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Erectile Dysfunction Injections

Penile Injections to Treat Erectile Dysfunciton


Updated October 16, 2011

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Penile injections are one of the older methods of erectile dysfunction treatment. This treatment involves injecting medication directly into the penis, which produces increased blood flow into the penis and subsequently, an erection. There are currently three different drugs commonly used in penile injection treatment for erectile dysfunction: prostaglandin E1, phentolamine, and papaverine. Each is thought to work in a different way, but produce the same results.

How They Work
All three drugs function in a similar fashion to other erectile dysfunction drugs by encouraging and/or allowing greater blood flow in the penis, and subsequently, a restriction of blood out of the penis, thus producing an erection. Some medications requires refrigeration and mixing prior to injection; some don't. You should not use any penile injection treatment without getting instructions from a health care provider. Penile injections may produce erections without stimulation of the penis, although stimulation is recommended. Erections can occur between 5 and 20 minutes after injection, and shouldn't last longer than one hour.

Penile injections should not be used more than once in a 24-hour period, and no more than three times a week. Injections should not be used by men with sickle cell anemia, leukemia, bone marrow tumors, penile implants, abnormalities, or conditions that may result in long-lasting erections.

How Effective are Erectile Dysfunction Injections?
When talking about the effectiveness of treatment for erectile dysfunction we need to specify what effective means. Is the goal just to produce an erection? Is the goal to be able to feel sexual pleasure, or increase sexual pleasure? Most research only focuses on erections, and the question that is asked (which is a bit problematic) is whether or not the man was able to have an erection that allowed for intercourse.

Based on this measure, trial data from one of the most popular brands of erectile dysfunction injection, Caverject, indicates that it works as often as 80% of the time. In one six-month study of 683 men, the men reported being able to have sexual intercourse 94% of the time they used injections. In a five-year study of men who experienced erectile dysfunction following radical prostatectomy, 26% found that penile injections didn't help at all, 42% said they helped somewhat, and 28% said they helped a lot. Of those men who found penile injections worked for them, 27% said they produced erections firm enough for intercourse.

Side Effects
All medications come with some side effects, and much depends on the individual. If you are experiencing any side effects that your doctor did not mention initially, you should let them know so they can make sure it isn't a warning sign of a more serious interaction.

Common side effects of penile injections differ based on the specific medication, but may include:

  • pain after injection
  • minor bleeding at the site of injection
  • development of scar tissue around the site of the injection

Other side effects include:

  • facial flushing
  • headache
  • dizziness
  • prolonged erection

Note that if there is bleeding, this can increase the risk of transmission of disease during any contact between the penis and the mouth, vagina, or anus. For this reason, using condoms may be advisable when using penile injections.

With any erectile dysfunction treatment, if you experience an erection for longer than four hours, you should go to an emergency room and/or seek immediate medical attention.

Where to Get Erectile Dysfunction Injection Medication
Before using any medication to treat erectile dysfunction, you should see a doctor for a physical exam and speak with them about your options and what treatment would be safest for you. You should not attempt to use penile injections without receiving instruction from a healthcare provider. It is recommended that they observe you self-injecting at least once, so that they can be sure you're doing it correctly and also watch for any immediate negative reaction.

While there are many places where you can buy erectile dysfunction medications online, and some may seem like a significant savings, it's recommended that you only purchase medications from a company you know and trust. Many of the offers online are outright scams, and others may send you medication that is not what they promised.

Before Trying Penile Injections
Erectile dysfunction is a known early warning sign for other potentially serious health problems. It may be your body's way of telling you that something else is going on. If you are experiencing difficulty with erections, the first step should be to speak with a doctor. Particularly with penile injections, but really with any treatment you are considering, including those labeled as "natural," you should talk to a qualified and trusted health care provider before trying it.


Eardley, I., Donatucci, C., Corbin, J., et. al. "Pharmacotherapy for Erectile Dysfunction" Journal of Sexual Medicine Vol. 7 (2010): 524-540.

Linet, O.I., and Ogrinc, F.G. "Efficacy and Safety of Intracavernosal Alprostadil in Men with Erectile Dysfunction" New England Journal of Medicine Vol. 334, No. 14 (1996): 873-877.

Penson, D.F., McLerran D., Feng Z, et. al. "5-Year Urinary and Sexual Outcomes After Radical Prostatectomy: Results From the Prostate Cancer Outcomes Study". Journal of Urology Vol. 173 (2005): 1701–5.

Pfizer: Caverject Patient Information.

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