Penile Injection Therapy

About Penile Injection Therapy

The tissue that causes you to get an erection (erectile tissue) is a muscle. Going long periods of time without an erection is unhealthy for erectile tissue and may damage it.

We believe that having erections keeps erectile tissue healthy. A penile injection helps you have an erection. It works best if it’s given about 5 to 15 minutes before you want an erection.

Giving Yourself the Injection

Do not take the following medications within 18 hours of injecting (before or after):

  • Sildenafil (Viagra®) – 20 mg to 100 mg
  • Vardenafil (Levitra®) – 10 mg to 20 mg
  • Avanafil (Stendra®) – 50 mg to 200 mg

If you take tadalafil (Cialis®) 10 mg or 20 mg, do not inject within 72 hours (3 days) of taking the medication.

If you are using tadalafil (Cialis) 5 mg daily, ask your APP how you should use this medication along with your injections.


The 3 most commonly used medications for injection therapy are Trimix, Bimix, and Papaverine. Most men begin injection therapy with Trimix, which is a mixture of 3 ingredients: alprostadil, phentolamine, and papaverine. These ingredients work by relaxing the smooth muscle and opening the blood vessels in your penis, causing an erection. Your APP will decide whether Trimix or a different medication is best for you.

Storing your medication

The alprostadil in Trimix can weaken over time, so Trimix should be stored in the refrigerator and away from light. This can keep the medication good for a few additional months. If you’re using Bimix or papaverine, you don’t need to keep the medication in your refrigerator because these medications don’t contain alprostadil.

Don’t use the medication if:
  • It has particles or is cloudy.
  • The rubber stopper comes off of the vial.

After your second training visit, your medication will be delivered directly to your home from the compounding pharmacy (specialized pharmacy). Call the compounding pharmacy to make arrangements for billing and shipping. This will limit delays in delivery.

Call your APP when you need a new prescription.

Preparing the injection

  1. Prepare a clean surface for your supplies.
  2. Gather your supplies:
    • 1 medication vial
    • 1 syringe (one-time use only)
    • 2 alcohol wipes
    • Sharps container. You can use an empty detergent or bleach bottle with a cap, or a metal coffee can with a plastic top.
  3. Wash your hands well with soap and water.
Drawing up the medication from the vial
  1. If you’re using the medication for the first time, take the cap off. Throw the cap away. Open an alcohol wipe and wipe the rubber stopper on the top of the vial. You must always wipe the rubber stopper with alcohol before you insert the needle. This will kill any bacteria on the rubber stopper.
  2. Take the syringe out of its package. Remove the cap from the needle. Be very careful not to let anything touch the needle. If anything touches the needle, you must throw the entire syringe away in the sharps container and use a new one. This is because it will no longer be sterile.
  3. First, holding the syringe upright so the needle faces the sky, pull the plunger of the syringe back past the dose you were told to inject. Next, push the plunger back up until the top of the plunger (the thin black line closest to the needle) is at the dose you were told to inject.
  4. Turn the syringe downward so the needle is facing the floor. Hold the syringe in your hand like you hold a pen or dart. Hold the syringe close to the needle with your thumb, index (first) and middle (second) fingers. This will keep the needle from bending as you insert it into the rubber stopper. Support the medication vial with your other hand.
  5. Holding the vial upright and the syringe downward, insert the needle through the circle in the center of the rubber stopper. Push the plunger down to inject the air into the vial (see Figure 1). You do this because the vial is pressurized. You must replace the amount of medication you remove from the vial with air.
  6. Turn the vial and syringe upside down (see Figure 2). Hold the syringe with the hand you use to write with and the vial with your other hand. Don’t let go of the vial, or the needle will bend. Make sure the tip of the needle is in the medication. Rotate the syringe so you’re looking at the numbers and lines on the syringe.
Figure 1. Injecting air into the vial
Figure 2. Withdrawing the medication
  1. Pull the plunger down past your prescribed dose. This will help remove any air bubbles. Slowly push the plunger back up to your prescribed dose. Check the amount of medication in the syringe to make sure it’s the correct dose.
  2. Check for air bubbles in the syringe. If you see any air bubbles, pull more medication into the syringe. They will go to the top, towards the needle. Slowly push the air bubbles and the extra medication back into the vial. Look at the syringe again to make sure that you have the right amount of medication.
  3. When you have the correct amount, pull the needle out of the vial. Place the cap back on the syringe without touching or bending the needle. If you touch or bend the needle, you will need to throw away the syringe and start at step 2. When you place the cap back on the syringe, make sure you don’t push the plunger by accident. This will push the medication into the cap and result in the wrong amount when it’s time to inject yourself.
  4. If you’re using Trimix, put the medication vial back into the refrigerator. If you’re using Bimix or Papaverine, you don’t need to keep your medication in the refrigerator.
Choosing an injection site

You must inject the medication into a specific area of your penis. This is so you don’t inject into a nerve or blood vessel.

