What is the drug that causes the effect in ED drug muse (alprostadil)?

Alprostadil. Go to www.Muserx.Com for more information on alprostadil. By the way, the same medication, alprostadil, can also be injected into the penis for even better/stronger effect as caverject. Find out more information at www.Caverject.Com. There are also compounded versions of these drugs at specialty compounding pharmacies & clinics.