Caverject Injection: What It Is and How It Works

For many guys, a properly functioning penis is pretty high on their list of health priorities.

So if you’re dealing with a diagnosis of erectile dysfunction (ED), you may be willing to go to great lengths to make it work. Do those lengths include Caverject^® injections?

There are plenty of harmful products for male performance enhancement (we’re looking at you, gas station sex pills and sketchy supplements). So when people start talking about needles, it makes sense to wonder if this is really the best choice.

Here, we’ll go over the evidence about Caverject injections as a treatment for erectile dysfunction to help you understand how these ED injections work.

While dealing with ED can be difficult, there are (fortunately) quite a few treatment options, including intracavernosal injections. Believe it or not, injectable penile medications are an effective way to maintain an erection.

So, what is Caverject? Also sold as Caverject Impulse^®, Caverject injections consist of a medication called alprostadil, along with inactive ingredients like lactose and sodium citrate. 

Sometimes referred to as prostaglandin E1 or PGE1, alprostadil is designed to help open up your blood vessels better.

This is a good thing in the context of ED. Wider blood vessels increase blood flow to the penis, which helps you achieve and maintain an erection sufficient for satisfactory sexual intercourse.

Alprostadil injections are approved by the U.S. Food and Drug Administration (FDA) for the treatment of erectile dysfunction.

Caverject comes as vials of powder that need to be mixed with a liquid solution before injecting. 

Although it’s a minimally invasive solution, these injections are considered a second line of treatment when lifestyle changes or oral medications don’t work. This is simply due to the added challenge of injecting your penis compared to taking a pill. (This is the main difference when it comes to Caverject vs. Viagra^®, by the way: Both are FDA-approved and effective ED medications, but Viagra is taken orally while Caverject is injected directly into the penis.)

The point of Caverject is that it delivers the vasodilator medication directly to the site where it’s needed. This allows it to start working pretty quickly: An erection may occur within five to 20 minutes after injection, lasting 30 minutes to one hour.

Does Caverject Increase Size? 

No. While Caverject can enhance erection quality, it doesn’t make your penis larger.

While self-injection may seem pretty straightforward, there are a few details about Caverject injections you should know.

Your first injection should be given by a healthcare professional, who’ll then provide you with instructions on how to do the injections yourself, including proper injection technique.

There are a few supplies you’ll need to have on hand, such as:

• Diluent (bacteriostatic water for injection preserved with benzyl alcohol)

• A 1- to 3-milliliter (mL) syringe, depending on your dosage

• Alcohol wipes to sterilize the injection site

• 29- or 30-gauge half-inch needles

Because you’ll use a new needle each time, you may also need a sharps container to safely dispose of them.

Self-Administering Caverject Injections

Proper use of Caverject is essential. Using a fresh, sterile needle, wipe the intracavernosal injection site with an alcohol swab. 

Making sure to avoid veins, use the syringe plunger to administer your prescribed dose. Retract your foreskin if need be, stretch out your penis, and inject on either the right or left side of the shaft.

You don’t want to go too far in. The point is to enter one of the corpora cavernosa (the two chambers of spongy tissue on either side of the penis that fill with blood to achieve an erection).

Compress the site of injection for five minutes or until any bleeding stops. After that, dispose of the needles in a sharps container, and throw away any unused mixture in the syringe.

Caverject injections use superfine needles to deliver the medicine, which can easily bend or warp. If you notice a bent needle or see needle breakage, don’t use it. Throw the damaged needle out and start with a new one.

Bear in mind these are general guidelines — always follow your healthcare provider’s directions to a T.

But wait — what’s considered an effective dose?

A single dose of Caverject can range anywhere from 2.5 to 40 micrograms (mcg). Single-use vials usually contain 20 or 40 micrograms of alprostadil to be injected no more than three times a week.

Your healthcare provider will make a dosage recommendation based on the cause or severity of your ED.

Earlier, we mentioned that Caverject is considered a second-line treatment for erectile dysfunction. That’s partially for convenience (a pill is easier to take than an injection) and partly because typical first-line ED treatments are safer.

