TUDCA and Athletic Performance: Is There Any Effect?

Tauroursodeoxycholic acid, better known as TUDCA, has moved from hepatology journals into the supplement cabinets of bodybuilders and endurance athletes. It is mostly marketed as liver support, but newer claims suggest benefits for insulin sensitivity, muscle and even performance. Our editorial team examined what the evidence actually shows and where the gaps are.

What TUDCA is

TUDCA is a bile acid formed when ursodeoxycholic acid (UDCA) is conjugated with taurine. Small amounts occur naturally in human bile. Larger amounts are found in bear bile, which has been used in traditional Chinese medicine for centuries; modern supplements use synthetic or semi-synthetic sources.

Its close relative UDCA, known in the US by the generic name ursodiol, is an FDA-approved prescription drug for dissolving certain gallstones and treating primary biliary cholangitis. TUDCA itself is not approved as a drug in the US and is sold as a dietary supplement.

Bile acids are more than digestive detergents. They act as signaling molecules that influence metabolism through receptors such as FXR and TGR5. TUDCA, in particular, has drawn research attention as a "chemical chaperone" that may help cells cope with endoplasmic reticulum (ER) stress.

ER stress occurs when cells cannot fold proteins properly, a state linked to insulin resistance, fatty liver and neurodegenerative diseases. Ozcan and colleagues (2006) showed that TUDCA and a related compound reduced ER stress and restored glucose control in obese, diabetic mice.

Why athletes became interested

The first reason is liver protection. Oral anabolic steroids, especially 17-alpha-alkylated compounds, can cause cholestasis, liver enzyme elevations and, in rare cases, tumors. Reviews such as that by Solimini and colleagues (2017) document hepatotoxicity associated with illicit steroid use. Some users take TUDCA hoping to offset this damage.

The second reason is metabolic. Because of the insulin sensitivity findings in research, TUDCA has been promoted as a way to improve nutrient partitioning, meaning more glucose directed to muscle rather than fat.

The third reason is muscle and recovery. Laboratory studies have suggested that reducing ER stress might protect muscle cells. This has fueled speculation about faster recovery or better adaptation to training.

It is important to state clearly: TUDCA does not make steroid use safe. No supplement can neutralize the liver, heart and hormonal risks of anabolic steroids. Using TUDCA as a justification for continued use of hepatotoxic drugs is a dangerous misconception.

Evidence for metabolic and muscle effects

The most cited human study is by Kars and colleagues (2010). Obese, insulin-resistant men and women received 1,750 mg of TUDCA per day or placebo for four weeks. TUDCA improved insulin sensitivity in the liver and muscle by about 30 percent, measured with the gold-standard clamp technique, but had no effect on fat tissue insulin sensitivity.

That is a meaningful finding, but it applies to a small group of sedentary, obese people over a short period. Whether a similar effect occurs in lean, trained athletes, who already have high insulin sensitivity, is unknown.

Muscle data come mostly from cell and animal research. Some rodent studies suggest TUDCA reduces muscle damage or atrophy in disease models, but these findings have not been replicated in human athletes.

In neurology, TUDCA attracted attention as part of a combination with sodium phenylbutyrate for amyotrophic lateral sclerosis. The CENTAUR trial (Paganoni et al., 2020) reported a slower functional decline, leading to conditional US approval in 2022. However, the larger confirmatory trial did not show a benefit, and the product was withdrawn from the US market in 2024. This history illustrates how promising early results do not always hold up.

Does TUDCA improve performance?

To our knowledge, there are no published randomized controlled trials examining whether TUDCA improves strength, power, endurance or body composition in healthy athletes. Claims of performance benefits are extrapolations from animal research and from studies in metabolic disease.

Vang and colleagues (2014) reviewed the expanding non-liver uses of UDCA and TUDCA and noted promising mechanistic work alongside the need for well-designed clinical trials. That conclusion still holds for sport.

• No controlled data show improved athletic performance with TUDCA.
• Metabolic benefits have been observed only in insulin-resistant people.
• Liver-protection claims are extrapolated from different clinical conditions.

For an athlete looking for a performance edge, TUDCA is therefore not a rational choice. Training, nutrition, sleep and well-researched supplements offer far more predictable returns.

Safety, quality and limitations

In clinical studies, TUDCA has generally been well tolerated. The most common side effects are gastrointestinal, such as diarrhea or abdominal discomfort. Data on long-term use in healthy people are limited.

Bile acids can interact with medications, particularly those affecting cholesterol absorption, such as bile acid sequestrants, and possibly with drugs that rely on bile for absorption. People with gallbladder disease, bile duct obstruction or liver disease should only use bile acid products under medical supervision.

Because TUDCA is sold as a supplement, product quality varies. Herbal and dietary supplements are a recognized cause of liver injury in the US, as described by Navarro and colleagues (2017), and contamination or mislabeling cannot be excluded. Independent third-party testing reduces, but does not eliminate, this risk.

If someone is concerned about liver health, the answer is laboratory monitoring and a physician's assessment, not self-treatment. Rising liver enzymes, jaundice, dark urine, itching or pale stools require urgent medical attention.

The Editorial Team's Conclusions

TUDCA is a biologically interesting bile acid with promising research in metabolic and liver disease, but there is no evidence that it improves athletic performance.

Its insulin-sensitizing effect has been shown only in insulin-resistant, obese adults in a short study. Liver-protection claims in sport are not supported by controlled data.

Most importantly, TUDCA should never be viewed as a safety net for hepatotoxic drug use. Proper medical monitoring and avoiding the cause are the only effective strategies.

We also recommend our articles on liver enzymes in strength athletes, on milk thistle for liver support, and on how oral anabolic steroids affect the liver.

References

1. Kars M, Yang L, Gregor MF, et al. Tauroursodeoxycholic acid may improve liver and muscle but not adipose tissue insulin sensitivity in obese men and women. Diabetes. 2010;59(8):1899–1905.
2. Ozcan U, Yilmaz E, Ozcan L, et al. Chemical chaperones reduce ER stress and restore glucose homeostasis in a mouse model of type 2 diabetes. Science. 2006;313(5790):1137–1140.
3. Paganoni S, Macklin EA, Hendrix S, et al. Trial of sodium phenylbutyrate-taurursodiol for amyotrophic lateral sclerosis. N Engl J Med. 2020;383(10):919–930.
4. Vang S, Longley K, Steer CJ, Low WC. The unexpected uses of urso- and tauroursodeoxycholic acid in the treatment of non-liver diseases. Glob Adv Health Med. 2014;3(3):58–69.
5. Solimini R, Rotolo MC, Mastrobattista L, et al. Hepatotoxicity associated with illicit use of anabolic androgenic steroids in doping. Eur Rev Med Pharmacol Sci. 2017;21(1 Suppl):7–16.
6. Navarro VJ, Khan I, Björnsson E, et al. Liver injury from herbal and dietary supplements. Hepatology. 2017;65(1):363–373.