These types of medicine include:

• prostaglandin E₁ like Caverject or Edex (most common)
• phentolamine
• papaverine

If you’ve had prostate cancer, bladder cancer, colorectal cancer, or surgery or radiation to the pelvis, this treatment might be the best option for you. Injections can work even if you’ve had your prostate removed and the damage to the nerves that cause erections.

If you’ve had surgery, usually just a small dose of penile injection medicine will give you a firm erection. If you’ve had radiation, you might need a higher dose, as some of your blood vessels may be damaged.

How the injections work

Medicine is injected into the penis about 10 to 15 minutes before you want to have an erection. The medicine makes the penis swell without physical stimulation by causing blood to flow to the area. However, with foreplay or when you are excited about sex, the erection will likely get harder.

The erection usually happens within 10 to 15 minutes of the injection and will last 30 to 60 minutes. The erection may not go down completely, even after an orgasm. If the erection lasts longer than 2 hours after the injection, contact your doctor right away. If you can’t reach your doctor, go to an urgent care centre or emergency room.

The idea of injecting medicine into the penis might not sound appealing, but most people who use penile injections say the pain isn’t too bad. Your doctor will teach you how to do the injection and the first one will be given at the doctor’s office. When using penile injections:

• It’s very important to do the injection the way your doctor taught you: on the side of the penis, towards the bottom. The needle is put right into the penis at a 90° angle.
• Only use injection needles 1 time and then throw them away. You can buy needle disposal containers at a drug store or use an old bleach bottle to store them.
• If you’re having trouble injecting yourself, think about asking your partner to learn how to do the injection from your doctor. You can also buy penile auto-injectors, which might make it easier. If you are interested in this, talk to your doctor or healthcare provider.
• It’s important to have support from your partner if you choose this option. It’s also a good idea to have foreplay with your partner after you give the injection.
• If the injection doesn’t work well the first time, wait at least 48 hours and try again.
• Always use the dose of medicine that your doctor tells you to.
• To be successful with using injections, you have to keep trying. You may have to go back to your doctor to ensure you’re using the right technique, or to have your medicine dose adjusted. There are also combinations of medicine that work better for some people. So if the injection doesn’t work the first time, talk to your doctor and keep trying.
• Talk about and make sure your partner understands that you‘re still attracted to them, even though you need the injection to get an erection.
• The medicine must be stored in the fridge, which makes it hard to use if you’re travelling.

Side effects

The most common side effects of the penile injection are:

• aching in the penis (feels like pins and needles)
• a burning feeling in the penis
• bleeding at the injection site, which can cause a bruise (to prevent this, press firmly on the injection site for 5 minutes after the injection)

Sometimes the erection itself may be painful. If you have pain using the injections and it’s within the first 6 months after surgery, you may want to wait a few months to try the injection again. It will likely hurt less the longer it has been since you had your surgery.

Long-term side effects are rare. About 3 to 10 out of 100 men develop scarring on the penis. Mild scarring might feel like small lumps, but severe scarring might make the penis curve with an erection.

Rarely, an erection can last for longer than 4 hours, which is called priapism. If your erection lasts longer than 2 hours after you’ve had sex, see a doctor right away. This might happen if the dose of medicine is too high for you. Do not increase your dose of medicine unless your doctor tells you to. Do not inject more than 1 time a day. It’s best to wait 48 hours between injections.

Where do I get the medicine?

You need a prescription for the medicine and you also need a healthcare provider (like a urologist) to teach you how to inject it. You need a referral from your family doctor or oncologist to see a urologist.

Penile injections are not usually covered by most benefit plans. Talk to your insurance company to find out about your coverage.

Related video

Information about penile injections​ Sexual medicine physician Dr. Stacy Elliot discusses what a penile injection is, demonstrates how it works, and describes the step-by-step process.

​​​