TUDCA research in people

• 27published studies in people
• 1study after gallbladder removal
• 12 mothe longest digestive or liver trial
• 0studies of TUDCA as a fatty liver treatment

What the studies found, and how much research stands behind it

The research grade measures how much evidence there is and how firm it is, not whether TUDCA works. A low grade means “not yet confirmed”, not “shown not to work”.

• Liver blood tests in primary biliary cholangitisFound: Results similar to UDCA, the standard treatmentOne trial of 199 people over 24 weeks, plus smaller ones; laboratory resultsResearchModerate
• Preventing or dissolving cholesterol gallstonesFound: Less cholesterol in bile; a licensed use in Italy and TurkeySmall trials; UDCA did better in the one head-to-head trialResearchEarly
• Liver enzymes in chronic hepatitis CFound: Lower liver enzymes than placeboOne placebo-controlled trial; no effect on the virusResearchEarly
• Liver insulin sensitivity in obesityFound: Better insulin sensitivity than placeboOne four-week trial in 20 peopleResearchEarly
• Liver transplant; liver problems in infants on IV nutritionFound: No difference foundTwo small controlled trialsResearchEarly
• Indigestion after gallbladder removalFound: Faster relief in the first monthOne study of 203 people, without a placebo; not yet confirmedResearchPreliminary
• Liver tests in cirrhosisFound: Better liver testsTwo very small studies, without a proper comparison between groupsResearchPreliminary
• Ulcerative colitisFound: Lower disease scoresOne study without a control group, not yet peer reviewedResearchPreliminary
• Fatty liver, bloating, IBS, bile reflux, diarrheaFound: Not yet testedNo published study in people has tested TUDCA as a treatmentResearchNot yet studied

• Strong
• Moderate
• Early
• Preliminary
• Not yet studied

Research grades are ours, made on the scale described in “How we did this review”. No use of TUDCA has yet reached “Strong”.

What TUDCA is

Tauroursodeoxycholic acid (TUDCA) is a bile acid: one of the detergent-like molecules your liver makes so that fat can be digested. It is hydrophilic, or water-loving, and it occurs naturally in small amounts in human bile. Together with its close relative UDCA (ursodeoxycholic acid), it makes up about 2% of the body's bile acids.^[10]

The two are closely linked. TUDCA is UDCA with the amino acid taurine attached, and the body moves between them: after a dose of TUDCA, much of what appears in the blood is UDCA, and in bile some of it is re-attached to glycine instead of taurine.^[7,11,12] That is why this review compares TUDCA with UDCA throughout. It is also why research on UDCA, a well-studied prescription medicine, cannot simply be borrowed for TUDCA. Where the two have been tested side by side, the results are reported below.

Where it is a medicine, and where it is a supplement

A trial registration says TUDCA is also approved in China for cholesterol gallstones; we could not confirm this with China's regulator.^[16]

What has been studied, and when

Most human research on TUDCA in digestive and liver health was published between 1993 and 2002, much of it in Italy, where TUDCA has been a licensed medicine since 1991. Most studies ran for six months or less, and the longest trial ran for a year. Several of the liver studies come from the same research group in Milan.^{[6,7,17,18,19]} Since 2010 there have been nine more, from China, the US and Italy.

• 10 people
• 50
• 200
• Not stated

Each dot is one study; its size shows how many people took part. The largest are Croce 1993 after gallbladder removal (203 people) and Ma 2016 in primary biliary cholangitis (199 people). Sources: the 27 studies listed in “All 27 studies”.

One more pattern is worth knowing. Of the TUDCA trials registered on ClinicalTrials.gov, roughly two-thirds are outside digestive and liver health: in ALS and other neurological conditions, diabetes and insulin resistance, and heart amyloidosis, among others. Those conditions are outside the scope of this review.^[16]

After gallbladder removal

TUDCA has been studied in people after gallbladder removal in a controlled trial of 203 patients (Croce 1993). It is set out below on the same fields as every other study in this review, followed by our note on how to read it.

