Penile Injection Therapy (Trimix)
The most reliable ED treatment available — with a success rate exceeding 90%. Trimix delivers medication directly to the erectile tissue for men who don't respond to oral medications.
What Is Penile Injection Therapy?
Penile injection therapy, also known as intracavernosal injection (ICI) therapy, is the direct injection of vasodilating medication into the side of the penis to produce an erection. The most commonly used formulation is Trimix — a compounded medication containing three active ingredients: papaverine, phentolamine, and prostaglandin E1 (alprostadil).
Unlike oral PDE5 inhibitors (sildenafil and tadalafil) that work systemically and require sexual arousal, Trimix works by directly relaxing the smooth muscle and dilating the blood vessels within the erectile tissue itself. This means it produces a reliable erection within 5 to 15 minutes — and it does not require sexual arousal to work. The success rate exceeds 90%, making it the most effective non-surgical ED treatment available.
At Rewind Anti-Aging of Miami, we provide thorough in-office training, careful dose titration, and ongoing monitoring to ensure safe, effective results. Every aspect of the treatment — from consultation to dispensing — is handled with complete discretion and confidentiality.
How Trimix Works
Trimix uses three medications with complementary mechanisms, creating a synergistic effect that is more reliable than any single agent alone.
Papaverine
A non-specific smooth muscle relaxant that directly relaxes the smooth muscle of the corpora cavernosa and penile blood vessels, allowing increased blood flow.
Phentolamine
An alpha-adrenergic blocker that prevents the sympathetic nervous system from constricting penile blood vessels, further enhancing blood flow and reducing the "fight or flight" response that can inhibit erections.
Prostaglandin E1
Also known as alprostadil, this vasodilator directly relaxes vascular smooth muscle and also stimulates the production of cGMP — the same molecule that PDE5 inhibitors work to preserve.
Why Three Ingredients?
The triple-agent approach is what makes Trimix so effective. Each ingredient works through a different pathway — smooth muscle relaxation (papaverine), sympathetic blockade (phentolamine), and direct vasodilation with cGMP stimulation (prostaglandin E1). By targeting three mechanisms simultaneously, Trimix achieves reliable results even in men with severe ED who have failed oral medications. The concentrations of each ingredient can be customized to each patient's response, allowing fine-tuned dosing that maximizes efficacy while minimizing side effects.
Who Is Penile Injection Therapy For?
Men Who Don't Respond to Oral Medications
Approximately 30% of men with ED do not respond adequately to PDE5 inhibitors like sildenafil and tadalafil. For these men, penile injection therapy provides a direct, mechanical alternative with a success rate exceeding 90%. The medication is delivered directly where it is needed, bypassing the oral absorption and systemic circulation that limit pill-based treatments.
Learn about oral ED medications →Post-Prostatectomy Patients
Prostate surgery (radical prostatectomy) can damage the cavernous nerves responsible for erections. Penile injection therapy bypasses the nerve pathway entirely, delivering medication directly to the erectile tissue. It is one of the most effective treatments for post-surgical ED and is often used as part of a penile rehabilitation program to preserve erectile tissue health.
Men with Contraindications to PDE5 Inhibitors
Men who take nitrate medications for heart conditions cannot use sildenafil or tadalafil due to the risk of dangerous blood pressure drops. Penile injection therapy provides an effective ED treatment that does not interact with nitrates or most other cardiac medications, making it a safe alternative for men with complex cardiovascular histories.
What to Expect
From your first consultation to confident self-administration — every step is handled with medical precision and complete discretion.
Consultation & Evaluation
We review your ED history, prior treatments, current medications, and cardiovascular health. We discuss expectations and answer all questions.
In-Office Dose Titration
Your first injection is administered by our medical staff in the office. We start with a low dose and carefully increase until we find the minimum dose that produces a satisfactory erection.
Injection Training
We teach you the self-injection technique — proper needle angle, injection site rotation, aspiration, and injection speed. Most men are comfortable after 1-2 practice sessions.
Prescription & Dispensing
We prescribe your customized Trimix formulation, prepared by a licensed compounding pharmacy. The medication requires refrigeration and has specific storage instructions.
Ongoing Monitoring
Regular follow-ups to assess efficacy, check for fibrosis, adjust dosing, and ensure safe, consistent results over time.
Side Effects of Penile Injection Therapy
Understanding the risks is essential. Proper dose titration and injection technique minimize most side effects.
Injection Site Discomfort
Mild stinging or aching at the injection site, typically lasting only a few minutes. Using proper injection technique and rotating injection sites minimizes this.
Penile Bruising
Small bruises may occur at injection sites, especially early on. These are cosmetic, painless, and resolve within a few days. Proper technique reduces occurrence.
Prolonged Erection
An erection lasting longer than expected (1-2 hours) can occur, particularly during dose titration. We provide specific instructions for at-home management.
Priapism (Rare)
An erection lasting more than 4 hours is a medical emergency. Proper dose titration makes this rare (1-3%). We educate every patient on warning signs and emergency protocols.
Penile Fibrosis
With long-term, frequent use, scar tissue can develop at injection sites. Rotating injection sites and limiting frequency (no more than 3 times per week) reduces this risk.
