TUDCA
Research Guide

What is TUDCA?

TUDCA (tauroursodeoxycholic acid) is a bile acid: ursodeoxycholic acid (UDCA) joined to taurine (2-aminoethanesulfonic acid) by an amide bond (PubChem CID 9848818). Its drug names are taurursodiol and ursodoxicoltaurine. Bear bile is a natural source. In gallbladder bile from six bear species, all bile acids were conjugated with taurine, and UDCA averaged 34% of biliary bile acids in American black bears (Hagey et al., 1993).

UDCA on its own is ursodiol, a prescription drug the FDA first approved in 1987 (Drugs@FDA). Disguised Alpha sells TUDCA only in one product, a capsule blend with S-acetyl glutathione: 250MG TUDCA and 100MG S-acetyl glutathione per capsule, 60 capsules per bottle, for laboratory research use only. Nothing on this page is guidance for use in people.

TUDCA reference data

Strengths, count, format and storage are from the product page, which lists no formula or weight. Those values and the synonyms are from PubChem (CIDs 9848818 and 9894372), and the TUDCA values are for the free acid. Confirm from the certificate whether the capsules hold the free acid or a salt.

See it beside the other compounds on this site in the peptide molecular weight reference table.

What the research covers

TUDCA research falls into five areas, each with its model named. Most findings come from cells and rodents. Human data come from a few trials, given here as research history.

ER stress and the unfolded protein response

In Huh7 cells, a human liver-derived line, thapsigargin raised intracellular calcium, induced the ER chaperone BiP/GRP78 and activated caspase-12 before apoptosis. TUDCA abolished the thapsigargin-induced ER stress markers, reduced calcium efflux, BiP/GRP78 induction and caspase-12 activation, and inhibited effector caspases and apoptosis (Xie et al., 2002).

In a test-tube assay, TUDCA limited stress-induced albumin aggregation better than 4-phenylbutyric acid (PBA). In HepG2 cells, both dampened the PERK-eIF2alpha-ATF4-CHOP arm of the unfolded protein response triggered by tunicamycin; TUDCA alone also activated PERK and, unlike PBA, did not lower cell viability (Uppala et al., 2017). Models: human hepatoma cells and purified protein.

Metabolic ER stress in mice and one human trial

TUDCA and PBA reduced ER stress in cultured cells and in obese, diabetic mice, where they normalized hyperglycemia, restored systemic insulin sensitivity and enhanced insulin action in liver, muscle and adipose tissue; the authors called both chemical chaperones (Ozcan et al., 2006).

In a later trial, 20 adults with obesity were randomized to 4 weeks of TUDCA or placebo and studied with a hyperinsulinemic-euglycemic clamp and biopsies. Liver and muscle insulin sensitivity rose by about 30% with TUDCA only, but ER stress markers in muscle and adipose tissue did not change in either group (Kars et al., 2010). Models: cells, mice and a small randomized human trial.

Retinal degeneration models

In rd10 mice, which carry a rod phosphodiesterase mutation, and in mice exposed to damaging bright light, systemic TUDCA slowed retinal degeneration by every measure reported: larger ERG a-wave and b-wave amplitudes, thicker outer nuclear layers, more photoreceptors and fewer apoptotic cells (Boatright et al., 2006). At postnatal day 30, TUDCA-exposed rd10 mice had about twofold larger ERG responses and five times as many photoreceptors as vehicle controls, and TUDCA did not alter wild-type retinas (Phillips et al., 2008). Models: mice only.

Apoptosis in brain injury and neurodegeneration models

In rats with collagenase-induced intracerebral hemorrhage, TUDCA given before or up to 6 hours after injury cut lesion volume at 2 days by up to 50%, roughly halved apoptosis around the hematoma and activated Akt survival signaling (Rodrigues et al., 2003). In R6/2 mice, a Huntington's disease model, systemic TUDCA from 6 weeks of age reduced striatal atrophy and apoptosis, left fewer and smaller huntingtin inclusions and lessened locomotor and sensorimotor deficits (Keene et al., 2002).

In an MPTP mouse model of Parkinson's disease, TUDCA given beforehand protected dopaminergic neurons and prevented JNK phosphorylation (Castro-Caldas et al., 2012). In APP/PS1 mice, an Alzheimer's disease model, six months of TUDCA-supplemented chow prevented the memory defects seen at 8 months and reduced hippocampal and prefrontal amyloid (Lo et al., 2013). Models: rats and mice only.

ALS trials and the sodium phenylbutyrate-taurursodiol combination

In a pilot trial, 34 people with amyotrophic lateral sclerosis (ALS) on riluzole were randomized to TUDCA or placebo for 54 weeks after a 3-month lead-in. Responders, with at least 15% slower decline on the ALS Functional Rating Scale-Revised (ALSFRS-R) than in the lead-in, were 87% of the TUDCA group and 43% of the placebo group; adverse events did not differ (Elia et al., 2016). The European TUDCA-ALS phase 3 trial closed recruitment in December 2021 (Lombardo et al., 2023), but as of October 2026 PubMed holds no peer-reviewed report of its outcome.

In the phase 2 CENTAUR trial, 137 people with ALS were randomized 2:1 to sodium phenylbutyrate-taurursodiol or placebo; ALSFRS-R fell by 1.24 versus 1.66 points per month over 24 weeks, and secondary outcomes did not differ significantly (Paganoni et al., 2020). Per the FDA's Federal Register notice, the agency approved the combination as Relyvrio for ALS in adults on September 29, 2022.