Croce 1993

Gallbladder and bile · study appraisal

People

203 adults after gallbladder removal, all with indigestion

Design

Controlled trial

Compared with

No treatment

Randomized

Not stated

Blinded

Not stated

Dose

500 mg/day

Length

Checked at 1, 2 and 3 months

Measured

Indigestion symptoms

Result

Symptoms eased faster on TUDCA, a significant difference at 1 month; at 2 and 3 months symptoms were at a similar level in both groups. Side effects in 2 vs 3 people.

Main limits

No placebo; no symptom scores or p-values in the published summary; indigestion only.

Source: ^[1] Croce E, Golia M, Trignano M, et al. [Rationale for the use of bile salts after cholecystectomy: results of a controlled clinical study using tauroursodeoxycholic acid (TUDCA)]. Ann Ital Chir. 1993;64(5):533-537.

1. Month 1Faster improvementIndigestion eased faster in the TUDCA group, a significant difference.
2. Month 2Similar in both groupsThe untreated group improved too and caught up; symptoms were at a similar level.
3. Month 3Similar in both groupsBoth groups stayed improved, at a similar level.

The published summary reports no symptom scores, so this shows the direction of each result, not its size. Source: Croce 1993.^[1]

Turkey's medicine label lists “biliary dyspepsia with or without cholecystectomy” among TUDCA's uses.^[3] A licence reflects a regulator's judgment, but we grade evidence on the published studies, and we could not find any beyond the Croce study. That is why the research for this use is graded “Preliminary” despite the licence. The same reasoning keeps gallstones at “Early”: the licence is long-standing, but the published trials are small.

Gallstones and bile

Gallstones are TUDCA's licensed medical use, and the reason it was first studied. In many countries, about three in four gallstones are made mainly of cholesterol,^[20] and they form when bile carries more cholesterol than it can keep dissolved. A bile acid that lowers that saturation can, over months, slowly dissolve small, non-calcified stones in a gallbladder that still works.

• It changes bile in the expected direction. In 33 people with cholesterol gallstones, cholesterol saturation fell as the dose rose: from 147% at the start to about 80% at 11 mg per kg a day, after four to six weeks.^[21,22] There was no control group, and the study measured bile chemistry, not whether stones dissolved.
• Against UDCA, it did less well. In the only randomized comparison, 31 people with gallstones took one or the other for six months. UDCA dissolved stones completely more often, eased indigestion more and was better tolerated, though the authors called TUDCA acceptable.^[4]
• Stones calcified at similar rates on TUDCA, UDCA and CDCA, a third bile acid, in a non-randomized comparison of 262 people.^[23]
• It did not change how the gallbladder empties after a single dose, though the resting gallbladder was larger after a month.^[24]
• Two recent Chinese studies add little. One gave TUDCA for only two weeks before surgery and measured bile chemistry; its authors favored a probiotic.^[25] In the other, everyone took TUDCA and the trial tested an acupuncture technique, so TUDCA's own effect was never isolated.^[26]

Liver disease

Most human TUDCA research is in liver disease, and almost all of it measured liver blood tests rather than outcomes such as complications, transplants or survival. Better blood tests are encouraging but do not, on their own, show that a disease is changing course.

Primary biliary cholangitis

Primary biliary cholangitis (PBC) is a long-term autoimmune disease of the small bile ducts in the liver. UDCA is the usual first treatment,^[5] so TUDCA has mostly been compared with UDCA rather than with a placebo. The largest trial is the most informative study in this review:

Ma 2016

Liver disease · study appraisal

People

199 people with primary biliary cholangitis

Design

Randomized, double-blind, non-inferiority

Compared with

UDCA

Randomized

Yes

Blinded

Double-blind

Dose

750 mg/day

Length

24 weeks

Measured

Share whose ALP fell by more than 25%

Result

75.97% on TUDCA vs 80.88% on UDCA (P=0.453). The authors judged it no worse, but reported no confidence interval for their 10% margin. Itching rose on UDCA only. Side effects 44% vs 40%.

