B No evidence of risk in humans Based on FDA pregnancy categories Do not start or stop taking tadalafil during pregnancy without your doctor’s advice. If you miss a dose of Adcirca or Alyq, take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not split the dose. Since Cialis is used as needed, you are not likely to miss a dose. If you are taking tadalafil to treat erectile dysfunction, follow your doctor’s directions and the guidelines in this paragraph. Do not take a double dose or more than one dose per day to make up for a missed one. Call your doctor for medical advice about side effects.Tadalafil (Cialis) is used to treat erectile dysfunction (ED, impotence; inability to get or keep an erection), and the symptoms of benign prostatic hyperplasia (BPH; an enlarged . Find everything you need to know about Cialis (Tadalafil), including what it is used for, warnings, reviews, side effects, and interactions. Learn more about Cialis (Tadalafil) at . Cialis (tadalafil) increase increases blood flow to a certain area of the body and is used to treat erectile dysfunction (impotence). Includes Cialis side effects, interactions and .