Penile Injection Testing


Intracavernous injection therapy (penile injection therapy)

The process whereby a small amount of a chemical is injected directly into the corpora cavernosa (the cavity in the penis that fills up with blood causing a rigid erection). These chemicals are smooth muscle relaxants and thus help increase blood flow into the penile vessels.  The advantage of this treatment is that it is reversible and less invasive than surgery.  The disadvantage is that it is not spontaneous and the erection does not go away until the medicine wears off even if you climax or orgasm.  There is a risk of priapism or prolonged erection which can be a medical emergency.  For this reason the initial testing is performed in the office so that an antidote can be given if too strong a dose is given.  Patients should see emergent medical treatment for an erection lasting longer than 4 hours.

Frequently Asked Questions

How is the medication Injected?


The medication is injected along either lateral side of the penis. First, the medication is drawn into a syringe, usually an insulin-type syringe with a short, very fine needle. The medication is given into the spongy tissue of the penis, called the corpora cavernosa.

After choosing the proper site to inject on your penis, clean it with an alcohol wipe, “poke” the needle through the skin of the penis, and then inject the medication into the penis. Immediately afterwards, press firmly on the injection site with either an alcohol pad or gauze with your thumb and first finger to compress the area for at least five minutes or up to 10 minutes for patients taking blood thinning medication, such as coumadin.

The medication tends to work better if you stand, as it allows more blood to go to your penis. Also, external stimulation to the penis increases blood flow to the penis and allows the medication to take effect faster.

Some people prefer the auto-injector, which is a spring-loaded device that inserts the needle into the penis very quickly, minimizing discomfort and psychological “hesitancy.” It comes in two forms: a simple, non-prescription device designed to insert the needle for you, and a prescription device that also depresses the plunger for you.