Trimix is used to treat erectile dysfunction in men and consists of three medications from complementary drug classes that work together for enhanced effectiveness. This sterile injectable solution contains Papaverine, Phentolamine and Alprostadil. Papaverine is a vasodilator that promotes erections by widening blood vessels and increasing blood flow to the penis. The second component, Phentolamine—an alpha-adrenoceptor antagonist—supports erection by relaxing and expanding the blood vessels in the penis and boosting cardiac output. Noradrenaline normally maintains penile smooth muscle contraction by keeping the corpora cavernosa in a tightened state, and Phentolamine helps counteract this effect to facilitate an erection. The third component, Alprostadil, is a prostaglandin analog, a vasodilator frequently prescribed by healthcare professionals to treat erectile dysfunction (ED or impotence). It works by relaxing and expanding the walls of the blood vessels (arteries), promoting increased blood flow. Alprostadil replicates a naturally occurring substance in the body that helps maintain open blood vessels. Triimix is administered directly into the shaft of the penis using a very fine needle. It is effective for 1 to 2 hours.

Avoid using this medication if you have any of the following: an allergy or sensitivity to any of its ingredients; medical conditions that increase the risk of priapism (a painful erection lasting more than 4 hours), such as sickle cell anemia, multiple myeloma, or leukemia; anatomical abnormalities of the penis or the presence of a penile implant; or if your doctor has advised against sexual activity for health reasons.

Potential side effects include penile pain, bleeding at injection site, penile curvature, scar tissue in the penis ,erections lasting longer than 4 hours, bruising at injection site and blood pooling (hematoma) at or near the injection site.