Viagra impotence pills. Hand holds 50 milligram Viagra pills (sildenafil citrate) to treat male impotence. Viagra is the first oral pill for impo- tence. Unlike other treatments that directly cause penile erections,Viagra affects the response to sexual stimulation. Viagra enhances the smooth muscle relaxant effects of nitric oxide,a substance normally released in response to sexual stimulation. Smooth muscle relaxation allows blood to enter the penis leading to an erection. The recommended dose is 50mg taken one hour before sexual activity; 25mg and 100mg pills are also available. Viagra,made by Pfizer Pharmaceuticals,was approved for use in the U.S.A. in 1998 | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Meadows, Matt |
Taille de l’image : | 3543 px × 2912 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : |
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