Sildenafil N-Oxide is a key metabolite of sildenafil, primarily used in pharmacological research to understand the mechanism of action and metabolic pathways of sildenafil, the active ingredient in medications for treating erectile dysfunction and pulmonary arterial hypertension. It specifically helps investigate the role of cytochrome P450 enzymes in the biotransformation of sildenafil to its N-oxide form. Additionally, it is employed in the development of chemical and biological analytical methods to quantify sildenafil and its metabolites in biological samples, supporting evaluations of drug efficacy, pharmacokinetics, and safety.