Learn about tadalafil (Cialis) usage and dosing. Read the latest news and reviews about the drug as well as potential side effects and popular alternatives. 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). If you take Cialis as needed, it usually starts working within 30 minutes but can take up to 2 hours to fully set in. 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). Cialis (Tadalafil) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. 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 is a long-acting PDE5 inhibitor for erectile dysfunction, known for lasting up to 36 hours. It can be taken as needed or as a low daily dose, and it also treats benign prostatic hyperplasia. Like all ED pills, it needs sexual stimulation and must never be combined with nitrates. Tadalafil is prescription-only. Cialis (tadalafil) is a phosphodiesterase-5 (PDE5) inhibitor approved by the FDA to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH). You can take Cialis daily in low doses. What is Cialis used for? Cialis is a versatile drug with a few different applications. Aside from erectile dysfunction, tadalafil can effectively treat benign prostatic hyperplasia (BPH).