Injection Therapy: Tri-Mix, Caverject, Alprostadiol, Papaverine, Phentolamine: During this process, the patient uses a small needle to inject a powerful muscle relaxant into the base of the penis. The relaxation of the muscle tissue allows blood to flow into the erectile tissues in the penis, which can then create an erection.

Potential Side Effects: Pain, bruising and tenderness, scarring, bleeding, abnormal liver enzymes, and prolonged erection (priapism).