Priapism Warning: An erection lasting more than 4 hours is a medical emergency. If this occurs, go to the nearest emergency room immediately. Proper dose titration — which we perform carefully in our office — makes priapism rare, but every patient must understand the signs and know when to seek help. We provide written emergency instructions with every prescription.
Related Treatments
ED Medications
Custom-compounded sildenafil and tadalafil troches with oxytocin, testosterone, and sermorelin for men who respond to oral PDE5 inhibitors.
Learn more →Sildenafil (Viagra) Treatment
Custom-compounded sildenafil in sublingual troches for faster onset — a first-line option before considering injectable therapy.
Learn more →PT-141 Therapy
Bremelanotide peptide that targets sexual desire at the neurological level — addresses the desire component that injection therapy does not.
Learn more →Learn More About ED Treatment
Cialis vs. Viagra: Which Is Right for You?
Understanding oral ED medications and when injectable therapy may be the better option.
Testosterone and Libido: The Connection
How testosterone levels affect sexual function and complement ED treatment strategies.
Signs of Low Testosterone in Men
How hormonal decline affects erectile function and sexual health beyond just blood flow.
What Is Trimix? How Penile Injection Therapy Works
Detailed guide to Trimix composition, self-injection, and what to expect.
Frequently Asked Questions
What is Trimix and how does it work?
Trimix is a compounded injectable medication containing three active ingredients: papaverine (a smooth muscle relaxant), phentolamine (an alpha-adrenergic blocker), and prostaglandin E1 (alprostadil, a vasodilator). Each ingredient works through a different mechanism to relax smooth muscle and dilate blood vessels in the corpora cavernosa (erectile chambers). The triple mechanism produces a reliable, predictable erection within 5 to 15 minutes of injection, regardless of whether sexual arousal is present.
Does penile injection therapy hurt?
Most patients are surprised at how minimal the discomfort is. The injection uses a very fine needle (30-gauge, similar to an insulin needle) and is administered into the side of the penis, which has fewer nerve endings than other areas. Most men describe the sensation as a slight pinch or mild sting that lasts one to two seconds. Any anxiety typically diminishes significantly after the first few self-administered injections. We train you thoroughly in our office before you ever inject at home.
What is priapism and how do you prevent it?
Priapism is a prolonged erection lasting more than 4 hours that does not resolve on its own. It is a medical emergency that requires prompt treatment to prevent tissue damage. With proper dosing, priapism is rare — occurring in approximately 1-3% of patients. We prevent it by starting with a very low dose and titrating upward gradually in our office, finding the minimum effective dose for each patient. We also provide clear instructions on what to do if an erection lasts longer than expected, including when to seek emergency care.
How long does the erection from Trimix last?
A typical Trimix-induced erection lasts 30 minutes to 1 hour, though this varies with dosing. The erection will typically resolve on its own after sexual activity and climax. If an erection persists beyond 2 hours, we provide specific instructions for at-home management. If it persists beyond 4 hours, it is important to seek immediate medical attention. Proper dose titration — which we perform carefully for each patient — minimizes the risk of prolonged erections.
Who is a candidate for penile injection therapy?
Penile injection therapy is primarily prescribed for men who have not responded adequately to oral PDE5 inhibitors (sildenafil, tadalafil), who cannot take PDE5 inhibitors due to contraindications (such as nitrate medications), or who have specific conditions like post-prostatectomy ED, severe diabetes-related ED, or Peyronie's disease. It is also used by men who prefer the reliability and predictability of injectable therapy. A medical evaluation is required to determine candidacy.
Is penile injection therapy confidential?
Absolutely. Sexual health is one of the most private areas of medicine, and we treat it accordingly. Your records are protected by HIPAA, consultations are conducted in private examination rooms, and the medication is dispensed discreetly. The injection supplies are small and portable — a vial and syringes that fit in a toiletry bag. No one would know what they are by looking at them.
When Pills Are Not Enough
Penile injection therapy provides reliable results for men who have not responded to oral medications. Every consultation is confidential, and every treatment plan is customized to your needs.
References
- Lue TF. Erectile dysfunction. N Engl J Med. 2000;342(24):1802-1813. Intracavernous injection therapy efficacy data exceeding 90% response rate.
- American Urological Association. Guidelines on the management of erectile dysfunction: diagnosis and treatment recommendations. AUA, 2018.
- Caverject (alprostadil for injection) prescribing information. Pfizer Inc. U.S. Food and Drug Administration.
- Mulhall JP, Jahoda AE, Graydon RJ, et al. The reliability of intracavernosal injection therapy and the likelihood of achieving optimal erections. J Urol. 2001;165(2):437-441.
⚕ Medical Disclaimer
The information on this page is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. All treatments at Rewind Anti-Aging of Miami are performed under the supervision of licensed medical professionals. Individual results may vary. Consult your physician before beginning any new treatment protocol.
Meet our clinical team →Areas We Serve in Miami & South Florida
Our Wynwood clinic at 24 NW 29th Street serves patients across the Miami metro in person and the entire state of Florida via telehealth.