Who this guide is for
This guide is for men who have already been evaluated for erectile dysfunction, been recommended Trimix, and had their first injection supervised in a clinic. It is a refresher on safe technique at home, not a substitute for hands-on training. If you have not yet had an in-office test dose, stop here and book one.
Trimix is a compounded blend of three medicines, papaverine, phentolamine and alprostadil, injected into the side of the penis to produce an erection within minutes. Because it is compounded, the FDA notes that compounded drugs are not FDA-approved, which is one reason your dose and technique should come from the clinician managing your treatment. Our page on Trimix injections explains who it suits.
Before your first home injection
The American Urological Association recommends an in-office injection test for men considering penile injection therapy. That visit shows how you respond to a starting dose and gives you a chance to inject under supervision. MedlinePlus describes the same approach for alprostadil: the first dose is given in the office to find the right dose for you.
Before you inject at home, make sure you have:
- A written dose, in the units marked on your syringe, from your provider
- A written plan for an erection that lasts too long, including who to call
- Your medicine stored as instructed; our page on how to store Trimix covers temperature and shelf life
- Alcohol swabs, the syringes supplied, gauze and a sharps container
- A well-lit, private place to sit
- A clock or phone to note the time of the injection
If you take a blood thinner, tell your provider before your first home dose. Our page on Trimix and blood thinners explains the extra precautions.
The injection, step by step
Where to inject: the 2 and 10 o’clock zones
Picture the penis as a clock face, looking down at it from above, with 12 o’clock on the top. The top of the shaft carries the main nerves and blood vessels. The underside, around 6 o’clock, holds the urethra, the tube that carries urine. The safe zones sit on either side, at roughly 2 o’clock and 10 o’clock.
The FDA-approved label for CAVERJECT, an alprostadil injection, describes the same area in medical terms: the dorso-lateral side of the shaft, in the third nearest the body. It also says to avoid visible veins and to alternate the side of the penis you inject each time. Your provider will show you the exact area on your own body.
The steps
- Wash your hands and lay out your supplies on a clean surface.
- Check the medicine. Do not use it if it looks cloudy or has particles, or if it has been stored incorrectly.
- Draw up exactly the dose your provider set, using the technique you were taught. Remove air bubbles.
- Get into position. Sit comfortably. If uncircumcised, pull back the foreskin. Hold the head of the penis and gently stretch the shaft along your thigh so the side is flat and visible.
- Choose your side. Use the opposite side from last time. Pick a spot at about 2 or 10 o’clock, in the base third of the shaft, away from any vein you can see.
- Clean the spot with an alcohol swab and let it dry.
- Insert the needle straight in, at a right angle to the shaft, in one smooth motion. MedlinePlus notes it should be inserted perpendicular to the long axis of the penis.
- Inject slowly and steadily, then withdraw.
- Apply pressure. The CAVERJECT label says to compress the site with an alcohol swab or gauze for 5 minutes. This reduces bruising.
- Dispose of the syringe straight into your sharps container. Our guide to needle disposal in Los Angeles County lists drop-off options.
- Note the time, then allow arousal and foreplay. The erection usually develops within minutes.
Why dose changes happen only with your provider
It is tempting to add a little more if one injection did not give the result you wanted. Do not. MedlinePlus advises patients not to change their alprostadil dose without talking to their doctor, and the same principle applies to Trimix. Small changes can make the difference between a firm erection and one that will not go down.
A weak response can come from many things other than dose: nerves, alcohol, a missed vessel, poor technique or injecting too far from the base. Your provider looks at those first. If a change is needed, the provider adjusts it and tells you the new dose in writing.
Keep a simple log after each use: date, dose, side, time to erection, how firm and how long it lasted. That log is what your provider needs to make a safe adjustment. For frequency, follow your provider’s instructions; MedlinePlus notes that alprostadil injection should not be used more than three times a week, with at least 24 hours between uses, and our page on how often to use Trimix covers the general guidance.
The four-hour rule
An erection that will not go down is the most important risk of Trimix. The AUA/SMSNA priapism guideline treats prolonged ischemic priapism as an emergency, because blood trapped in the penis loses oxygen and the tissue can be permanently damaged. The longer it lasts, the higher the risk of lasting erectile problems.
Follow this plan every time:
- Note the time of each injection.
- If the erection lasts longer than your provider told you to expect, follow your written plan and call the clinic or the after-hours number you were given.
- If it reaches four hours, go to an emergency room or call 911. Do not wait to see if it settles, and do not try to drive yourself if you are in severe pain.
- Tell the ER that you injected Trimix, and when.
Our page on an erection lasting more than four hours explains what happens in the ER, and our page on phenylephrine for priapism covers one of the treatments used.
What to watch for, and when to call
Some side effects are minor; others need a call.
Expected and usually minor:
- a small bruise or a drop of blood at the site
- a mild ache in the shaft for a short time after the injection
Call the clinic if you notice:
- a new lump or hard area in the shaft
- the penis starting to curve or bend when erect
- bruising that keeps getting larger
- pain during the injection that is sharp rather than brief
MedlinePlus lists unusual curving of the erect penis and nodules or hard areas on the penis among the serious side effects of alprostadil injection. These can be signs of scarring, which our page on Trimix and scarring discusses.
Call 911 or go to the ER for:
- an erection lasting four hours or more
- chest pain, fainting or severe dizziness after an injection
- swelling of the face, lips or throat, or trouble breathing
How Ultimate Male supports Trimix users
At our San Gabriel and Downey clinics, Trimix starts with an evaluation: a review of your history and medicines, labs where needed and a consultation with a PA-C or MD. Whether injections suit you is decided at that visit, not assumed. If they do, the provider walks you through technique and explains the plan for a prolonged erection before you inject at home. Ask on the free 10-minute call how the first in-office injection visit is scheduled.
Follow-up is where most improvements happen. Bring your log, and any changes to dose are made by the provider, in writing. Compounded Trimix and Quadmix come from licensed U.S. compounding pharmacies. To see every option, from pills to injections, visit our page on ED medications.