Main limits

24 weeks; a laboratory endpoint; 2:1 allocation; partly sponsored by a commercial company.

Source: ^[5] Ma H, Zeng M, Han Y, et al. A multicenter, randomized, double-blind trial comparing the efficacy and safety of TUDCA and UDCA in Chinese patients with primary biliary cholangitis. Medicine (Baltimore). 2016;95(47):e5391.

Smaller studies point the same way. Liver enzymes fell at 500, 1,000 and 1,500 mg a day, with no added benefit from the higher doses.^[18] In 23 people who took each acid in turn for six months, the two did equally well.^[17] One small 1993 trial found UDCA better on one liver test and better tolerated.^[27]

Chronic hepatitis C

In 150 people with hepatitis C, six months of TUDCA lowered liver enzymes compared with placebo (p<0.001). The published summary does not report effects on the virus or on liver biopsies.^[19] When TUDCA was added to interferon, an older antiviral treatment, it made no difference to liver enzymes, the virus or biopsies, though patients needed less interferon to keep their liver enzymes normal.^[28] A Cochrane review of bile acids in viral hepatitis found the same pattern across UDCA and TUDCA trials: lower liver enzymes, no effect on clearing the virus, and a slightly worse inflammation score on liver biopsy.^[29]

Cirrhosis, transplants and infants

• After a liver transplant, 33 people took TUDCA or nothing for a year. Graft function, rejection and survival did not differ.^[30] A Cochrane review of bile acids after transplantation, which included this as its one TUDCA trial among seven, found no clear benefit.^[31]
• In cirrhosis, two very small studies reported better liver tests: one compared 10 people with patients treated the year before, and the other, a randomized trial against UDCA, reported only changes within each group.^[32,33]
• In infants on intravenous nutrition, TUDCA did not prevent the liver problems it was tested against.^[34]

UDCA betterNo clear differenceTUDCA better

• Gallo 1993^[4]Gallstones · Dissolution, symptoms, tolerabilityResult: UDCA better
• Ferri 1993^[27]Primary biliary cholangitis · Liver tests, tolerabilityResult: UDCA better
• Larghi 1997^[17]Primary biliary cholangitis · Liver enzymesResult: no clear difference
• Ma 2016^[5]Primary biliary cholangitis · ALP response (199 people)Result: no clear difference
• Bazzoli 1995^[23]Gallstones (not randomized) · Stones calcifyingResult: no clear difference
• Rudolph 2002^[11]Blocked bile ducts · AbsorptionResult: no clear difference
• Invernizzi 1999^[6]Primary biliary cholangitis · AbsorptionResult: TUDCA better
• Portincasa 1996^[24]Gallstones and healthy volunteers · Gallbladder emptyingResult: no clear difference
• Hardison 1984^[35]Healthy men · Bile acid production, cholesterol absorptionResult: no clear difference
• Pan 2013^[32]Cirrhosis · Liver tests (no comparison reported)Result: not compared

A hollow mark means the study did not compare the two groups directly.

The gut and metabolism

Research on TUDCA in the gut and in metabolism is more recent.

• Ulcerative colitis: in an open-label study of 14 people, of whom 11 could be assessed, the average disease score fell from 9 to 4.5 over six weeks.^[36] There was no randomized or concurrent comparison group, and the results have not yet been peer reviewed. Without a comparison group, some of that improvement could have happened anyway, so this is a reason to run a controlled trial rather than a finding in itself.
• Gut bacteria: one case report of a 92-year-old woman who was also taking antibiotics.^[37]
• Insulin sensitivity: in 20 adults with obesity, four weeks of 1,750 mg a day raised the insulin sensitivity of the liver and muscles by about 30% compared with placebo. Liver fat and liver enzymes did not change.^[38]

We found no published study in people of TUDCA as a treatment for fatty liver disease (NAFLD or MASLD), irritable bowel syndrome, bloating, bile reflux, bile acid diarrhea or pancreatitis. The nearest is the insulin study above: many of its participants had high liver fat, and their liver fat did not change in four weeks.^[38]

Is it absorbed?