Alprostadil is effective in the management of erectile dysfunction. However, it’s by no means a cure and won’t help you return to the spontaneous erectile function or natural erectile function of your youth.

An injection of Caverject might be beneficial for those who shouldn’t use oral ED medications (known as PDE5 inhibitors), prefer not to take pills, or find that PDE5 inhibitors are ineffective.

These injections have been found effective in a wide range of men during clinical trials, including generally healthy guys struggling with ED, those with health conditions like diabetes, and men with spinal cord injuries.

One study found that Caverject injections were especially effective for achieving an erection in men with diabetes and erectile dysfunction. And a review of therapies for ED noted that 94 percent of people were satisfied with their initial treatment with this medication.

The research we have is pretty straightforward: Caverject works. And when administered correctly, you can minimize the risk of side effects.

Of course, no medication is without the possibility of side effects — and Caverject injections are no exception.

Possible side effects of Caverject include:

• Penile pain

• Penile fibrosis (where scar tissue forms in the penis)

• Injection site bruising or hematoma

• Penile numbness, irritation, sensitivity, itching, redness, skin tear, or discoloration

• Penile rash

• Penile edema (swelling caused by fluid buildup)

• Low blood pressure that might lead to fainting

• Allergic reaction

In clinical trials, the most common side effect was penile pain. And there’s a small chance of experiencing angulation (an abnormal bend in the penis) or Peyronie’s disease.

Caverject may also increase the risk of a condition called priapism. This is when an erection lasts more than four hours without any obvious source of physical or mental sexual stimulation.

If you have a medical condition that predisposes you to priapism, like multiple myeloma, leukemia, or sickle cell anemia, your healthcare provider may recommend a different ED treatment.

If your erection lasts more than four hours or you’re experiencing a painful erection, seek medical attention right away.

Always follow the instructions for use, keep Caverject out of reach of children, and pay attention to any odd side effects that may develop.

Practically speaking, the reason you may not have heard much about this medication is that there are other effective and less intrusive medications to improve sexual activity — ones you can just swallow (or chew if you enjoy hard mints).

These PDE5 (phosphodiesterase type -5) inhibitor medications also increase blood flow to the penis but are less invasive.

The most common PDE5 inhibitors include:

• Sildenafil (Viagra)

• Tadalafil (Cialis^®)

• Vardenafil (Levitra^®)

• Avanafil (Stendra^®)

Viagra is the one you’ve most likely heard of before. It’s a popular choice, thanks to its relatively low risk of side effects. 

Here’s the breakdown of Caverject vs. Viagra for ED:

Non-Medication Alternatives to Caverject

Before or in addition to medications, your healthcare provider may suggest healthy lifestyle changes to help with ED, including eating a nutritious diet, staying physically active, losing weight if you’re overweight, managing stress, and quitting smoking.

While these changes and PDE5 drugs are often most effective for physical causes of erectile dysfunction, there’s a chance you’re dealing with psychological ED. 

The psychological causes of erectile dysfunction include mental health conditions like depression, relationship problems, and sexual performance anxiety, among others.

If this is the case, you may want to talk to a licensed mental health professional, either in person or through online therapy. They can help you identify what’s causing your stress or anxiety and find ways to manage your mental health.

Other erectile dysfunction treatments include vacuum erection devices and penile implants.

Although it’s a prevalent problem affecting many men, you don’t have to live with erectile dysfunction. Plenty of solutions are available, including Caverject injections.

Here’s what to remember about this ED treatment:

• Known as intracavernosal alprostadil and sold under the brand name Caverject, this medication is injected into the penis to help produce an erection relatively quickly.

• While this treatment is typically well-tolerated, the most common side effect is penile pain. Other possible side effects include prolonged erections lasting more than four hours.

• While Caverject is not a typical first-line ED treatment (lifestyle changes and oral ED medication are), some men use Caverject as an effective option if first-line treatments aren’t effective or appropriate.

Knowing the possible underlying cause of your sexual dysfunction can help a medical professional figure out the best treatment options for you. Healthcare providers can offer personalized medical advice and will often recommend lifestyle modifications and possible erectile dysfunction medications.

To access medical guidance and ED treatments online, check out our sexual health telehealth platform.