A pilot study has provided evidence that the hydrophilic bile acid TUDCA is safe and possibly effective for the treatment of amyotrophic lateral sclerosis (ALS). 34 patients with ALS were randomly assigned to TUDCA or placebo as add-on therapy to riluzole. TUDCA was well tolerated, and the patients who received the drug showed significantly reduced disease progression over the 54-week treatment period compared with the placebo group.