Viagra (sildenafil) will help you to treat erectile dysfunction if you have been diagnosed with this condition. Erectile dysfunction not only affects your health and self-esteem - it can also have an impact on your personal relations and even your professional career. Before you start taking this medicine make sure you discuss everything with your health care provider. You need to remember that taking Viagra will not cure your erectile dysfunction, especially if it was caused by physical reasons. Viagra is just a treatment, as its effects are purely physiological. Unless your doctor told you otherwise you are supposed to take Viagra about 30 minutes before having sex to provide for maximum efficiency. Do not take this medicine more often than every 24 hours to avoid dangerous side effects.