Legal status · United States
Is TUDCA legal in the United States?
Written by Aaron CuhaReviewed Sep 2026
Direct answer
TUDCA can be sold in the United States as a supplement or cosmetic ingredient. Its legal category is "Sold as a supplement". That is not approval as a drug. FDA has not checked any health claim made for it. Versions you inject, and "research use only" versions, fall outside supplement rules, so that label does not make them legal to use in people. On the evidence, 3 completed human trials are cited on its profile.
- People given it
- 54
- Found nothing
- 2
Legal category
Sold as a supplement
Sold as a dietary supplement. The combination product containing it was approved for ALS. Its maker then pulled it from sale after a failed final-stage study. Its parent compound, ursodeoxycholic acid, is a prescription medicine with its own page on this site.
Reviewed Sep 2026. This is a legal category, not legal advice.
A "research use only" label on a vial does not make it legal to use on people.
TUDCA in the United States at a glance
| Legal category | Sold as a supplement |
|---|---|
| Note | Sold as a dietary supplement. The combination product containing it was approved for ALS. Its maker then pulled it from sale after a failed final-stage study. Its parent compound, ursodeoxycholic acid, is a prescription medicine with its own page on this site. |
| FDA approval status | Not approved on its own. A fixed mix of sodium phenylbutyrate and taurursodiol was FDA-approved for ALS. Its maker then chose to pull it from sale, after the final-stage PHOENIX study found no change in its main measure of how well patients could function. TUDCA on its own is sold as a dietary supplement. |
| Studies in people | 5 of 6 sources on the profile |
| Reviewed | Sep 2026 |
The legal category and note come from the TUDCA profile. We checked them against U.S. Food and Drug Administration (FDA) listings on the reviewed date.
What this means
- 01
TUDCA can be sold in the United States as a supplement, food or cosmetic ingredient, under the legal category above. It has no approval as a drug.
- 02
Being sold as a supplement means FDA has not checked any health claim. The makers are responsible for safety and labels, and quality varies from product to product.
- 03
Versions you inject, and "research use only" versions, are not supplements. That label does not make them legal to use in people, and anything you inject falls under the rules for medicines.
What TUDCA is
In twenty obese adults over four weeks, insulin sensitivity in the liver and muscle rose about 30 percent on a detailed lab test. Fat tissue did not respond. The cell stress markers the drug was meant to fix did not change either. In ALS, a large final-stage study of TUDCA combined with sodium phenylbutyrate missed its goal, and the maker pulled the approved product from the market.
TUDCA is a bile acid. It is UDCA with the amino acid taurine attached.
How it works: TUDCA is a water-loving bile acid that acts as a chemical helper for proteins. It helps them fold properly, and it eases a kind of stress in the part of the cell that makes proteins.
Approval history: Not approved on its own. A fixed mix of sodium phenylbutyrate and taurursodiol was FDA-approved for ALS. Its maker then chose to pull it from sale, after the final-stage PHOENIX study found no change in its main measure of how well patients could function. TUDCA on its own is sold as a dietary supplement.
How FDA treats this kind of product
Approves prescription drugs, each for a named use. It also acts against unapproved products, including peptides sold online. Compounding pharmacies, which mix drugs to order, may make some compounds with a prescription. That only applies when the FDA puts the compound in a category of bulk ingredients it allows.
The legal category above is how The Longevity Archive reads U.S. Food and Drug Administration listings for TUDCA on the reviewed date. It is not a legal opinion. Rules change. Bringing a compound into the country, prescribing it and owning it can each be treated differently. Check with the agency before you act on anything here.
TUDCA in sport and the military
Whether TUDCA is banned in sport is set by the World Anti-Doping Code and by military rules, not by its legal status in the United States. Before you compete or get tested, look up TUDCA by name on the Prohibited List, or look up a named product in Global DRO. Under the World Anti-Doping Code, category S0 bans, at all times, any drug-like substance that meets two tests. No other section of the List covers it. And no government health regulator anywhere has a current approval for it as a treatment in people. Many substances that are approved somewhere are banned by name in another section. So approval does not mean a substance is allowed in sport.
- WADA Prohibited List
- Global DRO (check a named product)
- USADA (US athletes)
- Operation Supplement Safety (US service members)
The rules you compete or serve under decide this, not this page.
TUDCA in other countries
Frequently asked questions
Is TUDCA legal in the United States?
TUDCA can be sold in the United States as a supplement or cosmetic ingredient. Its legal category is "Sold as a supplement". That is not approval as a drug. FDA has not checked any health claim made for it. Versions you inject, and "research use only" versions, fall outside supplement rules, so that label does not make them legal to use in people. On the evidence, 3 completed human trials are cited on its profile. Note: Sold as a dietary supplement. The combination product containing it was approved for ALS. Its maker then pulled it from sale after a failed final-stage study. Its parent compound, ursodeoxycholic acid, is a prescription medicine with its own page on this site.
Can I buy TUDCA in the United States?
Yes, as a supplement or cosmetic. In the United States, TUDCA has the legal category "Sold as a supplement". So products you swallow, put on your skin or use as a cosmetic can be sold under supplement rules. Versions you inject, and products labeled "research use only", are not supplements. They are not approved for use in people. Note: Sold as a dietary supplement. The combination product containing it was approved for ALS. Its maker then pulled it from sale after a failed final-stage study. Its parent compound, ursodeoxycholic acid, is a prescription medicine with its own page on this site.
Is TUDCA FDA approved?
No. FDA status: Not approved on its own. A fixed mix of sodium phenylbutyrate and taurursodiol was FDA-approved for ALS. Its maker then chose to pull it from sale, after the final-stage PHOENIX study found no change in its main measure of how well patients could function. TUDCA on its own is sold as a dietary supplement.. Current US legal category: "Sold as a supplement". On the evidence, 3 completed human trials are cited on its profile.
Related compounds in the United States
Full research profile
How TUDCA works, the studies we cite, FDA status and the full legal summary are all on its compound profile.
TUDCA profileThis page is general information about the legal status of TUDCA in the United States, current as of Sep 2026. It is not legal advice. Legal status changes. For your own situation, check with U.S. Food and Drug Administration or ask a lawyer. Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use. Sellers named on the price pages are ranked by certificate tier, then price, and any affiliate income is disclosed there. Naming a seller is not a recommendation to buy or use anything.