(S)-3-Amino-4-(4-fluorophenyl)butanoic acid hydrochloride is primarily used in pharmaceutical research and development, particularly in the synthesis of active pharmaceutical ingredients (APIs). It serves as a key intermediate in the production of drugs targeting neurological and psychiatric disorders, such as epilepsy, anxiety, and depression. Its structure, featuring a fluorophenyl group and an amino acid moiety, makes it valuable for designing compounds that interact with specific receptors or enzymes in the central nervous system. Additionally, it is utilized in the study of enzyme inhibition and receptor modulation, aiding in the discovery of novel therapeutic agents. Its hydrochloride form ensures stability and solubility, making it suitable for various experimental and formulation applications.