Caverject Injections for ED: A Guide

Katelyn Hagerty

Reviewed by Katelyn Hagerty, FNP

Written by Our Editorial Team

Published 11/28/2022

Updated 11/29/2022

Whether you’re single, married, in an open relationship, gay, straight, bi or you can’t be defined by labels, your penis is probably still pretty high on your list of priorities. If ED is making your high priority bodypart function poorly, you may be willing to go to great lengths to make it work. Do those lengths include Caverject® injections?

You might find it hard to believe an injection (and a needle in any context) could do much good for your penis, especially if it’s already having some trouble performing. Truth be told, we were skeptical too. 

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

We’ve compiled claims and evidence about caverject treatment of erectile dysfunction, and we can help you understand how these intracavernous injections are supposed to work and whether they actually make good on those claims. 

But before we dive into the data, we should get a few basics about this treatment out of the way. Let’s start with the most obvious question: just what is Caverject?

What are Caverject Injections For ED?

Caverject is really just an injectable version of a vasodilator — a medication designed to help your blood vessels better dilate which, in the context of your penis, helps you achieve and maintain an erection sufficient for satisfactory intercourse once you become aroused. 

Essentially, these medications (in the case of Caverject, the active ingredient is called alprostadil) increase the net blood flow to your penis, which results in a full, hard erection in certain circumstances where you might have struggled to maintain an erection previously.

Alprostadil injection is approved by the U.S. Food and Drug Administration (FDA) for the treatment of erectile dysfunction, and the FDA has approved this intracavernosal administration as a way to restore sexual function. 

For the record, alprostadil is considered a second-line medication for erectile dysfunction, meaning that it shouldn’t be used for treatment until other treatment options have been considered, attempted or ruled out. 

Part of the reason for this is simply the comparable difficulty of injecting your penis as compared with taking a pill.

The point of Caverject is that it delivers the vasodilation medication directly to the site where it’s needed. After administration, it can work pretty quickly.

How Do Caverject Injections Work?

Essentially, when taking a Caverject injection, you sit, retract your foreskin if need be, stretch your penis out 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 the corpora cavernosa, which are the two chambers of spongy muscle tissue located on either side of the penis that fill with blood to achieve an erection

Use only a fresh, sterile needle, wipe the intracavernosal injection site with an alcohol swab, avoid veins, use the syringe plunger to administer an effective dose (typically between 20 and 40 micrograms) and compress the injection site for five minutes. After that, cover any loose needles with a needle cover and you’re done.

Your erection should occur within five to 20 minutes after the injection, though it may take longer. People typically see their highest erectile state roughly 30 minutes after the injection, after which your levels of Caverject will slowly return to baseline levels or pre-dose levels. 

In all, the duration of your erection is likely to be around 12 minutes or more.

However, like standard erectile dysfunction medication, if your erection lasts longer than four hours, you should seek medical care immediately.

Are Caverject Injections For ED Effective?

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

That said, alprostadil has been shown effective in the management of erectile dysfunction. It’s by no means a cure, and will not help you return to spontaneous erectile function or natural erectile function. 

Alprostadil injections are also clearly not the most painless way to deliver medication for erectile dysfunction — but they work.

One 1996 study that looked at nearly 300 men found alprostadil to be a safe and effective treatment for ED with mild adverse reactions overall.

A small comparative trial from 1998 involving 30 men compared another vasodilation injection with Caverject and found that Caverject was more effective in achieving an erection and specified that it achieved a “higher grade” of erection than a combination of two other medications: papaverine and phentolamine.

A 2001 study found that the same was true specifically for diabetic men with erectile dysfunction.

While penile injections like Caverject are still technically considered viable options in the treatment of erectile dysfunction, there isn’t as much research on them available at this point because they’ve primarily been replaced by more updated methods.

But, the research we do have is pretty clear — it works and, when administered correctly, is as safe as other injection drugs.

Viagra online

Genuine Viagra® makes it possible

The Side Effects of Caverject Injections: Are They Safe?

The main problems you may encounter when taking Caverject are measuring the single dose (single-dose vials can help you always achieve an optimal dose), getting a sterile needle safely in and out of your penis without the possibility of needle breakage and minimizing the chance of an injection site hemorrhage.

That comparative trial we mentioned earlier? Well, the competitor caused priapism (the medical term for a painful erection lasting hours) and had to be evacuated from the trial to deal with the complication. No such complication was reported with Caverject.

However, the side effects of Caverject include:

  • Headache

  • Dizziness

  • Swelling of the penis (the bad kind)

  • Hypotension/hypertension

  • Penile infections or rash

  • Injuries to the penis

Caverject can cause problems like priapism and penile fibrosis, and can increase certain cardiovascular risks. 

There’s also the not-so-great-but-still-worth-mentioning risk of needle breakage — that’s in addition to the risks of penile pain, testicular pain, injection site hematoma (bruise), rash, edema and other injuries that you really don’t want happening to your penis. 

