Tauroursodeoxycholic Acid

specialtybile acid

At a glance

Best for
investigational use in cholestatic liver disease and ALS; not a routine supplement
Typical dose
500–1500 mg/day, divided with meals
Time to effect
Weeks to months
Main caution
Contraindicated in complete biliary obstruction; loose stools are common
Evidence strength: Moderate for ALS (combination trial); limited for liver and metabolic uses

What is it

Tauroursodeoxycholic acid (TUDCA) is the taurine-conjugated form of ursodeoxycholic acid (UDCA), a naturally occurring hydrophilic bile acid found in small amounts in human bile and historically isolated from bear bile in traditional East Asian medicine. Chemically (C26H45NO6S), it behaves as a chemical chaperone that stabilises protein folding in the endoplasmic reticulum, reducing ER stress and the unfolded protein response, while also exerting anti-apoptotic effects via inhibition of the mitochondrial permeability transition and Bax translocation. In the liver, TUDCA expands the hydrophilic bile-acid pool and competitively displaces cytotoxic hydrophobic bile acids (such as deoxycholic and chenodeoxycholic acid) from hepatocyte membranes, which underlies its hepatoprotective and choleretic activity.

Is it worth it for you?

Worth considering if…

  • You are exploring it under medical care for cholestatic liver disease or ALS
  • You separate it from bile-acid sequestrants and antacids
  • You tolerate possible loose stools

Probably skip if…

  • You have complete biliary obstruction or acute cholecystitis
  • You expect proven neuroprotective or anti-aging benefits
  • You are pregnant or breastfeeding without supervision

Evidence at a glance

GoalEvidenceEffectBest fitTime
amyotrophic lateral sclerosis (ALS)LimitedSlowed functional decline in a combination trialpeople with ALS, under specialist careMonths

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

amyotrophic lateral sclerosis (ALS)

Disease adjunct
Limited

TUDCA acts as a chemical chaperone that reduces ER stress and apoptosis, and a randomized trial of sodium phenylbutyrate plus TUDCA slowed functional decline in ALS, though a later larger phase 3 trial of that combination did not confirm benefit. Because the positive data come from a combination product, the independent effect of TUDCA is uncertain. It remains investigational and specialist-directed.

Effect size: Slowed functional decline in a combination trial
Time to effect: Months
Best fit: people with ALS, under specialist care

Bottom line: TUDCA, in a phenylbutyrate combination, showed promise in ALS but later trials were not confirmatory.

Evidence is mixed

An earlier combination trial slowed ALS decline, but a larger phase 3 trial of the same combination failed to confirm benefit, and TUDCA's solo effect is unclear.

How to take it

Typical dose
500–1500 mg/day
Higher studied dose
Up to ~1750 mg/day in clinical trials for ALS and cholestatic disease
Timing
Divided into 2–3 doses with meals
With food
Take with meals
Split dosing
2–3 divided doses across the day
How long to try
Weeks to months, under medical guidance

What to track

  • liver enzymes and bilirubin where relevant
  • stool consistency
  • the targeted clinical endpoint

Safety

Common side effects

loose stools or diarrhea (dose-related)

Who should avoid it

  • people with complete biliary obstruction
  • those with acute cholecystitis or radiopaque gallstones without supervision

Pregnancy & breastfeeding

Supplemental TUDCA is not recommended in pregnancy or breastfeeding outside medical supervision.

Interactions

bile-acid sequestrants (cholestyramine, colestipol, colesevelam)Moderate

bind TUDCA in the gut and reduce absorption; separate by several hours

aluminium-containing antacidsModerate

impair TUDCA absorption

Choosing a product

Look for

  • stated TUDCA content and purity
  • third-party tested
  • free of undeclared UDCA

Be skeptical of

  • liver detox cure claims
  • guaranteed neuroprotection
  • anti-aging or longevity hype

References by claim

amyotrophic lateral sclerosis (ALS)

  • Elia et al., 2016PMC (2016) link
  • Lombardo et al., 2023PMC (2023) link

Track Tauroursodeoxycholic Acid with Pilora

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Evidence-based·Last reviewed May 30, 2026·Evidence current as of May 30, 2026·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.