WAY-357919 is primarily used in scientific research to investigate pain modulation pathways. It acts as a potent and selective antagonist for the NK3 receptor (neurokinin 3 receptor), making it a valuable tool in studying the role of tachykinin signaling in central nervous system disorders. Researchers utilize this compound to explore potential therapeutic targets in conditions such as chronic pain, depression, and schizophrenia. Due to its high selectivity, it helps isolate NK3 receptor activity in neuropharmacological studies, contributing to the development of novel CNS-acting drugs. It is not used in clinical medicine and remains restricted to preclinical research settings.