While many of these risks are smaller or temporary, those cardiovascular issues might heighten existing risks of heart attack, excessive bleeding and low blood pressure. 

As such, tell a healthcare professional about existing heart issues before you take Caverject. You should also mention blood diseases like sickle cell anemia (or the sickle cell trait), penile implants or any anatomical deformation like penile deformities. 

ED treatments, delivered

Generic for Viagra (sildenafil)

The more affordable FDA-approved medication that treats Erectile Dysfunction at a quarter of the cost. 🙌

Generic for Cialis (tadalafil)

Affordable and helps get the job done. Generic Cialis helps you get and maintain your erections through a simple, daily dosage.


The OG Little Blue Pill that made its name as the first prescription Erectile Dysfunction treatment.


Cialis helps you get and keep stronger erections with a daily or as-needed pill.

Alternatives to Caverject Injections

Practically speaking, the reason more tests haven’t been conducted and you haven’t heard much about this medication is because there are other, less intrusive, equally effective medications on the market — ones you can just swallow. 

If you’re speaking to a healthcare provider about erectile dysfunction medication, chances are, you’re talking about a particular class of medications called phosphodiesterase-5 inhibitors (PDE5 inhibitors). 

These medications are also vasodilators but have a different, less invasive mechanism of action. 

Popular PDE5 inhibitors include:

  • Sildenafil (Viagra®)

  • Tadalafil (Cialis®)

  • Avanafil (Stendra®)

  • Vardenafil (Levitra®)

Viagra (also known by the generic sildenafil), which you’ve likely heard of before, is an as-needed medication that you take within a window of about an hour before you plan to have sex. It’s relatively low on side effects, with many of the same risks of side effects we mentioned for Caverject — minus the stabby ones.

Cialis®, meanwhile, is also a safe and effective pill. And some versions of Cialis (also known astadalafil) can be taken as a daily medication so that you can be in fighting shape at any time. And if you swallow a pill wrong, you won’t have to seek medical assistance.

All of these medications are things you can get from a healthcare professional after answering some questions about your health, if they determine they’re right for you.

Sildenafil citrate

Get hard for 95% cheaper than Viagra

Caverject Injections and ED: The Final Word

Whether injections will help you with your ED or not is ultimately not something we can say with certainty. Each individual — like their penis — is unique. And with that comes a certain variability in how treatments for erectile dysfunction will actually play out. 

The best way to find the right treatment is to speak with a healthcare professional who can lead you to the right treatments based on your own health and circumstances. 

They’ll be able to give you a formal diagnosis of erectile dysfunction and make additional suggestions based on your unique needs (which may include medication, weight loss, dietary changes, more exercise or therapy for things like performance anxiety).

If need be, they’ll be able to show you the right gauge needle for this treatment, how to measure the correct dose of alprostadil, how to avoid visible veins and demonstrate appropriate injection techniques and correct injection angle under medical supervision.

If you’re ready to improve your erectile dysfunction, we can help. Our health professionals can help you find the right way to take a stab at this ED problem today — hopefully without the needles.

8 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

  1. Abdallah HM. Comparison of Alprostadil (Caverject) and a combination of vasoactive drugs as local injections for the treatment of erectile dysfunction. Int Urol Nephrol. 1998;30(5):617-20. doi: 10.1007/BF02550556. PMID: 9934808.
  2. Tadalafil: Medlineplus drug information. (n.d.). Retrieved May 01, 2021, from
  3. Highlights of Prescribing Information: Viagra (sildenafil citrate). (n.d.). Retrieved April 4, 2021, from
  4. Jain A, Iqbal OA. Alprostadil. [Updated 2022 Jul 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:
  5. U.S. National Library of Medicine. (n.d.). Alprostadil urogenital: Medlineplus Drug Information. MedlinePlus. Retrieved October 17, 2022, from
  6. Reference ID: 4198338 - Food and Drug Administration. (n.d.). Retrieved October 18, 2022, from
  7. Linet OI, Ogrinc FG. Efficacy and safety of intracavernosal alprostadil in men with erectile dysfunction. The Alprostadil Study Group. N Engl J Med. 1996 Apr 4;334(14):873-7. doi: 10.1056/NEJM199604043341401. PMID: 8596569.
  8. Heaton JP, Lording D, Liu SN, Litonjua AD, Guangwei L, Kim SC, Kim JJ, Zhi-Zhou S, Israr D, Niazi D, Rajatanavin R, Suyono S, Benard F, Casey R, Brock G, Belanger A. Intracavernosal alprostadil is effective for the treatment of erectile dysfunction in diabetic men. Int J Impot Res. 2001 Dec;13(6):317-21. doi: 10.1038/sj.ijir.3900760. PMID: 11918246.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.