Its 48-week phase 3 trial, PHOENIX, did not meet its prespecified primary and secondary endpoints. The company planned to stop marketing it as of October 31, 2024, then asked for withdrawal at the FDA's request, and approval was withdrawn as of August 29, 2025. Models: randomized human trials and the FDA record.

Key studies

1. Keene CD, et al. "Tauroursodeoxycholic acid, a bile acid, is neuroprotective in a transgenic animal model of Huntington's disease." Proc Natl Acad Sci U S A. 2002. PMID 12149470. DOI 10.1073/pnas.162362299. R6/2 transgenic mice.
2. Xie Q, et al. "Effect of tauroursodeoxycholic acid on endoplasmic reticulum stress-induced caspase-12 activation." Hepatology. 2002. PMID 12198651. DOI 10.1053/jhep.2002.35441. Huh7 cells.
3. Ozcan U, et al. "Chemical chaperones reduce ER stress and restore glucose homeostasis in a mouse model of type 2 diabetes." Science. 2006. PMID 16931765. DOI 10.1126/science.1128294. Obese, diabetic mice.
4. Boatright JH, et al. "Tool from ancient pharmacopoeia prevents vision loss." Mol Vis. 2006. PMID 17213800. rd10 and light-damaged mouse retina.
5. Uppala JK, et al. "Chemical chaperone, TUDCA unlike PBA, mitigates protein aggregation efficiently and resists ER and non-ER stress induced HepG2 cell death." Sci Rep. 2017. PMID 28630443. DOI 10.1038/s41598-017-03940-1. Purified protein and HepG2 cells.
6. Paganoni S, et al. "Trial of Sodium Phenylbutyrate-Taurursodiol for Amyotrophic Lateral Sclerosis." N Engl J Med. 2020. PMID 32877582. DOI 10.1056/NEJMoa1916945. Phase 2 CENTAUR trial, 137 people with ALS.

Handling and storage of TUDCA / S-acetyl glutathione capsules

General laboratory practice for this material:

• Store the sealed capsules at 15 to 25°C in the original sealed container, away from moisture and direct light (product page).
• The container is a sealed plastic or glass bottle or a resealable pouch, depending on the batch; close it fully after each opening.
• Each capsule holds both compounds, so it cannot supply a TUDCA-only or S-acetyl glutathione-only arm.
• Record the lot number. The certificate summary on the product page lists appearance and HPLC identity, so check what your lot's certificate reports before quantitative work.
• For identity checks, compare data with C₂₆H₄₅NO₆S, 499.7 g/mol (TUDCA free acid) and C₁₂H₁₉N₃O₇S, 349.36 g/mol (S-acetyl glutathione).

Frequently asked questions

What is TUDCA?

TUDCA is tauroursodeoxycholic acid, the taurine conjugate of the bile acid UDCA (PubChem CID 9848818). It occurs naturally in bear bile (Hagey et al., 1993), and labs often study it as a chemical chaperone that lowers ER stress.

Is TUDCA the same as UDCA or ursodiol?

No. UDCA is the unconjugated bile acid (PubChem CID 31401), and ursodiol is its drug name; TUDCA is UDCA joined to taurine. The FDA approved ursodiol capsules, now labeled for certain gallbladder stones, in 1987 (Drugs@FDA) and ursodiol tablets, labeled for primary biliary cholangitis, in 1997 (Drugs@FDA). Taurursodiol appears in Drugs@FDA only in the discontinued sodium phenylbutyrate-taurursodiol product.

What does TUDCA research show about ER stress?

In cells and mice, TUDCA lowered ER stress and unfolded protein response markers such as BiP/GRP78, caspase-12 and PERK-eIF2alpha-ATF4-CHOP signaling (Xie et al., 2002; Uppala et al., 2017; Ozcan et al., 2006). In the one human study that measured them, ER stress markers in muscle and adipose tissue did not change (Kars et al., 2010).

Has TUDCA been tested in people?

Yes, in small trials, given here as research history: a 20-person insulin sensitivity study (Kars et al., 2010) and a 34-person ALS pilot (Elia et al., 2016). The TUDCA-ALS phase 3 trial has a published analysis plan (Lombardo et al., 2023) but no peer-reviewed outcome in PubMed as of October 2026. TUDCA alone is not an FDA-approved drug.

What is S-acetyl glutathione?

It is glutathione (gamma-L-glutamyl-L-cysteinyl-glycine) with an acetyl group on the cysteine sulfur, which turns the free thiol into a thioester (PubChem CID 9894372). It is the second ingredient in the capsule blend. The glutathione research guide covers the glutathione literature.

Where can researchers buy TUDCA?

Disguised Alpha sells TUDCA only as TUDCA / S-Acetyl Glutathione: capsules with 250MG TUDCA and 100MG S-acetyl glutathione each, 60 per bottle, for laboratory research, with each lot's certificate on the product page.

Related compounds and guides

• Glutathione research guide
• NAC research guide
• NAC vs glutathione: research comparison
• Methylene blue research guide
• COA portal: every published certificate, by lot

This product is for research use only. It has not been evaluated for safety or effectiveness in humans. Not for human consumption. All products are intended for laboratory research purposes only.

Research basics

• What are peptides?
• What is a certificate of analysis (COA)?
• What does lyophilized mean?
• What are peptide bioregulators?
• Peptide calculator: concentration and volume
• Peptide molecular weight calculator