WAY-299819 is a selective agonist for the GPR139 receptor, a G-protein-coupled receptor expressed primarily in the brain, particularly in regions associated with motor control and reward processing. Its main application lies in neuroscience research, where it is used to probe the functional role of GPR139 in behavioral and neurochemical pathways. Studies have utilized WAY-299819 to investigate its potential involvement in conditions such as Parkinson’s disease, schizophrenia, and addiction, due to the receptor’s modulation of dopamine and glutamate signaling. It has also been employed to assess the effects of GPR139 activation on locomotor activity and cognitive performance in animal models. Due to its selectivity and blood-brain barrier permeability, it serves as a valuable pharmacological tool for validating GPR139 as a therapeutic target in central nervous system disorders.