SebringR, here's a short description I'm lifting from another website describing MUSE:
"MUSE stands for "medicated urethral system for erections." The medicine is a small pellet that is inserted inside the opening at the end of the penis (urethra). The applicator has a thin tube that contains the pellet of medicine. The tube is inserted into the urethra. By pressing a button on the applicator, you release the pellet. The medicine is absorbed through the membrane that lines the inside of the urethra."
My Urologist prescribed that I take a combination of Cialis (20mg) three times a week and one hour after I've taken the Cialis to take the MUSE - known also as alprostadil (250mcg).