Imagine that your penis is divided in 3 parts. You will give the injection in the middle third of your penis at the 10 o’clock (left side) or the 2 o’clock (right side) position (see Figure 3).

Figure 3. Choosing an injection site

To prevent trauma to your penile tissue, always change sides of your penis each time you inject the medication (right side, then left side). Keep a record each time so you don’t forget. Don’t inject into any vein you can see or feel because it could cause a large bruise on your penis. Don’t inject straight down on the top or the bottom of your penis.

Injecting the medication
  1. Grasp the head of your penis, not the skin. This will allow your penis to be more fully stretched. It’s easiest to inject if your penis is pulled straight out in front of you. If you aren’t circumcised, pull your foreskin back before grasping the head of your penis. This will prevent the needle from going between the skin and erectile tissue. For your injection to work, the medication needs to go into the erectile tissue.
  2. Locate the area to be injected (the middle third of your penis). Wipe it with an alcohol wipe. Let go of the head of your penis and pick up the syringe with 2 hands.
  3. Remove the cap covering the needle. Look at the syringe to make sure the dose is correct and you haven’t pushed any medication out by accident.
  4. Hold the syringe between your thumb, index and middle fingers like a pen or a dart. The needle should be facing the floor. Don’t place your index finger or thumb on the plunger.
  5. Once again, grasp the head of your penis and pull it straight out. Keep pulling on your penis from the time the needle goes into your penis until it comes out. Don’t twist your penis, since this could lead to injecting the wrong area.
  6. Touch the needle to your skin and quickly slide it into the shaft of your penis. Remember to avoid any veins. Make sure to insert the needle at a slight angle (either the 10 o’clock or 2 o’clock position, as shown in Figure 3).
  7. Move your finger so that your index finger or thumb can push in the plunger.
  8. Quickly push down on the plunger to inject the medication into the shaft of your penis. Be careful not to pull the syringe out as you’re injecting the medication.
  9. Once you have injected all of the medication, quickly pull the needle out of your penis. Pull it straight out. Don’t use a twisting or jerking motion, because this may cause bruising. Apply pressure at the injection site for 2 to 3 minutes with your thumb on the injection site and your index finger on the opposite side of your penis. If you’re taking a blood thinner or aspirin, hold the pressure for 5 minutes. This will help to decrease any bleeding or bruising.
  10. Place the syringe in the sharps container. You don’t need to recap it.
Erection Scale

It usually takes a few injections to find the right dose for an erection firm enough to have sex. It’s important that you follow the treatment plan that your APP gave you. Don’t adjust your own dosing. If you’re adjusting your own medication dosing, the office will no longer be able to prescribe your medication.

Please use the grading scale below to rate your level of hardness after injecting. 

Reporting your injections

Please make sure to include the information below in your injection reports.

For your first injection: inject ___________ units of ____________________________ while you’re at home.

Use the erection scale above and record your response below.

  • My erection was a _________ on a scale of 0 to 10.
  • My erection lasted _________ minutes/hours until it became a 5 on the erection scale.

Keep a log of your results so that we can find the ideal dosage for you.

Do not give yourself your next injection until you have reported the result of your last injection.

Important Points

  • Don’t take more medication than the dose prescribed.
  • Don’t change the dose without emailing
  • Don’t take more than 1 injection in 24 hours.
  • Don’t give yourself another injection if the medication doesn’t work. Speak with your
  • APP if you aren’t getting the effects you want.
  • You can inject up to 3 times a week as long as there are 24 hours between each injection.
  • If you’re currently receiving chemotherapy for cancer, ask your oncologist (cancer doctor) when you can safely inject.
  • Don’t take any other medication for ED without speaking to your APP. Do not inject within 72 hours (3 days) of taking tadalafil (Cialis) 10 mg or 20 mg.
  • It is OK to use if you’re using tadalafil (Cialis) 5 mg daily.
  • Tell Dr. Brandeis all of the medications you’re taking, especially if you’re taking one of the following:
    • Medication for high blood pressure
    • Medication for depression, or classified as an MAO inhibitor such as phenelzine (Nardil®)
    • A sleep aid, such as trazodone (Oleptro ER®)


Dr. Brandeis will order your supplies for you from a compounding pharmacy. Your supplies will include:

  • 1 vial (500 units) of ______________________ medication
  • 30 syringes (29 gauge, ½ inch)
  • 24 pseudoephedrine HCl (Sudafed®) 30 mg tablets

You will also need to buy alcohol pads from your local pharmacy.