What are Corpus Cavernosa Injections, or Intracavernosal Injections?

Penis injections are used for medical exams and erectile dysfunction

Corpus cavernosa injections are used to both diagnose and treat erectile dysfunction. They are also used in the diagnosis and treatment of other types of penis problems, such as Peyronie's disease. Also known as penile injections, intracavernous injections, and intracavernosal injections, the injected medicine increases the flow of blood into the corpus cavernosa of the penis. This causes the penis to become erect. Or, if the penis does not become erect, it allows the healthcare provider to identify that there may be underlying issues with blood flow.

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Purpose of Penile Injection

The purpose of a penile injection, when used as a diagnostic tool, is to look for problems with penis health. One of its major purposes is to help healthcare providers determine whether there is an underlying reason why a man reports problems getting, or sustaining, an erection firm enough for penetrative sex. It can also be used in the diagnosis of men who report pain during erections or penile curvature. For each of these concerns, it is helpful for the healthcare provider to be able to examine the erect penis.

In order for a man to have an erection, there must be sufficient blood flow into the penis for it to become erect. Furthermore, the swelling of the erectile bodies must put enough pressure on the veins of the penis to prevent the blood from leaking out. During sexual activity, stimulation increases blood flow into the penis.

Penile injections remove the potential psychological barriers to getting an erection during a medical exam. It optimizes the process of getting an erection, and erectile function, by directly stimulating blood flow into the penis. When combined with the use of penile Doppler ultrasound, and sometimes other imaging techniques, penile injections allow medical professionals to determine if erectile problems have an underlying biological cause or are more likely to be caused by relational or mental health concerns. They also make it possible to diagnose penile curvature.

Due to the development of oral PDE-5 inhibitors such as Viagra, it has become less common to use penile injections as a diagnostic tool. Some studies have suggested that penile injections remain a more effective way to diagnose erectile problems than oral medications, but many providers and men prefer to start with the less invasive option. That said, when moving out of diagnosis and into treatment, some men actually prefer injections to pills. For others, injections remain the most effective option. In particular, direct or indirect stimulation is often required to get an erection after PDE-5 use. This may make oral medication less suitable for men who have undergone pelvic surgery, such as radical prostatectomy without nerve-sparing, and who lack good penile sensation.

Risks and Contraindications

Individuals with untreated coagulation disorders should not be given intracavernosal injections. Healthcare providers may also be reluctant to use these injections for individuals with sickle cell anemia and certain types of blood cancers. However, for those patients concerns are more likely to be about penile injections as treatment rather than as a diagnostic test.

The major risk of penile injection is priapism, a prolonged and painful erection. Left unaddressed, an erection that lasts more than four hours can damage the penis. Complications of priapism are unlikely with diagnostic use of intracavernosal injection, as the healthcare provider can address blood flow issues before the patient leaves.

Other minor risks include swelling, bruising, or pain around the site of injection.

Before the Test

Intracavernosal injection is not usually the first test when a man expresses concerns about erectile function or penile curvature. Initially, the healthcare provider may examine the penis and ask questions about erectile function or use a self-report measure. They may also perform blood tests to look for underlying health concerns, such as diabetes or heart disease, that can affect erectile function, or ask questions about the health of a relationship. Depending on what the healthcare provider finds, they may recommend a penile injection test, or they may recommend starting out by trying oral PDE-5 inhibitor medications at home.

If a penile injection is indicated, this will usually be done in a healthcare provider's office that specializes in sexual health. Depending on the indications for the test, an ultrasound may also be arranged for the same time.

There are no special preparations required for this test.

During the Test

Erection testing with penile injection is done by your healthcare provider. You will usually be asked to disrobe from the waist down and put on a gown. Then the skin of the penis will be swabbed with alcohol, and a fine needle will be inserted. The intercavernosal injection will be performed with this needle. You should expect to feel a small pinch, but it is usually not a painful experience.

Depending on the drug used, the healthcare provider may offer you visual stimulation material, such as erotic magazines, in order to help you get an erection. They may step out of the room to give you privacy and to allow your penis time to become erect. You should expect to experience an erection within 5 to 15 minutes.

