(±)-DOI hydrochloride is primarily used in scientific research to study the serotonin receptor system, particularly the 5-HT2A and 5-HT2C receptors. It is a potent agonist for these receptors and is often employed in behavioral and neuropharmacological studies to investigate the role of serotonin in various physiological and psychological processes. Researchers use it to explore its effects on perception, mood, and cognition, as well as its potential involvement in conditions such as schizophrenia, depression, and anxiety. Additionally, it is utilized in animal models to study hallucinogenic effects and their underlying mechanisms. Its application is strictly limited to laboratory settings and is not used in clinical or therapeutic contexts.