Is TUDCA From Bear Bile? How TUDCA Is Made Today

TUDCA is found in unusually large amounts in bear bile, which has been used in Chinese medicine since at least 659 AD, but TUDCA doesn't have to come from bears. It can be made in a lab by joining UDCA to the amino acid taurine, or from chicken bile using enzymes, and Dr.Primal's TUDCA is made synthetically, with no bears involved.

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Search for TUDCA and you will soon find bear bile: photographs of bear farms, claims of thousands of years of use, and supplement pages promising their TUDCA is "cruelty-free". Many people now want to know whether the supplement in their cupboard has anything to do with bears.

This guide answers that question plainly. It explains why bears have so much TUDCA, how bear bile has been used, what bear bile farming involves and what the law says, and how TUDCA is made today.

Is TUDCA From Bear Bile?

TUDCA occurs naturally in bear bile, but it doesn't have to come from bears. It can be made by chemically joining UDCA to taurine, or by converting bile acids from chicken bile with enzymes [1]. Dr.Primal's TUDCA is made synthetically, and no bears or bear bile are involved in making it.

TUDCA isn't unique to bears either. Your body makes small amounts: gut bacteria make UDCA, and the liver joins it to taurine [2]. Together with UDCA, it makes up about 2% of the bile acids in human bile [2]. Our guide to what TUDCA is explains each step.

Why Is Bear Bile So Rich in TUDCA?

Bears make far more UDCA than the other animals studied alongside them, and almost all of it is joined to taurine, which makes it TUDCA. In a study of bile from bears, pandas and related carnivores, UDCA averaged about a third of the bile acids in American black bears and under 20% in the other bears studied, while in the giant panda and related carnivores it was absent or found only in traces [3].

That makes bear bile far richer in TUDCA than other animals' bile [1]. In a 2025 analysis of bile powders sold in China, TUDCA was detected in bear bile and bear bile substitute products, but not in ox bile powder [4].

What Is Bear Bile Used For?

Bear bile has a long history in traditional Chinese medicine. It was first recorded in an official Chinese materia medica in 659 AD, and its traditional uses were for complaints such as fever, inflammation, convulsions, eye problems, sores and hemorrhoids [5]. Its use for the liver is more recent [5].

Claims that bear bile has been used "for thousands of years" go further than the records: the first official entry dates to 659 AD, more than 1,300 years ago [5]. A long history of use also isn't evidence that a remedy works.

Where Did the Name UDCA Come From?

UDCA, the bile acid that TUDCA is built from, takes its name from bears. Ursodeoxycholic acid was described in 1927 by a Japanese researcher working with bear bile [6], and "urso" comes from Ursus, the Latin word for bear. Chemists learned to make it in the lab in the 1950s [5].

Today UDCA is also a long-established prescription medicine in the US, called ursodiol, which doctors prescribe for some gallstones and liver conditions [7]. Commercial bile acids, including the starting materials for making UDCA, are often made from cattle bile [8].

What Is Bear Bile Farming?

Bear bile farming is the practice of keeping bears in captivity to collect bile from them, and it has drawn sustained criticism on animal welfare grounds [5, 9]. Rules have changed over time: in China, current regulations ban small cages and external catheters, according to a 2022 study [9], and according to a 2009 review, the health ministry stopped approving new bear bile health products in 2001 [5].

Demand hasn't disappeared. In a 2022 survey of 1,421 traditional medicine consumers in China, about half fell into groups that preferred all-natural products and disliked synthetic ones; in a choice exercise, many said they would switch between wild, farmed and synthetic products as an illness got worse [9]. Researchers have worked on substitutes for animal welfare reasons, including TUDCA made from chicken bile [1].

Is Bear Bile Legal in the US?

Bringing bear bile into the US requires wildlife permits. The Asiatic black bear, the species farmed for bile [1, 9], is listed in Appendix I of CITES, the international treaty on trade in endangered species, which generally bars commercial trade [10], and US import permits for Appendix I species aren't issued for primarily commercial purposes [11, 12]. The American black bear is listed in Appendix II, which allows controlled trade with permits [13].

Selling bear parts within the US is decided state by state, and federal law makes it an offense to trade wildlife across state lines in violation of state law [14]. In 2000, a Senate report found that most states prohibited the sale of bear parts [15]; the rules may have changed since.

How Is TUDCA Made Today?

TUDCA is made commercially in two main ways [1]:

• Chemical synthesis: UDCA is joined to taurine. UDCA itself is usually made from other bile acids, and commercial bile acids are often made from cattle bile [8].
• Enzyme conversion: bile acids from chicken bile are converted into TUDCA using enzymes, a route that a 2024 review, one of whose authors works for a producer, describes as already used at industrial scale.

We found no source on which route supplement makers use. If it matters to you, ask the maker directly.

Does "Synthetic TUDCA" Mean No Animals Are Involved?

Not necessarily. "Synthetic" means the TUDCA was made by a chemical process rather than collected from an animal, but the starting materials for that process can be bile acids from cattle or chicken bile [8, 1]. A synthetic TUDCA can be bear-free without being animal-free.

That is why we describe Dr.Primal's TUDCA as made synthetically and not from bears, and don't call it vegan. If you follow a vegan diet or have alpha-gal syndrome, an allergy to a molecule found in most mammals [16], ask any maker about its starting materials and check the capsule material. Our guide to vegan and alpha-gal alternatives to ox bile covers those situations.

Where Does TUDCA Fit After Gallbladder Removal?

After gallbladder removal, bile flows directly from the liver into the small intestine instead of being stored for meals [17]. Dr.Primal's TUDCA is made for life after gallbladder removal and taken with meals, to support healthy bile flow and fat digestion. Our guide to TUDCA benefits sets out what the research in people shows.

In Summary: TUDCA and Bear Bile

Bear bile is unusually rich in TUDCA and has been part of Chinese medicine since at least 659 AD, and UDCA was named after bears. TUDCA today can be made without bears, by joining UDCA to taurine or converting chicken bile acids, though "synthetic" doesn't automatically mean animal-free.

If you are working out whether bile is behind your symptoms after meals, our digestion quiz is a quick way to put your symptoms and habits in order.

This article is for general education and is not a substitute for advice from your doctor. TUDCA is sold as a dietary supplement. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.