcabil and exported as Taurolite, and used in Europe for chronic cholestatic liver disease since 1991. Not approved in the US.This does not change the United States position above.
- DoseFrom published human studies. Not approved by a regulator for this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- Sources
What has happened recently
Sold in the US as a dietary supplement, with no FDA approval for any use on its own. The molecule does have an approval history, and it is not the one vendors describe. Under the name taurursodiol it was one half of Relyvrio, a fixed combination with sodium phenylbutyrate that the FDA approved on 29 September 2022 for ALS on the strength of a single phase 2 trial. The confirmatory phase 3 trial, PHOENIX, missed both its primary and its secondary endpoints. The company reported that to the FDA on 30 April 2024, stopped marketing on 31 October 2024, and the approval was formally withdrawn on 29 August 2025. That approval belonged to a two-ingredient product and to one disease, and it no longer exists.
You can compare this against the whole library, or read how to check a seller.
What else is like TUDCA?
Others in Longevity and energy, side by side.If you're weighing TUDCA, it's worth reading GDF-11, Nicotinamide Riboside (NR), and P110 in the same class.
A bile acid sold for liver support, with an approval history worth reading.
- Dose
- 500 up to 2,000 mg per day
- How often
- Daily, often split into two doses
The young blood rejuvenation protein, and the field that spent a decade arguing about it.
- Dose
- Research only
- How often
- Not established
The NAD+ precursor that kept its paperwork in order.
- Dose
- 300 up to 1,000 mg per day
- How often
- Daily
A research peptide that blocks one route to mitochondrial fragmentation, tested only in cells and animals.
- Dose
- No human dose; 1.5 to 3 mg/kg/day by continuous pump in mice
- How often
- Continuous infusion in animals
Guides for this compound
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
- How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.
- How to Vet a Peptide Vendor
Independent COAs, HPLC purity, and the red flags that mean walk away.
Sources
- Federal Register, withdrawal of approval of the Relyvrio new drug application(2025)Approval dates, the PHOENIX result, and the formal withdrawal on 29 August 2025.
- Trial protocol for TUDCA in ulcerative colitis, ClinicalTrials.gov(2019)TUDCA has been licensed in Europe for gallstones and chronic cholestatic liver disease since 1991.
- Kusaczuk, Cells, review of TUDCA molecular and cellular effects(2019)Chaperone activity, ER stress reduction, and the relationship to the approved parent drug UDCA.
Beyond these, 537 records are indexed. Browse the records