Trimix is injected into the side of the shaft of the penis (an intracavernosal injection) with a very short, very fine insulin syringe, using the exact site, volume, and frequency your prescriber sets. Most urology practices teach the technique in person and give the first dose in the office so they can watch the response before you inject at home. Everything below explains what the terms on your prescription and your vial label mean, not what dose you should use.
The preparation itself is compounded trimix injection, which combines alprostadil, papaverine, and phentolamine in one solution, prepared by Bayview Pharmacy to the strength written on the prescription. It is prescription-only and is not an FDA-approved product. Your prescriber decides whether it is appropriate for you and what dose you use.
What is trimix?
Trimix is a compounded injectable that contains three active ingredients in a single vial:
The three act locally on the blood vessels and smooth muscle inside the penis. Injectable therapy is one of several erectile dysfunction options described in the American Urological Association ED guideline, and providers often consider it when oral medications are not suitable or have not worked well enough. There is no mass-produced trimix product, which is why it comes from a compounding pharmacy: the pharmacy prepares the combination and concentration the prescriber orders.
Bimix, trimix, and quadmix: what is the difference?
The injectable combinations differ in how many active ingredients they contain. The table describes composition and form only. It is not a statement that any option is better, stronger, faster, or more effective, and it is not a recommendation.
| Preparation | Actives | Route |
|---|---|---|
| Alprostadil injection | Alprostadil only | Intracavernosal |
| Bimix | Papaverine, phentolamine | Intracavernosal |
| Trimix | Alprostadil, papaverine, phentolamine | Intracavernosal |
| Quadmix, atropine trimix | Trimix actives plus atropine | Intracavernosal |
| Triple-P urethral gel | Same three actives | Urethral (needle-free) |
Bimix contains no prostaglandin, all four injectables are solutions, and every one of these is compounded and not FDA-approved.
How to inject trimix: the steps a prescriber teaches
Injection technique is taught by the prescriber or a nurse in the office, usually with a demonstration and a supervised first dose. What follows is the general shape of that training so the instructions are familiar when you hear them. Follow your own prescriber's instructions wherever they differ from this outline.
Call your prescriber if you are not confident about any step, and call before you change anything about how or how much you inject. A Bayview pharmacist can answer questions about the prescription itself, but the pharmacy does not provide consultations and does not set doses.
What size needle for trimix injection?
Prescribers commonly have patients use an insulin syringe, where the needle is fine and short and the barrel is marked in units. For comparison, the Caverject (alprostadil) prescribing information calls for a 29 or 30 gauge, one-half inch needle for injection. Higher gauge means a thinner needle. The specific syringe, needle length, and gauge are part of your prescriber's instructions, and the syringe you are told to use also determines how the volume is measured out, which is the source of most of the confusion about "units."
Is 20 units of trimix a lot?
That question cannot be answered outside of your prescriber's office, and the honest answer is that "a lot" is defined by the individual, the concentration in the vial, and the response observed during titration. Two people holding vials labeled 20 units are not necessarily receiving the same amount of drug, because the concentration differs. The prescriber sets the starting dose, watches the response, and adjusts.
What can be explained is the arithmetic. On a standard U-100 insulin syringe, 100 units equals 1 mL, so 1 unit equals 0.01 mL. Twenty units on that syringe is 0.2 mL of whatever solution is in your vial. That is a volume, not a strength. The amount of each active ingredient you receive is that volume multiplied by the concentration on your label.
Terms you will see on the label
| Term | Meaning | Bayview vial |
|---|---|---|
| units | Insulin syringe marks | 100 units = 1 mL |
| mL | Solution volume | 2.5 mL multi-dose vial |
| alprostadil mcg/mL | Micrograms per mL | 2.5 to 100 mcg/mL |
| papaverine mg/mL | Milligrams per mL | 30 mg/mL, fixed |
| phentolamine mg/mL | Milligrams per mL | 1 to 6 mg/mL |
| beyond-use date | Last usable date | Printed on your label |
Units measure volume and not drug strength (1 unit is 0.01 mL), and the beyond-use date on your label governs whatever else you have read.
