One medication used to treat impotence and erectile dysfunction is called purple pill viagra. sildenafil, a component in this medication, helps men have a firm erection during sexual activity so they may enjoy it for an extended period of time. Men alone, over the age of 18, may use this medication. Take this medication half an hour before sexual activity. While using this medication, avoid eating fatty foods or cold beverages since they will decrease the medication's effectiveness. Follow your doctor's advice when taking this medication.