Yes. Taken by mouth, TUDCA is absorbed mainly in the last part of the small intestine, the ileum, and enters the bile acid pool.^[39] In people with liver disease, UDCA and its conjugates rose to about a third of the bile acids in bile.^[6,7]

Three doses of TUDCA, people with PBC (Setchell 1996)^[7]

• 500 mg a day34.4%
• 1,000 mg a day32.8%
• 1,500 mg a day41.6%

TUDCA vs UDCA, 750 mg each, people with PBC (Invernizzi 1999)^[6]

• TUDCA32.6%
• UDCA29.2%

TUDCA vs UDCA, equal molar doses, blocked bile ducts (Rudolph 2002)^[11]

• TUDCA54.6%
• UDCA55.2%

Share of bile acids in bile that were UDCA or its conjugates, during treatment. All three studies were in people with liver or bile-duct disease; none was in people without a gallbladder.

Whether TUDCA is absorbed better than UDCA is unsettled: one small study found it was, another found no significant difference.^[6,11] One finding matters for anyone without a gallbladder, and it is a gap: no study has measured how TUDCA is absorbed or handled in people whose gallbladder has been removed. In them, bile flows directly into the gut instead of being stored in the gallbladder,^[40] and that could change how a bile acid behaves.

Safety

Across the trials, TUDCA has been well tolerated. The consistent side effects are mild digestive ones: looser stools or diarrhea, nausea and indigestion.

Doses used in trials

• After gallbladder removal (Croce 1993)500 mg
• Liver trials, 1993–2016500–1,500 mg
• Insulin sensitivity (Kars 2010)1,750 mg
• Ulcerative colitis (Lamm 2025)1,750–2,000 mg
• ALS and multiple sclerosis trials2,000 mg

05001,0001,5002,000mg a day

Shaded: the dose on the Italian medicine label, 250–750 mg a day

Side effects compared with a control group

Ma 2016, PBC, 24 weeks^[5] · Any side effect

• TUDCA44%
• UDCA40%

Elia 2016, ALS, 54 weeks^[8] · Study-related side effects

• TUDCA13.3%
• Placebo21.4%

Ladakis 2025, MS, 16 weeks^[9] · Any side effect

• TUDCA38%
• Placebo33%

Percentages are of people in each group, as reported by each trial. Elia 2016 counted only events the investigators judged related to the study medicine.

• In the largest liver trial, side effects were about as common on TUDCA as on UDCA (44% and 40%), most were judged unrelated to the medicine, and none was serious.^[5]
• In two placebo-controlled trials at 2 g a day, side effects were about as common as on placebo, and mostly digestive.^[8,9] One person in the multiple sclerosis trial was hospitalized with an inflammation of the bile ducts, which the safety board judged unlikely to be related. That person already had abnormalities of the bile ducts, and the authors suggested excluding people with known bile-duct abnormalities from future trials.^[9]
• Two small Italian trials from 1993 found TUDCA less well tolerated than UDCA.^[4,27]
• The longest controlled use is 18 months at 2 g a day, in a trial in ALS.^[41] Its full results have not been published; the investigators described the medicine as well tolerated.^[42]

What we still don't know

All 27 studies

Every study in this review, appraised on the same fields. “Not stated” means the published summary does not say, not that the answer is no. On a phone, scroll the table sideways.