What is the maximum dose of trimix, and what is the strongest trimix?
Both are prescriber decisions, made for one person at a time, and neither has a single published answer that applies to everyone. A maximum dose is written on your prescription by the clinician who titrated you to it, along with a maximum frequency. Do not exceed either, and do not change your dose on your own.
"Strongest" usually means the highest concentration rather than anything about how well a preparation performs. Bayview compounds 27 validated trimix strengths, with alprostadil from 2.5 to 100 mcg/mL, papaverine at 30 mg/mL, and phentolamine from 1 to 6 mg/mL. A higher concentration is not a better preparation, and there is no correct strength to ask for. The prescriber selects the concentration and the volume together, which is why titration usually starts low and moves in small steps under supervision.
How long does trimix last?
Two different questions get asked with the same words. If you mean how long an individual dose acts, that is specific to the person, the concentration, and the volume, and it is a question for the prescriber who is titrating you. Onset and duration are exactly what they are watching during that in-office titration.
If you mean how long the vial keeps, the answer is on the label. Which brings up the question below.
How long does trimix last in the refrigerator?
Store the vial as directed on your label, which for trimix is generally refrigerated, protected from light, and away from heat and moisture. Keep it out of the reach of children.
The beyond-use date printed on your label is the one that governs. It is assigned for your specific preparation, and no number you find in a forum, on another pharmacy's page, or in an old prescription applies to the vial in your refrigerator. If the vial has passed its beyond-use date, if it has been left out, or if the solution looks cloudy or discolored, call the pharmacy rather than using it. Dispose of needles and syringes in an approved sharps container.
Priapism: the one thing to plan for before your first dose
A prolonged erection is a medical emergency. Your prescriber will tell you the time limit that applies to you; 4 hours is the threshold commonly cited in the urology literature and on the Urology Care Foundation's priapism page. An erection lasting beyond that point can cause permanent damage if it is not treated promptly, so go to the emergency room or seek immediate care rather than waiting to see whether it resolves.
Know before your first injection where you would go and who you would call. For urology practices that manage priapism in the office, Bayview compounds a phenylephrine priapism rescue preparation on a prescriber's order. That is a clinician-administered preparation, not something a patient keeps at home.
Other reported effects of penile injection therapy include pain or aching at the injection site, which can be associated with the alprostadil component, bruising or minor bleeding, dizziness or flushing, and, with long-term use, scarring or firm areas (fibrosis) in the penile tissue. Report new or worsening penile pain, curvature, or lumps to your provider promptly. Injection therapy is not appropriate for everyone, and extra caution applies with conditions that raise the risk of prolonged erection such as sickle cell disease, leukemia, or multiple myeloma.
How much does trimix cost?
At Bayview, compounded trimix injection starts at $100 for a 2.5 mL multi-dose vial. What you pay depends on the strength your prescriber orders and the quantity dispensed, since the higher-concentration validated strengths and the larger vial sizes are priced differently. Prices are cash prices and are subject to change, so call with your prescription in hand for a quote on your specific strength and quantity.
Compounded preparations are generally not billed through insurance, which is covered in more detail in do compounding pharmacies take insurance. A cash price is the whole price, with no deductible or prior authorization in the way.
What Bayview compounds for this
On a prescriber's order, Bayview prepares trimix injection in 2.5 mL multi-dose vials, compounded in our USP 797 sterile lab. Papaverine is held at 30 mg/mL while alprostadil (2.5 to 100 mcg/mL) and phentolamine (1 to 6 mg/mL) vary across 27 validated strengths, so a prescriber can titrate in small steps. The related injectables (bimix without the prostaglandin, quadmix and atropine trimix with a fourth active) and the needle-free Triple-P urethral gel are prepared the same way. The rest of the line is in our compounded medications catalog.
