N-Desmethyl sildenafil is a major metabolite of sildenafil . N-Desmethyl sildenafil is formed via oxidative metabolism of sildenafil by the cytochrome (CYP) P450 isoforms CYP3A4, CYP3A5, and CYP3A7.

N-Desmethyl Sildenafil (citrate)

DMF:14 mg/mL
DMSO:10 mg/mL
Powder: -20°C for 3 years
In solvent: -80°C for 2 years