Viridal 40 Duo is a prescription medication primarily used in the treatment of erectile dysfunction (ED) in men. It contains the active ingredient alprostadil, which belongs to a class of drugs known as prostaglandin E1 (PGE1) analogs. Alprostadil works by relaxing blood vessels and muscles in the penis, which increases blood flow and helps to achieve and maintain an erection suitable for sexual activity. Viridal 40 Duo is administered through an injection directly into the penis, offering an alternative for those who may not respond to oral ED medications. It is important for patients to receive proper instruction from healthcare professionals on how to use this medication safely and effectively.