TUDCA: ALS Trials, Ursodiol Difference and Safety
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TUDCA (Tauroursodeoxycholic Acid): half-life, strengths and approval status

Amounts studied · Approval status · Half-life notes

What is TUDCA?

TUDCA (tauroursodeoxycholic acid) is a bile acid made in the liver; it is ursodeoxycholic acid (ursodiol) bound to the amino acid taurine. It has been used for chronic liver diseases that slow bile flow, and in research it has been studied mainly for ALS (amyotrophic lateral sclerosis).

Also known as: tauroursodeoxycholic acid, tauroursodiol.

Amounts studied

A placebo-controlled ALS pilot trial used 1 g twice a day for 54 weeks (Elia 2016). These are study protocols, not a recommendation.

Approval status and how it is used

It is sold in the US as a dietary supplement. Under the 1994 dietary supplement law (DSHEA), FDA does not approve dietary supplements before they are marketed, and the maker, not FDA, is responsible for safety and labeling.

How it differs from ursodiol: ursodiol (ursodeoxycholic acid) is an FDA-approved prescription drug for dissolving certain gallbladder stones and for preventing gallstones during rapid weight loss in people with obesity. The ursodiol label says the liver binds absorbed ursodiol to glycine or taurine; TUDCA is the taurine-bound form. TUDCA itself is not an FDA-approved drug.

What studies show: in a pilot trial of 34 people with ALS already taking riluzole, TUDCA (1 g twice a day for 54 weeks) was well tolerated, and more people improved on TUDCA (87%) than on placebo (43%); the authors call these preliminary data (Elia 2016). A larger phase 3 trial (TUDCA-ALS, planned for 320 people) was set up to test this; its protocol was published in 2022, and the company supplying the TUDCA is an industrial partner (Albanese 2022). A different product combining TUDCA with sodium phenylbutyrate was FDA-approved for ALS, but its phase 3 trial (PHOENIX) found no benefit at 48 weeks and the maker moved to withdraw it from the US and Canadian markets (Ketabforoush 2024).

Safety: side effects were no more common than with placebo in the pilot trial (Elia 2016). The sources here do not describe drug interactions.

TUDCA half-life and time to peak

  • Half-lifeNot listed
  • Time to peak (Tmax)Not listed

We could not find a single published half-life or time to peak for TUDCA that applies to a supplement dose, so we do not list one.

How to track TUDCA in Dose Track

  1. Add TUDCA as a custom compound. Start typing its name and Dose Track fills in the details from its research library for you to check, and it sits next to everything else you take.
  2. Log each dose when you take it so your history shows exactly what you took and when.
  3. Set reminders on your own schedule, whether that is daily, weekly or every few days.
  4. Your log is stored on your phone and no account is needed. Data only leaves it for features you choose, like AI answers and lab reading.

How Dose Track handles peptides · Reconstitution calculator · Half-life calculator

Milk Thistle (Silymarin)silymarin, Silybum marianum NAC (N-Acetylcysteine)N-acetylcysteine, N-acetyl-L-cysteine Taurine

Frequently asked questions

What is the half-life of TUDCA?+
We could not find a single published half-life or time to peak for TUDCA that applies to a supplement dose, so we do not list one.
Is TUDCA the same as ursodiol?+
No, but they are related. Ursodiol is an FDA-approved prescription drug for certain gallstones. TUDCA is ursodiol bound to taurine, a form the liver also makes from ursodiol, and it is sold as a supplement, not as an approved drug.
Does TUDCA help ALS?+
It is not proven. A 34-person pilot trial found slower decline, which the authors called preliminary, and a larger trial was set up to test it. A related combination drug was withdrawn after its phase 3 trial found no benefit.
Can I track TUDCA in Dose Track?+
Yes. TUDCA is in Dose Track's research library, so when you add it as a custom compound its details are filled in for you to check. You can then log each dose next to your other compounds, set reminders on your own schedule, and see your history next to your lab results. Your log is stored on your phone and no account is needed. Data only leaves it for features you choose, like AI answers and lab reading.

Sources

  1. Elia AE, et al. Tauroursodeoxycholic acid in the treatment of patients with amyotrophic lateral sclerosis. Eur J Neurol. 2016;23(1):45-52.
  2. Albanese A, et al. Tauroursodeoxycholic acid in patients with amyotrophic lateral sclerosis: the TUDCA-ALS trial protocol. Front Neurol. 2022;13:1009113.
  3. Ketabforoush A, et al. Sodium phenylbutyrate and tauroursodeoxycholic acid: a story of hope turned to disappointment in amyotrophic lateral sclerosis treatment. Clin Drug Investig. 2024;44(7):495-512.
  4. DailyMed. Ursodiol capsule (Actavis Pharma), prescribing information.
  5. FDA. Questions and answers on dietary supplements.

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