Change, pause or cancel your subscription anytime. This will increase the supply of blood to the lungs and reduce the workload of the heart. To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you. Without physical action to the penis, such as that occurring during sexual intercourse, sildenafil will not work to cause an erection. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil . Sildenafil under the name Viagra is used to treat erectile dysfunction (impotence) in . Sildenafil is used to treat male sexual function problems (impotence or erectile .