Talk to your prescriber
If injectable therapy is something you want to ask about, that conversation belongs with a urologist or your prescribing provider, who can decide whether it is appropriate, teach the injection technique, and set your dose. If they write for trimix, they can e-prescribe, fax, or phone the order to Bayview Pharmacy in Warwick, Rhode Island, and we can fill and ship it to the states where Bayview is licensed. Details are on our FAQ page, and a pharmacist is available for questions about your prescription.
Frequently asked questions
How should I store my ED injection medication?
Storage depends on the specific formulation and the instructions on your prescription label. Many sterile compounded ED injections are stored refrigerated or frozen to help maintain stability. Keep the medication protected from heat and light, do not use it beyond the labeled beyond-use date, and do not use it if it appears cloudy, discolored, contaminated, or otherwise unusual unless your pharmacist confirms it is acceptable.
What is priapism and what should I do if it happens?
Priapism is an erection that lasts too long and does not go away normally. An erection lasting 4 hours or longer is a medical emergency because it can cause permanent injury if not treated promptly. Follow your prescriber’s emergency instructions and seek urgent medical care if this occurs.
What side effects can occur?
Possible side effects include penile pain, bruising, bleeding at the injection site, temporary swelling, aching, dizziness, firmness lasting longer than desired, or development of scar tissue with repeated use. Seek urgent medical attention for an erection lasting 4 hours or longer, severe pain, significant swelling, or symptoms that concern you.
How often can I use ED injections?
Use only as directed by your prescriber. Many protocols limit use to a certain number of times per week with spacing between doses to reduce the risk of priapism, bruising, irritation, or tissue changes. Do not increase your dose or frequency unless your prescriber tells you to.
How quickly do ED injections work?
Many patients experience a response within several minutes, but timing can vary depending on the formulation, dose, injection technique, and individual response. Follow your prescriber’s instructions regarding when to use the medication and how long to wait before sexual activity.
How are ED injections used?
These medications are injected into the side of the penis using the dose and technique taught by your prescriber. The injection should not be given into a vein, the top of the penis, the underside of the penis, or through visible blood vessels. Always follow the specific instructions provided by your prescriber.
How do I know which ED injection is right for me?
Your prescriber determines the most appropriate formulation and starting dose. Factors may include prior ED treatment response, side effects, medical history, cardiovascular status, and whether you have used injectable therapy before. Bayview Pharmacy prepares the medication as prescribed but does not determine which formula is clinically appropriate for you.
What is the difference between Alprostadil, BiMix, TriMix, Atropine TriMix, and QuadMix?
The main difference is the combination of active ingredients. Alprostadil contains a single active medication. BiMix usually contains two medications. TriMix usually contains three. Atropine TriMix includes atropine in addition to a TriMix-style formula, and QuadMix generally contains four medications. Your prescriber chooses the formulation based on your medical history, response to treatment, and tolerance.
Why are ED injections compounded?
ED injections are often compounded because prescribers may need a specific combination, strength, or dose that is not available as a standard manufactured product. Compounding allows the medication to be prepared according to the prescriber’s instructions and adjusted to the patient’s individual response.
What are compounded erectile dysfunction injections?
Compounded erectile dysfunction injections are sterile prescription medications injected directly into the side of the penis to help produce an erection. Depending on the prescription, the injection may contain one medication, such as alprostadil, or a combination of medications, such as papaverine, phentolamine, alprostadil, and/or atropine.
What size needle for trimix injection?
Prescribers commonly have patients use an insulin syringe, where the needle is short and fine and the barrel is marked in units. For comparison, the Caverject (alprostadil) prescribing information calls for a 29 or 30 gauge, one-half inch needle for injection. Higher gauge means a thinner needle. The exact syringe, needle length, and gauge are part of your prescriber's instructions, and the syringe you are told to use also determines how your volume is measured out.
Is 20 units of trimix a lot?
That is a question for the prescriber who titrated your dose. What can be explained is the arithmetic: on a U-100 insulin syringe, 100 units equals 1 mL, so 20 units is 0.2 mL. That is a volume, not a strength. How much of each active ingredient it contains depends on the concentration printed on your vial label, which differs from one prescription to another.