Scroll sideways to see every column →

Study	People	Design	Compared with	Randomized	Blinded	Dose	Length	Measured	Result	Main limits
Gallbladder and bile
Croce 1993[1]	203 adults after gallbladder removal, all with indigestion	Controlled trial	No treatment	Not stated	Not stated	500 mg/day	Checked at 1, 2 and 3 months	Indigestion symptoms	Symptoms eased faster on TUDCA, a significant difference at 1 month; at 2 and 3 months symptoms were at a similar level in both groups. Side effects in 2 vs 3 people.	No placebo; no symptom scores or p-values in the published summary; indigestion only.
Gallo 1993[4]	34 people with gallstones (31 finished)	Randomized trial	UDCA	Yes	Single-blind	10 mg/kg/day	6 months	Stone dissolution, symptoms, tolerability	UDCA dissolved stones completely more often, eased indigestion more (p<0.01) and was better tolerated.	Small; dissolution counts not given in the abstract.
Muraca 1995[21]	33 people with cholesterol gallstones	Dose-ranging study, no control group	None (before vs after)	Not stated	Not stated	3.5–16.6 mg/kg/day	4–6 weeks	Cholesterol saturation of bile	Saturation fell as the dose rose, from 147% at the start to about 80% at 11 mg/kg/day.	No control group; bile chemistry, not stone dissolution; the same group was reported twice.
Bazzoli 1995[23]	262 people on stone-dissolving bile acids, 31 of them on TUDCA	Observational comparison	UDCA, CDCA	No	Not stated	Not stated	Not stated	Stones becoming calcified during treatment	12.9% on TUDCA, 13.2% on UDCA, 8.8% on CDCA; no significant difference.	Not randomized; small TUDCA group; dose not reported.
Portincasa 1996[24]	People with gallstones and healthy volunteers (number not stated)	Single dose, then 1 month	UDCA; placebo (single dose)	Indexed as randomized; method not described	Not stated	10 mg/kg	Single dose; 1 month	Gallbladder emptying on ultrasound	Emptying unchanged; resting gallbladder volume increased after 1 month.	No numbers in the abstract.
Gao 2022[25]	96 people with gallstones before surgery	Randomized trial, four groups of 24	Probiotic; TUDCA plus probiotic; no treatment	Yes	Not stated	5–10 mg/kg/day	2 weeks	Blood lipids and bile chemistry	Some blood and bile measures changed; the authors favored the probiotic.	Two weeks; laboratory measures only; no symptoms recorded.
Duan 2022[26]	70 people with gallstones (63 analyzed)	Randomized trial of an acupuncture technique; everyone also took TUDCA	Sham procedure (both groups on TUDCA)	Yes	Sham-controlled	500 mg/day	8 weeks	Gallbladder emptying, symptoms	Symptoms fell in the TUDCA-only group, but with no group off TUDCA the change cannot be credited to it.	TUDCA itself was not tested.
Liver disease
Ferri 1993[27]	30 people with primary biliary cholangitis (25 finished)	Randomized trial	UDCA	Yes	Not stated	12–15 mg/kg/day	6 months	Liver tests, tolerability	UDCA improved liver tests more (significantly for GGT) and was better tolerated.	Small; no numbers in the abstract.
Panella 1995[43]	5 people with hepatitis C liver disease	Single group, no control	None	No	No	Printed as 10–13 mg/day (probably per kg)	3 months	Liver-cell growth marker, ALT	ALT fell; the liver-cell growth marker rose (p<0.05).	Five people; no control group; dose unclear.
Crosignani 1996[18]	24 people with primary biliary cholangitis	Randomized to three doses	Dose vs dose	Yes	Not stated	500, 1,000 or 1,500 mg/day	6 months	Liver enzymes, bile composition	Liver enzymes fell with every dose, with no difference between doses. Diarrhea was the only side effect.	No placebo or UDCA group.
Larghi 1997[17]	23 people with primary biliary cholangitis	Crossover (everyone took both)	UDCA	Yes (order)	Not stated	500 mg/day	6 months on each	Liver enzymes	Both improved liver enzymes, with no difference between them; no side effects reported.	Small pilot; low dose for both.
Crosignani 1998[19]	150 people with chronic hepatitis C	Randomized, placebo-controlled, several centers	Placebo	Yes	Not stated	500 or 750 mg/day	6 months	Liver enzymes (ALT, AST)	Liver enzymes fell more than on placebo (p<0.001).	Enzymes only; no results on the virus or liver biopsies in the abstract.
Angelico 1999[30]	33 people after a liver transplant	Randomized pilot	No treatment	Yes	No	500 mg/day	12 months	Graft function, rejection, survival	No difference in graft function, rejection or survival (78.6% vs 86.7% at one year, not significant). No dropouts.	Small; unblinded; no placebo.
