Penile Injection Therapy for ED
For men who can’t take or don’t respond to oral Erectile Dysfunction (ED) medications, penile injection therapy offers a fast, reliable alternative. At Maze Men’s Health, this treatment uses a tiny, nearly painless injection of medication—such as prostaglandin E1, Bimix, or Trimix—to increase blood flow and produce a natural erection within minutes. Guided by Michael A. Werner, MD, patients are carefully trained to use the injections safely and confidently. With expert dosing and support, more than 90% of men achieve strong, lasting erections, even after failing other ED treatments. Penile injections are safe, effective, and proven to restore performance and confidence for men across Westchester, NYC, Connecticut, and New Jersey.
Penile Injections
What if you can’t take one of the available oral medications or if the medications aren’t working the way you’d like? One of the options available for the treatment of ED is the self-injection of medication into the penis. This often sounds scary to the patient but most men will tell you that the injection doesn’t hurt at all. Some describe it as completely painless. Others report that if feels as if they have been flicked with a rubber band. The injection is extremely quick and uses a very fine needle (usually a 29 or 30 gauge). And since the side of the penis doesn’t have many pain receptors, there is little sensation.
It works like this. The medication goes into the penis with a device that’s similar to the ones used by diabetics. A disposable syringe, with a very fine needle, is placed on the injector. The device is placed against the side of the penis, and you press a button. A spring pushes a very thin needle into the penis and, at the same time, pushes the medication into the penis. Watch our video: How to use the Autoinjector for Penile Injections.
Medications
The three most common medications used for injections are prostaglandin E1, papaverine, and phentolamine. All three act by relaxing the smooth muscles and causing the arteries to dilate, making it possible for blood to get into and be kept in the penis. Prostaglandin E1 received FDA approval in 1996 for ED treatment. It is currently marketed and available in prescription plans under two brand names, Caverject Impulse and Edex. However, all three are available in different combinations and strengths.
Each medication has different characteristics:
- Prostaglandin E1 or Alprostadil
- Prostaglandin E1 is a powder that is mixed with a fluid prior to use. This is due to the fact that it is stable as a powder at room temperature, but not as a liquid. Prostaglandin E1 can cause some temporary short-lived aching in the penis. Although it is not medically concerning, it can be uncomfortable. Discomfort is experienced by approximately 20% of patients and is most common in patients who have neurological erectile dysfunction (resulting from, for example, diabetes or post-radical prostatectomy).
- Papaverine and Phentolamine
- Papaverine is a smooth muscle relaxant. It acts directly on the blood vessel walls to relax and thus dilate, as well as activate, the trapping mechanism. It is usually mixed with phentolamine, which is an alpha-blocker that causes smooth muscle relaxation through a different mechanism.
- Papaverine and phentolamine come in liquid form, do not need to be refrigerated, and do not cause aching.
Usually, one of three formulations is used:
- Prostalandin E1 (stable as a powder, but needs to be refrigerated as a liquid.)
- Bimix: is a combination of Papaverine and Phentolamine. It comes as a liquid only, but does not need to be refrigerated. This makes it very convenient for men who travel, or those who don’t want to store their medication in a shared refrigerator. It also never causes any aching.
- Trimix: is a combination of Papaverine, Phentolamine, and ProstaglandinE1. Because it contains PGE1 it needs to be refrigerated and can cause aching in some patients. However, it is often stronger than an equivalent dosage of Bimix (papaverine and phentolamine alone), and thus is often used.
Frequently Asked Questions
How do I learn to do the injections?
Learning how to use the injections, though intimidating, is actually quite straightforward. It is important that your practitioner schedules you for several visits, both to teach you how to do the injections comfortably, and to figure out the right dosage.
At Maze, this usually takes three visits. At the first visit you receive your first injection, to introduce you to them, and to see how you respond. Based on your experience, you can decide whether or not you would like to continue with them.
At your second visit, you will receive a second injection (the dosage of which is based on your response to your first injection). You will also be supplied with the auto injector and taught how to use it. You will be strongly encouraged to practice it (empty-no syringe) at home.
On your third visit, you will give yourself an injection under our observation. By then, we will have figured out the right dosage and medication, based on your responses to the previous two injections. You are then usually sent home with five preloaded syringes, sometimes of increasing dosages to use at home.
Some men need more practice and coaching than others. Rest assured that we will work with you for as long as it takes to get you comfortable with the technique.
How good will my erection be?
Our goal is for you to achieve a great erection that can last as long as you want (up to two hours). If you have a problem with your trapping mechanism, this may not be possible, but it is what most of our patients achieve. We are successful in getting about 90% of our patients, many of whom have failed with pills and injections at other centers, great erections.
If I have already failed injections somewhere else, can you help me?
It is extraordinarily frustrating for us how poorly penile self-injections are managed by “shot clinics” and non-specialists. We estimate that 80% of men who have failed injections at other practices, are successful at ours. This is because we have the expertise and take the time to ensure that each patient has the right equipment, training, and dosages he needs to succeed.
What are the possible complications of penile self-injections?
There are two potential complications, but they are rare if patients are taught how to inject properly and follow the dosages prescribed.
The first is a prolonged erection, or “priapism.” When you have a rigid erection, you are trapping the blood in your penis. This causes pressure, which makes your penis hard but also acts like a tourniquet around your penile arteries, shutting off the flow. This prevents fresh blood from coming into the penis. When your erection goes down, the arteries then can bring fresh blood into your penis. If the erection remains rigid for too long, you are not getting fresh blood into your penis. This is why we ask patients to call us if their erections last more than four hours. If left untreated for too long, a priapism can cause permanent damage. However, this is extremely rare, especially if the dosage is right and you don’t abuse it. If it happens, a priapism can almost always be taken care of in the office.
The second potential complication is developing scar tissue of the lining of the penis. This is also uncommon, particularly if you are taught the right technique. It is important that you vary the site in the penis and that you compress the site for five minutes after the injection. This prevents bleeding on the inside, which can cause scar tissue. This is, of course, part of what we teach you.
How long have penile injections been around?
Penile injections were developed in 1983 and were the second method developed for the treatment of erectile dysfunction. They thus predated the pills by more than a decade. Viagra was the first pill and was approved March 29, 1998.
How do I maintain spontaneity while using the injections?
In some ways, the injection is a more spontaneous solution for treating ED than oral medications since it can be used right before a sexual encounter.
Also, in our experience people vastly prefer excellent sex to spontaneous sex. There are very few periods in a person’s life where sex can be regularly spontaneous. Working around parents and siblings, roommates, and then children means that people generally put far more planning into having sex than they think.
Will my body get used to the injections to the point where they stop working?
There are certain drugs to which the body routinely builds up a tolerance, requiring more and more to achieve the same effects. This is called “tachyphylaxis.” Fortunately, this does not happen with these injections. In fact we often see that when men start using the injections, their own erections (when not using an injection) improve. This is probably a combination of physical changes to the penis ( which is both stretched and getting more oxygen) and more confidence. However, some men need somewhat higher doses as they age, just due to the natural aging process. The vast majority of men are able to use the injections for the duration of their whole sexual life.