Tadalafil belongs to a group of medicines, known as phosphodiesterase-5 (PDE-5) inhibitors, which are used to treat erectile dysfunction or pulmonary arterial hypertension. 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. Tadalafil relaxes muscles of the blood vessels and increases blood flow to particular areas of the body. Tadalafil under the name of Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). Tadalafil is FDA -approved for males as a therapy to treat and prevent symptoms of benign prostatic hyperplasia, such as urinary urgency, hesitancy, weak stream, dribbling, and incontinence. Brand names: Cialis, Adcirca. Tadalafil comes only as a tablet you take by mouth. Tadalafil is used to treat the symptoms of benign prostatic hyperplasia (BPH) and erectile dysfunction (ED). Tadalafil is a generic drug prescribed for erectile dysfunction and other conditions. Learn about the drug’s dosages, form, strengths, and more. Medscape - Erectile dysfunction, pulmonary arterial hypertension-specific dosing for Adcirca, Cialis (tadalafil), frequency-based adverse effects, comprehensive interactions, contraindications. Tadalafil is used to treat men who have erectile dysfunction (also called sexual impotence). Tadalafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. Tadalafil tablets treat erectile dysfunction by increasing blood flow to your penis. This helps you maintain an erection. It can also treat benign prostatic hyperplasia. What is tadalafil, and what is it used for? Tadalafil is an oral drug that is used for treating impotence, or erectile dysfunction (the inability to attain or maintain a penile erection), and benign prostatic hyperplasia (BPH).