Like sildenafil (the active ingredient in Viagra), avanafil (sold as Stendra) and other ED medications, tadalafil is available in several dosages, but unlike the others, it can also be prescribed. 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 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 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 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 a popular medication prescribed for erectile dysfunction (ED) and symptoms of benign prostatic hyperplasia (BPH). Understanding the correct dosage and timing is crucial for safe and effective treatment. 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 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. Tadalafil (Eqv-Cialis) is used in adult men to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). Tadalafil (Eqv-Cialis) can also be used in men and women to treat pulmonary arterial hypertension (PAH) and improve exercise capacity. Tadalafil is a generic drug prescribed for erectile dysfunction and other conditions. Learn about the drug’s dosages, form, strengths, and more.