Caglieris 2000[33]	10 people with cirrhosis awaiting a transplant	Compared with earlier patients	Untreated patients from the year before	No	No	Not stated	Until transplant (under 6 months)	Liver tests, hospital stay	Liver tests fell; shorter hospital stays reported, without figures.	Ten people; historical comparison; dose not reported.
Heubi 2002[34]	52 infants on intravenous nutrition after surgery	Controlled trial	Untreated or placebo	Not stated in the abstract	Not stated	30 mg/kg/day	Up to 120 days	Bilirubin, liver enzymes (prevention of cholestasis)	No difference between the groups.	Infants; a different condition from adult disease.
Hepatology Research 2002[28]	106 people with chronic hepatitis C on interferon	Randomized add-on trial	Interferon alone	Yes	Not stated	10 mg/kg/day	6 months, then 6 months tapering	ALT, the virus, liver biopsy	No difference in normal ALT (44% with TUDCA vs 41% without), the virus or biopsies; a lower interferon dose was needed.	An interferon regimen no longer used.
Pan 2013[32]	23 people with cirrhosis (18 analyzed)	Randomized, double-blind	UDCA	Yes	Double-blind	750 mg/day	6 months	Liver tests, fibrosis markers	Liver tests improved from the start in both groups; fibrosis markers unchanged. No comparison between the groups was reported.	Very small; one in five excluded from the analysis.
Ma 2016[5]	199 people with primary biliary cholangitis	Randomized, double-blind, non-inferiority	UDCA	Yes	Double-blind	750 mg/day	24 weeks	Share whose ALP fell by more than 25%	75.97% on TUDCA vs 80.88% on UDCA (P=0.453). The authors judged it no worse, but reported no confidence interval for their 10% margin. Itching rose on UDCA only. Side effects 44% vs 40%.	24 weeks; a laboratory endpoint; 2:1 allocation; partly sponsored by a commercial company.
Gut
Francini 2024[37]	One 92-year-old woman on tube feeding	Case report	None	No	No	Not stated	Long-term	Gut bacteria	Shifts in some groups of gut bacteria.	One person; antibiotics given at the same time.
Lamm 2025[36]	14 people with ulcerative colitis (13 finished)	Single group, open-label; preprint	None	No	No	1,750–2,000 mg/day	6 weeks	Gut-lining stress markers, disease score	Average Mayo score fell from 9 to 4.5 (11 evaluable).	No randomized or concurrent control group; not yet peer reviewed.
Metabolism
Kars 2010[38]	20 adults with obesity and insulin resistance	Randomized, placebo-controlled	Placebo	Yes	Single-blind	1,750 mg/day	4 weeks	Insulin sensitivity of liver and muscle	Liver and muscle insulin sensitivity rose about 30%. Liver fat and liver enzymes did not change.	Small; four weeks.
Absorption
Hardison 1984[35]	6 healthy men	Each bile acid for a month, then a month off	UDCA; time off treatment	Not stated	Not stated	20 mg/kg/day	1 month	Bile acid production, cholesterol absorption	The body's own bile acid production did not change; cholesterol absorption fell.	Six men; no numbers in the abstract.
Setchell 1996[7]	People with primary biliary cholangitis (number not stated)	Randomized dose groups	Dose vs dose	Yes	Not stated	500, 1,000 or 1,500 mg/day	6 months	Makeup of bile acids in bile	UDCA and its conjugates rose to 34.4%, 32.8% and 41.6% of bile acids.	People with liver disease; likely the same group as Crosignani 1996.
Invernizzi 1999[6]	12 women with primary biliary cholangitis	Crossover	UDCA	Yes	Not stated	750 mg/day	2 months on each	Absorption and breakdown	UDCA and its conjugates made up 32.6% of bile acids on TUDCA vs 29.2% on UDCA (P<.05); less lithocholic acid on TUDCA.	Twelve people with liver disease.
Rudolph 2002[11]	8 people with blocked bile ducts from pancreatic cancer, with drains	Crossover	UDCA at an equal molar dose	Yes (order)	Not stated	1,000 mg (vs 750 mg UDCA)	Short study periods	Absorption	64.6% of TUDCA vs 55.1% of UDCA absorbed; not a significant difference.	Eight people; an unusual group.
Simoni 2013[39]	24 healthy volunteers	Test of gut transit time	Before and after loperamide	No	Not stated	Single dose (amount not stated)	Single dose	When TUDCA appears in saliva	Used as a marker because TUDCA is absorbed in the last part of the small intestine (the ileum).	Not a treatment study.
Hemingway 2020[12]	12 healthy young adults	Single dose vs placebo	Placebo	Not stated	Not stated	1,500 mg once	Single dose	Blood levels (and blood-vessel function)	Blood TUDCA rose by 145 ng/mL and UDCA by 560 ng/mL; blood-vessel function unchanged.	A blood-vessel study; included only for its blood levels.

