Homotaurine, also known as tramiprosate, is a synthetic amino sulfonate compound originally investigated for its neuroprotective properties, particularly in the context of Alzheimer's disease and related cognitive decline. Its mechanism of action is primarily based on its ability to bind to soluble amyloid-beta (Aβ) peptide, thereby inhibiting its aggregation into neurotoxic fibrils and plaques—a hallmark of Alzheimer's pathology. Several clinical trials, most notably the Alphase study (2009), have explored the effect of homotaurine on cognitive decline in patients with mild to moderate Alzheimer's disease. While preclinical and early-phase clinical trials showed some promise in reducing Aβ aggregation and modest cognitive benefits, the large phase III trials failed to demonstrate statistically significant efficacy on primary cognitive endpoints compared to placebo.

Nevertheless, some subgroup analyses suggested possible benefits in patients without the APOE4 genetic risk factor. Homotaurine is not approved as a pharmaceutical treatment for Alzheimer's disease or senility but is marketed as a dietary supplement in some regions for cognitive support. The scientific evidence supporting its use for senility, defined broadly as age-related cognitive decline, is limited and mixed, leading to a modest rating for evidence. Its use is based on plausible mechanisms and some clinical data, but robust validation is lacking.