Cialis (tadalafil) is a prescription tablet used for erectile dysfunction and benign prostate hyperplasia. Learn about alternatives, dosage, side effects, and more. Cialis is a popular ED medication. Find out everything you need to know about this doctor-prescribed medication including usage, effectiveness, safety considerations, and where to buy online. Find patient medical information for Tadalafil (Cialis, Adcirca, and others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Brand-name and generic Cialis (tadalafil) is an effective treatment for erectile dysfunction (ED) and an enlarged prostate. You can take Cialis for ED as needed before sex or on a daily basis. If you take tadalafil for pulmonary arterial hypertension, do not take Cialis® or other PDE5 inhibitors, including sildenafil (Revatio® or Viagra®) or vardenafil (Levitra®). Cialis relaxes muscles of the blood vessels and increases blood flow to particular areas of the body. Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). Cialis (tadalafil) is a prescription tablet used for erectile dysfunction and benign prostatic hyperplasia. Learn about dosage, side effects, and more. Cialis (tadalafil) is a prescription medication for erectile dysfunction (ED). It usually starts working within 30 minutes but can take up to 2 hours to fully set in. Be sure to follow your recommended Cialis dosage, whether you’re taking it every day or as needed. Tadalafil under the name of Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). Another brand of tadalafil is Adcirca, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women. Cialis (tadalafil) is used primarily to treat erectile dysfunction and symptoms of benign prostatic hyperplasia. Dosage varies based on treatment goals, ranging from daily low-dose to higher doses taken as needed.