Cialis is the trade name for a drug called Tadalafil.
Cialis can help men with erectile dysfunction (male impotence) by enhancing the erectile response when a man is sexually stimulated.
Tadalafil, sold under the brand name Cialis among others, is a medication used to treat erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension. It is taken by mouth. Onset is typically within half an hour and the duration is up to 36 hours.