TUDCA has been investigated as a potential treatment for amyotrophic lateral sclerosis (ALS, also known as motor neuron disease or Lou Gehrig's disease). While TUDCA appears safe and showed potential in earlier studies, robust evidence from large randomized controlled trials does not support its efficacy in treating ALS. Further research is needed to clarify its role, if any, in managing the disease. An overview of the current evidence is provided below.
A preliminary study in 2015 suggested that TUDCA might slow disease progression, as measured by improvements in the ALS Functional Rating Scale-Revised (ALSFRS-R).[1] These findings led to the off-label prescription of TUDCA in Italy's Emilia Romagna Region for ALS patients,[2] and a retrospective analysis of the ALS registry in that region of Italy suggested that TUDCA, at dosages up to 1,000 mg/day, might improve survival in patients with ALS compared to patients receiving standard care.[3] However, despite these promising early results, the large-scale Phase 3 randomized controlled trial TUDCA-ALS found no significant benefit of TUDCA in reducing ALS progression.[4][5][6][7]
Similarly, early preliminary studies of a combination therapy for ALS showed promise.[8][9][10] The drug used in these studies was called Relyvrio, or AMX0035, and contains sodium phenylbutyrate and taurursodiol (taurursodiol is another name for TUDCA). However, the PHOENIX study, a large-scale Phase 3 trial, found no significant benefit of Relyvrio in reducing ALS progression.[11][12] Subsequently, Relyvrio was withdrawn from the US and Canadian markets in 2024.[13]