L-taurine is an amino sulfonic acid found abundantly in the brain, heart, and other tissues, and it has been investigated for its potential role in stress modulation. Preclinical studies, primarily in animal models, suggest that taurine may exert anxiolytic (anxiety-reducing) and stress-attenuating effects. These effects are believed to arise through taurine's modulation of the GABAergic system, its antioxidant properties, and its ability to regulate neurotransmitter systems involved in the stress response, such as glutamate and cortisol pathways.

In terms of human research, the evidence is limited but growing. Some small-scale clinical studies and pilot trials have suggested that taurine supplementation might help reduce markers of psychological stress and anxiety, often in combination with other nutrients or as part of energy drinks. However, these studies are generally of low quality, with small sample sizes and methodological limitations, making it difficult to draw firm conclusions.

Overall, while there is a plausible biological rationale and some animal and preliminary human data suggesting that L-taurine may help modulate the stress response, robust scientific validation from large, well-controlled human trials is lacking. Thus, the evidence rating for taurine's use in stress support is moderate to low (2/5), reflecting suggestive but not definitive scientific support.