Your urologist may give you a medication that you inject yourself and which works for men with a wide range of medical conditions. You will inject the medication directly into the side of the penis, and it will create an erection by dilating blood vessels and relaxing the spongy tissue. An erection is produced after 5 to 15 minutes from the time of the injection, and will last 30 minutes to an hour, or until orgasm.
The injection is effective for people with severe erectile dysfunction, including those who have had nerve injuries from a prostate operation. The injections should not be given more than 12 times per month, and they should be spaced as evenly as possible within that month.
A doctor usually gives the first injection, which is used both for diagnosis and to decide the medication required for a specific patient.