What is the maximum dose of trimix?
There is no single maximum that applies to everyone. Your prescriber writes a maximum volume and a maximum frequency on your prescription after titrating you in the office, and those numbers are the ones that apply to you. Do not exceed either, and do not change your dose on your own. Call your prescriber if you think an adjustment is needed.
What is the strongest trimix?
"Strongest" usually means the highest concentration rather than anything about performance. Bayview compounds 27 validated trimix strengths, with alprostadil from 2.5 to 100 mcg/mL, papaverine at 30 mg/mL, and phentolamine from 1 to 6 mg/mL. A higher concentration is not a better preparation. The prescriber selects the concentration and the injected volume together for the individual patient.
How long does trimix last in the refrigerator?
Store the vial exactly as your label directs, which for trimix is generally refrigerated, protected from light, and away from heat and moisture. The beyond-use date printed on your label is the one that governs, and no number from a forum or an old prescription applies to your vial. If it is past that date, has been left out, or looks cloudy or discolored, call the pharmacy instead of using it.
How much does trimix cost?
At Bayview, compounded trimix injection starts at $100 for a 2.5 mL multi-dose vial. What you pay depends on the strength your prescriber orders and the quantity dispensed, since higher-concentration validated strengths and larger vial sizes are priced differently. Prices are cash prices and subject to change. Compounded preparations are generally not billed through insurance, so call with your prescription for a quote.
What is trimix made of?
Trimix is a compounded injectable containing three actives in one solution: alprostadil (a prostaglandin E1 vasodilator), papaverine (a smooth-muscle relaxant), and phentolamine (a non-selective alpha-adrenergic blocker). There is no mass-produced trimix product, so the combination and concentration are compounded to the prescription. It is prescription-only and is not FDA-approved.
Do I inject trimix the first time at home?
Typically no. Urology practices generally teach the technique in person and give the first dose under clinical supervision so they can watch the response before you inject on your own. Ask your prescriber how they handle the first dose, what site to use, how long to hold pressure, and what time limit applies to you for seeking emergency care for a prolonged erection.
What Bayview compounds for this
Important: Compounded medications are prepared to a prescriber's order for an individual patient. They are not FDA-approved, and the FDA has not evaluated them for safety, effectiveness, or manufacturing quality. This article is educational and is not a substitute for advice from your prescriber or pharmacist.
This preparation contains a controlled substance. Controlled-substance prescriptions carry refill limits, must be e-prescribed, and can only be shipped to states where Bayview holds the required licensure.
Uses discussed here may be off-label, meaning they are not part of any FDA-approved labeling. Off-label use is a decision for you and your prescriber, based on the available evidence.
Veterinary preparations are compounded to a veterinarian's order for a specific animal and are not FDA-approved animal drugs. Never give a compounded human medication to an animal without veterinary direction.
Compounded prescriptions are paid for directly rather than billed through insurance. Most are HSA/FSA-eligible, and many patients submit the receipt to their plan for possible reimbursement. Pricing depends on the strength, dose form and quantity your prescriber orders. Read more about cost and insurance.
Compounded trimix injection starts at $100 for a 2.5 mL multi-dose vial at Bayview, and the final price depends on the strength your prescriber orders and the quantity dispensed, since higher-concentration validated strengths and larger vial sizes are priced differently. These are cash prices and are subject to change. Compounded preparations are generally not billed through insurance because they are prepared to an individual prescription rather than carried as a manufactured product, so there is no deductible or prior authorization involved. Call with your prescription in hand for a quote on your specific strength and quantity.
Bayview Pharmacy is a compounding pharmacy in Warwick, Rhode Island, licensed to fill and ship compounded prescriptions for patients in Rhode Island, Massachusetts, Connecticut, New Jersey, New Hampshire, Florida, Maine and Pennsylvania. Prescriptions for New York patients are filled on a limited basis, and controlled substances are not shipped to New York addresses. See every state we ship to.
