Discreet and FDA-approved ED treatments shipped directly to you. ED (Erectile Dysfunction) medication is used to help men who have difficulty achieving or maintaining an erection. These medications, such as sildenafil (Viagra), tadalafil (Cialis), and others, work by increasing blood flow to the penis during sexual stimulation. They are usually taken before planned sexual activity and should only be used under a doctor’s guidance. ED medication is safe for most healthy men but may not be suitable for those with heart conditions or who take certain other medicines.