Viagra 50 mg pill treats the symptoms of ED, but it’s not a cure for the condition. ED is the persistent inability to achieve and maintain an erection firm enough for satisfactory sexual intercourse. For Viagra to work, sexual stimulation is necessary. Viagra 50 mg pillis rapidly absorbed and usually works within an hour. Thus it is recommended to be taken an hour before any planned sexual encounter. However, it can start working within 30 minutes or take up to two hours to work for some individuals.