Erectile dysfunction (ED) is a condition in which it’s difficult to get or keep an erection firm enough to have sex.

There are many ways to treat ED, including lifestyle changes, psychotherapy, oral medications, surgical procedures, and penile injection therapy, or intracavernosal injection therapy.

Penile injections can generally be self-administered at home. They help treat ED by improving blood flow to the penis, which leads to firmer erections.

While the thought of injecting a needle into your penis may make you cringe, a 2019 review found that penile injection therapy is generally an effective and well-tolerated treatment for ED.

Your first two injections should be done by your doctor. During your visit, they’ll show you how to do the injections at home.

The first step is to wash your hands and assemble your supplies on a clean surface. You’ll need:

  • 1 medication vial
  • 1 sterile syringe
  • 2 alcohol wipes
  • 1 sharps container for used syringes. It’s best to use a container that’s been approved by the Food and Drug Administration (FDA). If you don’t have access to one, you can use a sturdy plastic container, such as an empty detergent bottle with a cap.

Once the medication is in the syringe, gently grasp the head of your penis between your thumb and forefinger and pull it straight out in front of you. If you’re not circumcised, pull the foreskin back before grasping the head.

Find an area in the middle of the penis shaft, on the right or left side, to inject. Alternating sides each time you inject can help you avoid developing scar tissue. Be sure to avoid an area with a visible blood vessel.

Once you’ve selected an area, clean it with an alcohol wipe. Let go of the head of your penis and pick up the syringe with both hands.

Remove the cap on the syringe, and make sure the dose is correct and there are no bubbles in the syringe. With one hand, hold the syringe between your thumb and your index and middle fingers, as though you were about to throw a dart.

Using the other hand, pull the head of the penis out in front of you again. Be careful to hold only the head, so you’re not pulling any skin along the shaft.

Place the needle against the skin in the chosen area and slide the needle into the shaft. The needle should be at a slight angle, with the plunger facing up at the 10 or 2 o’clock positions. Adjust your hand so your thumb or index finger can push the plunger.

Push the plunger quickly so that all the medication is released. Once the syringe is empty, quickly pull the needle straight out. Apply gentle, but firm pressure on the injection site with your thumb and your index finger on the opposite side of the shaft. Do this for 2 or 3 minutes to avoid any bleeding or bruising.

Put the syringe in the sharps container for disposal.

In general, an erection should follow an injection within 5 to 15 minutes. However, some men may need sexual foreplay to achieve an erection. The erection should last about 30 to 60 minutes, though this will vary depending on your overall health and other factors.

Some men report that injections affect the sensation in their penis and their ability to ejaculate. However, these effects may be due to whatever is causing ED rather than the injections themselves.

The three main types of medications used in penile injection therapy include:

  • papaverine
  • phentolamine
  • prostaglandin E1 (PGE1) or alprostadil (Caverject, Edex, MUSE)

Sometimes, only one medication is administered. But combinations of these medications are also widely used. Combination medications include BiMix, which is papaverine and phentolamine, and Trimix, which contains all three medications.

All these medications work by relaxing the smooth muscles and widening the blood vessels in your penis. This increases circulation and leads to an erection.

Penile injection therapy is considered an established and effective second-line therapy for ED. That means it’s generally prescribed only if first-line therapy — oral ED medications — are ineffective or not well tolerated.

Some men don’t like the side effects of oral ED drugs, which can include:

  • congestion
  • headache
  • upset stomach
  • flushing
  • back pain

Some men may also prefer injection therapy over other ED treatments, such as having penile implant surgery and the risks and potential side effects that can accompany that approach.

A 2019 study of 105 men found that about 70 percent of men who relied on penile injection therapy for more than 8 years were satisfied with the results.

That’s not to say that ED injections are risk-free. As with any type of injection, there’s a slight risk of bleeding or bruising at the injection site. But if you’re careful and follow your doctor’s instructions, these problems may be avoidable.

Proper placement of the needle can help avoid temporary irritation and swelling.

Some men also report mild pain after injecting.

In rare cases, priapism — a prolonged erection that occurs without, or long after, sexual stimulation — may occur. To treat priapism, try applying an ice pack to your penis. Taking a decongestant containing phenylephrine may help, too. However, if the erection lasts longer than 4 hours, seek immediate medical attention.

Likewise, if you’re experiencing pain or any bleeding that lasts more than a couple of minutes after the injection, see a doctor immediately.

Medications for penile injection therapy are available with a prescription, and sometimes they’re covered by insurance. For example, men who develop ED after prostate cancer treatment may be eligible for coverage. Check with your insurance carrier to find out if you’re covered.

Though some oral ED medications are now available in generic form, they can still cost $10 to $20 or more per dose, according to estimates on

Depending on the dosage your doctor recommends, injectable medication may be as little as $5 per dose, according to This means that injection therapy may be cheaper, if not somewhat riskier, than oral medications.

Your doctor can write you a prescription for an injectable medication after you’ve been diagnosed with ED. Depending on your unique situation, your doctor may have you try oral medications before trying injectable medications.

Once you have a prescription, you should be able to fill it at your local pharmacy. In some cases, you may also be able to fill it online. However, it’s important to know that buying any kind of medication over the internet carries some risk.

To be safe with this approach, check with your state board of pharmacy to see if the pharmacy you’re buying from is licensed. You should also make sure that you’re ordering FDA-approved drugs and that a licensed pharmacist is available to answer your questions.

Keep in mind that a valid pharmacy will require a prescription to purchase medications.

Penile injection therapy is used by men of all ages to treat ED with a variety of causes. It can be used long term, though you’ll want to vary injection sites each time you inject. This helps avoid creating any scar tissue.

To achieve the best results, learn as much as you can about the process from your doctor, and don’t hesitate to ask them questions about side effects, dose, or any other topic.

Getting the right dose may take a little trial and error, but if you’re willing to put in the time and effort, good results are possible.