As long as you keep taking your daily tablet, Cialis Daily will keep working. Tadalafil may cause side effects. John’s wort. You may attempt sexual activity at any time between doses. Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. · Cialis (tadalafil) is prescribed to treat erectile dysfunction and symptoms of benign prostatic hyperplasia. It comes as a tablet that’s taken as needed or once per . Cialis comes as oral tablets that are available in four strengths: milligrams (mg), 5 mg, 10 mg, and 20 mg. Recommended dosage for Cialis Typically, . Cialis is a medication approved by the Food and Drug Administration (FDA) often used to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH) in .