Cialis was also investigated in combination with finasteride, another BPH medication, in another trial. Other uses for this medicine This medication may be prescribed for other uses; ask your doctor or pharmacist for more information. Always talk to your doctor before incorporating any medication into your life, including those that are available over the counter. To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you. Continue to take tadalafil even if you feel well. It contains the ingredient alprostadil, a natural prostaglandin. The table below summarizes the typical dosages for tadalafil: Indications of Tadalafil:.Cialis (tadalafil) is a prescription medication for those with erectile dysfunction. Many providers sell Cialis online — learn about the safest and most discreet providers here. Cialis is a medication approved by the Food and Drug Administration (FDA) often used to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH) in those assigned male at birth. Interactions. 1. How it works. Cialis is a brand (trade) name for tadalafil which may be used to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH). Cialis (tadalafil) works by blocking the action of an enzyme known as cGMP-specific phosphodiesterase type-5 (PDE-5).