Here's how Levitra works: When a man becomes erect, the arteries in his penis carry blood through the spongy tissue inside. When a health problem keeps genital blood from flowing properly, vardenafil increases blood flow to the penis, resulting in an erection. This increased blood flow to the penis makes Levitra effective for treating the symptoms of erectile dysfunction, including helping a man to get and maintain an erection. Levitra is available in two point five, five, ten, and twenty milligram tablets. Levitra should be taken as needed about sixty minutes before sexual activity. Never take this medication more than once a day.