After your penis has become erect, your healthcare provider will examine it. They will look for curvature or areas with dents or other deformities. They may also use an ultrasound to check for the health of blood flow into the penis and to measure how quickly blood is flowing out of the penis. If an ultrasound is used, this should not be painful. A gel will be placed on your penis and then the machine will use sound waves to show the structures inside the penis and to measure blood flow. Ultrasound testing may be performed by either your healthcare provider or a specially trained ultrasound technician.

If you do not get an erection during the test, this may indicate that there are problems with the blood flow into or out of your penis. The healthcare provider can examine blood flow with ultrasound, even without a full erection. In cases where ultrasound has detected possible issues with the arteries and veins supplying the penis, an angiogram may be recommended. However, this is a more invasive test that is usually only used if men are potential candidates for revascularization—surgical repair of the blood supply of the penis.

You will generally be kept in the healthcare provider's office until your erection subsides. This should take place within 30 minutes. At this point, if ultrasound has been used, you can clean the gel off your penis and get dressed. If no ultrasound was done, you should be able to just get dressed.

After the Test

You should be able to return to your day, as normal, after the test. Pain, swelling, or bruising at the injection site can occur, but is usually mild.

If you experience an erection lasting more than 4 hours after a penile injection, you should see a healthcare provider immediately or go to your nearest emergency room.

Interpreting Results

If you are able to get a firm erection after a penile injection, that means that your body is able to keep sufficient blood in the penis. However, you may still have issues getting sufficient blood into the penis without the help of medication. Possible diagnostic results from an intracavernosal injection test include:

  • Peyronie's disease, a diagnosis of penile curvature.
  • Arterial insufficiency, which means that there is not sufficient blood flow into the penis. This can be caused by cardiovascular disease, penile injury, or surgeries performed on the prostate, including radical prostatectomy for cancer.
  • Venous leak, or poor venous occlusion. This means that your body is unable to keep blood from flowing out of your penis. It can be caused by mechanical injury to the penis, underlying cardiovascular disease, or from procedures done on the prostate.

If there are no clear, organic problems affecting your erection, anxiety or relationship concerns may be at the root of erectile dysfunction. That does not make erectile dysfunction any less of a medical problem. However, it offers different options for treatment.


Depending on the results of your test, follow-up will vary. You may be offered a PDE-5 inhibitor as a first-line treatment. If an underlying health condition, such as diabetes or atherosclerosis, seems to be a likely cause of your erectile health concerns, you may be referred for management of that problem as well. If you have Peyronie's disease, you may be offered additional imaging tests to try to detect the cause of your curve. You may also be referred to sex therapy, or other kinds of therapy, if dealing with your penis health has caused you distress or problems in a relationship.

If you have any questions about what your sexual health will look like moving forward, it's important to discuss them with your healthcare provider. That doesn't include just questions about medical issues, such as what your treatment options may be. It can also be helpful to discuss how to talk about your erectile health and treatment with any current or future sexual partners.

A Word From Verywell

It can be scary to experience problems with erectile function or penis health, and even scarier to discuss those problems with a healthcare provider. However, it's important to know that, in most cases, those problems are treatable. There are a growing number of options for treating erectile concerns that range from sex therapy, to taking a pill, to surgery to correct a penile curve, to getting a penile prosthetic. Furthermore, for some men, the penile injections that are used to diagnose their sexual health concerns are also a highly effective therapy.

You should note that there are many "men's health" clinics that are for-profit, are not run by sexual health experts, and charge patients high amounts to perform these types of injection testing. The best approach for these procedures is to visit a urologist that specializes in sexual health, which should allow you to receive the same procedures at a healthcare provider's office and pay with insurance.

If you're waiting on a diagnosis for concerns about the health of your penis, it may help to have someone to talk to. That could be your partner, if you have one, or it could be a therapist. It's important to give yourself permission to ask for help. And, if erectile issues are affecting your sex life, it may be useful to be upfront about that with your partner. After all, a firm erection isn't required for a healthy, exciting sex life, but you don't want anxiety about getting an erection to take all kinds of fun off the table

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Cleveland Clinic. Alprostadil (injection therapy).

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By Elizabeth Boskey, PhD
Elizabeth Boskey, PhD, MPH, CHES, is a social worker, adjunct lecturer, and expert writer in the field of sexually transmitted diseases.