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from the injections menu

Some Questions and Answers About Injections

This is not medical advice or an endorsement of any product or method. It is from the FAQ on impotence, from the newsgroup Web site which covers more issues than those created by prostate cancer but is still a resource. Do not abide by or rely upon any single lay opinion. Takes these issues to and consult your physician.)

I've heard about penile injections for ED.  What's this all about?

There are several drugs which can be injected directly into the erectile tissues of the penis to cause an erection.

Before you run screaming at the idea of sticking a needle in your dick, be assured that the injections are made with a very fine needle (the type normally used for insulin) and are less painful than a flu shot.  The following questions discuss the various drugs and how they're used.

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What is Caverject?

Caverject is the trade name for an injectable solution of prostaglandin E1 (PGE1) or alprostadil, which is manufactured by Pharmacia-Upjohn. There are other variants of this including Edex, a similar product from Schwarz-Pharma.

Caverject makes the shot kit. (Do a Internet search for 'Caverject') It is portable and does not require refrigeration until you mix the ingredients.  It's expensive, compared to the PGE1 or PPP (Prostaglandin, Papaverine and Phentolamine). A popular complaint is that the needle is very large. Many here will tell you to purchase the small needles that diabetics use for insulin injections. Mix your powder and liquid using the large needle supplied with the kit, then change to the small needle for the injection. The reason the company supplies large needles may be the worry you might break off the needle in your dick and sue them.

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 What are Bimix and Trimix injectables? 

Bimix and Trimix are injectables for intracavernosal administration. They refer to any combination of either two or three chemicals. Bimix is often a mixture of papaverine and phentolamine, while Trimix (PPP) would add PGE1. Other cocktails are used, mainly in Europe.

These mixtures are not commercially available but must be mixed by a compounding pharmacy.  They are generally much cheaper than Caverject or Edex, and tend to minimize aching in the penis or testicles which is a problem in some men with Prostaglandin (PGE-1) alone.  A compounding pharmacy is one which will create custom medications on a doctor's prescription; it usually doesn't include the corner drugstore or large chain pharmacies.

If you need to find a compounding pharmacy close to where you live, you can go to the International Academy of Compounding Pharmacists at .  You can fill in a form on the site and they'll mail you a list of pharmacies in your area.

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My urologist says he's going to try me on injections my next visit.  What should I expect?

Either the doctor or a nurse will inject your penis with a test dose of the chosen medication and observe the reaction.  Since different men react in varying degrees to the same dose, this is to establish what's the correct dosage for you.  The doctor or nurse will also show you how to administer the shots yourself.  Depending on your penis's reaction to the test dosage the doctor will write you a prescription showing a higher, a lower or the same dosage for home use.  

When you inject at home you may get a different reaction than you did in the doctor's office.  That's because the environment is different;  you may be more or less relaxed or apprehensive.  You can adjust the dosage upwards or downwards in small increments until you find the right dosage for you.  The danger of too large a dose is that you may get an erection that refuses to go down.  This is called Priapism and if it goes on for more than three hours you should contact your doctor immediately.  Priapism can be serious.

[P5 Webmaster note: The danger is that if blood is not allowed to circulate in any tissue oro portino of the body within a certain period of time, that blood and the tissue can "die." See question further down.]

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Do the shots hurt?  

Less than in your arm. The small needles, combined with the soft tissue, makes it go in easy. It's just a little unnerving the first time. And the first time is usually done by a Dr. in their office.

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How do I give myself an injection?  

A diagram usually comes with the medicine. One says to lay your dick to one side, against your body, and shoot into it. Another has you hold it out. The idea is to inject into the corpora cavernosa; the tubes on each side of your dick. Going into the side at about the 9 o'clock to 11 o'clock, or, 1 o'clock to 3 o'clock position. This way you miss the urethra. Anywhere from the base of your dick (next to your body) to about ¾ of the length. Don't shoot in the head (ouch!)

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What about the possibility of scarring?  

The understanding is that there's a possibility that Prostaglandin (PGE1) can cause scarring, (fibrosis) with long-term use. Several men in the newsgroup, however, have used injections for years with no adverse effects. There seems to be less risk with Trimix.  Penile fibrosis can lead to Peyronie's disease or "bent penis".

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Will the shots give me a 100% erection by themselves?

They can, but in practice the shot alone should give you about an 80% erection. Stimulation should bring it the rest of the way up. If the shot alone gives you a 100% erection, you may have an erection for a longer time than you want. Many have received a shot in the doctor's office and had little to nothing happen. Yet when they inject at home, in a situation where they began having sex, it worked. 

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What is the medicine in the shots?  

Most doctors start you out with PGE1 . This is Prostaglandin E1 (AKA Alprostadil) and is the ingredient in Caverject and Edex.  If this doesn't work the doctor may prescribe  Tri-mix, which is a mixture of Prostaglandin, Papaverine and Phentolamine.  A typical mix,  in one bottle, is: Prostaglandin, .05ml; phentolamine, .55ml; Papaverine, 2.5ml; Saline, 1.2ml.

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Can I use my injectables intravenously to get better effect?  

In a word, NO.  It would be inadvisable to do this and may be positively dangerous. Certainly with Trimix, side-effects are minimized by the fact that you are applying the drug intracavernously and are, in fact, localizing the effects of the drug to the corporal tissue. To give the drug intravenously would be likely to cause serious systemic side-effects.

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What about Priapism (an erection that won't go down)?  I've heard it can be a problem with injections.

This can be a problem, especially of you take too large a dose.  It's unlikely to happen if you follow the injection guidelines your doctor gave you and increase or decrease dosage in small steps until you find the right dosage for you.  Your doctor should definitely have given you specific instructions about what to do in case this happens. If not, then be sure to ask about it!  This will normally involve a prescription which you should have filled and on hand, and instructions about either calling the doctor or going to the emergency room if the prescription doesn't work.

In general, you should be concerned about any erection that lasts for more than about 3 hours (but follow your doctor's advice about this).  We're talking about a hard, steady erection here; not one that comes and goes.  The problem is that with a very hard erection, there is virtually no blood flow through the penis, since the veins that carry blood away are shut off tight.  Blood flows in but can't leave.  All the oxygen in the blood captured in the penis is used up and the blood stagnates and thickens, making it even harder for it to be removed by any veins that are still open. If this goes on too long it can cause permanent damage to the erectile tissues. 

In extreme cases you might have to go to a hospital or doctor's office for treatment.  The treatment may involve injection of antihistamines, caffeine or adrenaline directly into your penis, or "bleeding" your penis to remove stagnant blood.


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This information is provided for educational purposes only and does not replace or amend professional medical advice. Unless otherwise stated and credited, the content of Phoenix5 (P5) is by and the opinion of and copyright © 2000 Robert Vaughn Young. All Rights Reserved. P5 is at <>. P5's policy regarding privacy and right to reprint are at <>.