Hva er ingredeance i Viagra?

Sildenafil citrate .... den kjemiske sminke is
1-[4-ethoxy-3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H
-pyrazolo[4,3-d
]pyrimidin-5-yl)phenylsulfonyl]-4-methylpiperazine