What it's actually good for
Taurine is a sulfur-containing amino acid (technically an amino sulfonic acid) that the body can synthesize but may not produce in sufficient quantities under stress, illness, or aging. The strongest human evidence is cardiovascular: a meta-analysis of controlled trials shows that taurine supplementation at 1-6 g/day modestly but significantly lowers blood pressure, and individual RCTs suggest improvements in endothelial function and lipid profiles. Taurine also acts as an antioxidant and osmolyte in the heart, brain, and retina. The compound gained significant public attention after a 2023 Science paper demonstrated that taurine deficiency drives aging hallmarks in mice and that supplementation extended mouse lifespan by 10-12%. However, it is critical to note that no human longevity trials exist, and the leap from mouse lifespan extension to human benefit is large and uncertain. Taurine earns a B for cardiovascular endpoints based on consistent RCT data, but the longevity claims remain speculative in humans. The energy-related benefits often attributed to taurine via energy drinks are likely more attributable to caffeine and sugar than to taurine itself, though taurine may play a supporting role in exercise performance at higher doses.