Your doctor will help you decide the best time for you to take tadalafil before sexual activity. How long does Cialis last? Consult your physician about which is right for you. Talk to your doctor about which dosing schedule is right for you. ED occurs more frequently in older men. Other uses for this medicine This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.What is Cialis? 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). 5 mg, 10 mg, 20 mg: 50 mg, mg, mg: What’s the typical dosage? 50 mg: 10 mg as needed or mg daily: Daily Generic Cialis (tadalafil) Generic Cialis (tadalafil) Roman: $90 per dose. Cialis is available in a generic version. Cialis form and strengths ( mg, 5 mg, 10 mg, 20 mg) Cialis comes as oral tablets that are available in four strengths: milligrams (mg), 5 mg.