Viagra 50 mg tablet is a prescription medicine used to treat erectile dysfunction (impotence) in men. Buy Viagra 50mg It works by increasing blood to the penis This helps men to get or maintain an erection. It belongs to a group of medicines known as phosphodiester type5 (PDE 5) inhibitors. Viagra 50mg tablet may be taken on an empty stomach or with a meal. You should take about 1 hour before you plan to have sex the amount of time it takes to work varies from person to person , but it normally takes between 30 min and 1 hour.