Used as a stable isotope-labeled internal standard in mass spectrometry and chromatography for accurate quantification of GABA (gamma-aminobutyric acid) in biological samples such as brain tissue, cerebrospinal fluid, and plasma. Its primary application lies in neuroscience research, where it helps study neurotransmitter metabolism, GABAergic system function, and neurological disorders like epilepsy, anxiety, and insomnia. The ¹⁵N label allows differentiation from endogenous GABA, improving measurement precision and reliability in metabolic tracing and pharmacokinetic studies.