Cialis is a prescription medication used to treat erectile dysfunction (ED) and the symptoms of benign prostatic hyperplasia (BPH) in men. Its active ingredient is tadalafil, which belongs to a class of drugs known as PDE5 inhibitors.
Cialis works by increasing blood flow to the penis during sexual stimulation, helping men achieve and maintain an erection. Unlike some other ED medications, Cialis is known for its long duration of action — it can remain effective for up to 36 hours, earning it the nickname "the weekend pill."