R-(−)-Fluoxetine hydrochloride is the specific R-enantiomer of fluoxetine hydrochloride, a selective serotonin reuptake inhibitor (SSRI) class compound. It is primarily utilized in pharmaceutical research, drug development, and stereochemistry studies to investigate the differential pharmacological activities of fluoxetine enantiomers. While the racemic (R/S) form of fluoxetine hydrochloride is clinically approved for treating major depressive disorder, obsessive-compulsive disorder (OCD), bulimia nervosa, panic disorder, premenstrual dysphoric disorder (PMDD), and certain anxiety disorders by restoring serotonin balance in the brain to improve mood, sleep, appetite, and energy, the R-enantiomer exhibits reduced SSRI potency compared to the more active S-enantiomer and may contribute to other effects such as norepinephrine reuptake inhibition. This high-purity reagent is intended for laboratory and analytical applications, not direct clinical use, and is typically administered orally in therapeutic formulations of the racemate.