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 Common brands: Cialis, Cialis Together, Adcirca Tadalafil is a medicine mainly used to treat erection problems. You can buy it from a pharmacy after speaking with a pharmacist, but it's mostly available with a prescription. 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). If you take tadalafil for pulmonary arterial hypertension, do not take Cialis® or other PDE5 inhibitors, including sildenafil (Revatio® or Viagra®) or vardenafil (Levitra®). Persons surnamed Cialis objected to Eli Lilly and Company's so naming the drug, but the company has maintained that the drug's trade name is unrelated to the surname. Tadalafil is also available under the brand names Cialis and Adcirca. Typically, your doctor will start by prescribing a low dosage, then adjust it over time to reach the right amount for you. 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 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 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.