Man taking a viagra tablet. Viagra is made by Pfizer Pharmaceuticals and is the trade name for the drug sildenafil citrate. It is used to treat erecti

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Man taking a viagra tablet. Viagra is made by Pfizer Pharmaceuticals and is the trade name for the drug sildenafil citrate. It is used to treat erectile dysfunction by enhancing the smooth muscle relaxant effects of nitric oxide, a chemical that is released in response to sexual stimulation. Relaxation of the smooth muscle allows blood to enter the penis, resulting in an erection.

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Size: 3543px × 5315px
Photo credit: © MARK THOMAS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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