Trimix Dosage Chart 2026 — Intracavernosal Injection Reference

Medical Disclaimer

This website is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting, changing, or stopping any medication or supplement. Dosage information reflects published FDA-approved labeling or publicly available clinical trial data — individual treatment decisions must be made by a licensed physician.

About Trimix (alprostadil + papaverine + phentolamine)

Trimix is a compounded intracavernosal injection used for erectile dysfunction. It contains three vasodilators: alprostadil (PGE1), papaverine, and phentolamine. Doses are highly individualized and must be titrated by a physician in office. This page is for informational reference only.

Indication

Erectile dysfunction — intracavernosal injection therapy. Physician titration required.

Research / Trial Dosing Reference

Dosing data from published clinical trials. Not an approved prescription protocol.

Week / Phase	Dose	At 2.5 mg/mL	At 5 mg/mL	Notes
Starting test dose (clinic)	5–10 mcg alprostadil equivalent	5 units (varies by pharmacy)	—	First dose MUST be given in physician office. Dose varies significantly by Trimix formulation strength.
Low maintenance dose	0.1 mL	10 units (formulation-specific)	—	In-office titrated starting home dose. Volume prescribed — not mg — due to variable formulations.
Mid maintenance dose	0.2–0.3 mL	20 units (formulation-specific)	—	Common effective home dose range after titration.

Units shown assume a standard U-100 insulin syringe (100 units = 1 mL). Always confirm your vial concentration with your pharmacy.

Dose Calculator

Enter your prescribed dose and vial concentration to calculate how many units to draw.

mg ↔ Units Dose Calculator

Convert between milligrams and insulin-syringe units for compounded GLP-1 medications. Uses a standard U-100 syringe (100 units = 1 mL).

Medication

Vial Concentration (mg/mL)

Dose (mg)

Units (U-100 syringe)100 units

Volume1.000 mL

2.5 mg at 2.5 mg/mL → 1.000 mL → 100 units on a U-100 (100-unit / 1 mL) insulin syringe

Always verify calculations with your prescribing provider or pharmacist before administering any medication. This calculator is for reference only.

Injection Sites

Intracavernosal (penile)

Injection into the corpus cavernosum of the penis. Must be taught by a healthcare provider.

First injection MUST be performed or supervised by a physician
Alternate sides with each injection
Apply pressure for 5 minutes after injection
Never inject into the urethra or glans
Seek emergency care immediately for erection lasting >4 hours (priapism)

Storage Instructions

Refrigerate compounded Trimix at 36°F–46°F
Protect from light
Typical shelf life: 3–6 months refrigerated (pharmacy-specific)
Do not freeze
Discard cloudy or discolored solution

Common Side Effects

Contact your healthcare provider if side effects are severe or persistent.

Penile pain (common, usually mild)
Priapism (prolonged erection >4 hours — EMERGENCY, requires immediate medical care)
Bruising at injection site
Scarring with repeated injections (rare)
Hypotension (rare)

Frequently Asked Questions

What are the components of Trimix?

Standard Trimix contains alprostadil (a prostaglandin E1 vasodilator), papaverine (a phosphodiesterase inhibitor), and phentolamine (an alpha-blocker). Different formulations vary in the ratio and concentration of these components, which is why doses are measured in volume (mL) rather than mg.

What is priapism and what should I do if it happens?

Priapism is a prolonged erection lasting more than 4 hours. It is a medical emergency — go to an emergency room immediately. Untreated priapism can cause permanent erectile dysfunction due to tissue damage.

How is Trimix different from Bimix?

Bimix contains only papaverine and phentolamine (no alprostadil). Trimix adds alprostadil, making it generally more potent. Trimix is more commonly prescribed for patients who do not respond adequately to Bimix.