Viagra, a blue colored diamond shaped pill, contains Sildenafil as the active ingredient. It is prescribed for men suffering from Erectile Dysfunction. Viagra is a phosphodiesterase inhibitor which is used to treat impotence or erectile dysfunction. Viagra, along with sexual stimulation, increases the blood flow into the penis to achieve and maintain an erection.

The Sildenafil in Viagra increases the blood flow to penis in response to sexual stimulation. Viagra relaxes the blood vessels in the penile region thus allowing blood to flow into the penis causing an erection.
Viagra helps in achieving erection only when a man is sexually stimulated.
Viagra is not an aphrodisiac. It doesn’t help in increasing sexual stimulation. It helps in curing erectile dysfunction.
Viagra takes about an hour for onset. You should avoid heavy meals before taking Viagra. It is always good to take Viagra empty stomach.
Alcohol consumption should either be avoided or kept moderate as excessive alcohol consumption lowers the effect of Viagra and impairs sexual performance.