Download the table (CSV)

Taken from each study's published summary, or the full text where available. Searched October 17, 2026.

How we did this review

Search. On October 17, 2026 we searched PubMed (65 searches) and Europe PMC (36 searches) for every spelling of the ingredient (tauroursodeoxycholic acid, tauroursodeoxycholate, TUDCA, taurursodiol, ursodoxicoltaurine), alone and combined with gallbladder, bile, liver and gut conditions. We screened the titles of more than 1,400 PubMed records and searched ClinicalTrials.gov for registered trials.^[16] We also read the official medicine labels in Italy and Turkey.

What we included. Published studies in people that gave TUDCA by mouth for a gallbladder, bile, liver, gut or metabolic-liver outcome, or that measured how it is absorbed. We excluded studies in animals and cells, reviews, studies of UDCA alone, and the combination drug sodium phenylbutyrate–taurursodiol.

How we appraised them. For every study we recorded the same fields: who took part, the design, the comparison, whether it was randomized and blinded, the dose and length, what was measured, the result, and the main limits. We took them from the study itself, not from secondary sources, and wrote “not stated” where the study does not say.

How we graded the evidence. Each use gets two things: what the studies found, and a grade for how much research stands behind that finding. The grade describes the research, not the ingredient. A low grade means a finding has not yet been confirmed, not that it has been disproved.

• Strong: consistent results from several well-sized randomized, blinded trials measuring outcomes that matter to patients. No use of TUDCA has reached this level yet.
• Moderate: at least one well-sized randomized trial, with laboratory outcomes or short follow-up.
• Early: one placebo-controlled trial, or several small controlled trials, or a licensed medical use resting on small trials.
• Preliminary: one or two studies that were small, uncontrolled or unblinded.
• Not yet studied: no published study in people.

Limits of this review. For most of the older studies we could read only the English summary; several full texts are in Italian. We could not search Chinese-language databases (CNKI, Wanfang), Embase, or the WHO and Chinese trial registries, so studies indexed only there may be missing. Several older records have no published summary at all, and we could not appraise them.

About this review

Who wrote it. The Dr.Primal editorial team. Our editorial standards explain how we work.

Conflict of interest. Dr.Primal sells a TUDCA supplement. That is why we have kept this page free of product links and offers, reported results that do not favor TUDCA alongside those that do, and appraised every study in the same way.

Medical review. This review has not been checked by a physician. The Dr.Primal editorial team wrote it and fact-checked every figure against its primary source. If a credentialed reviewer checks it later, we will name them here and record it in the version history.

Versions. Version 1.0, October 17, 2026: first publication. We will update this page when new studies are published, and record every change here.

Corrections. If you find an error or a study we missed, please tell us.

This review describes published research. It is not medical advice and does not replace advice from your doctor. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease.