Follow your doctor’s directions carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take all of the tablets for your daily dose at one time each day; do not divide the tablets to take as separate doses. One of the first Cialis ads aired at the Super Bowl. Tadalafil is sometimes taken as needed, usually at least 30 minutes before sexual activity and not more often than once every 24 hours. If you have certain health conditions or are taking certain medications, your doctor may tell you to take tadalafil less often or may prescribe a lower dose to be taken once a day.Tadalafil is a medicine used to treat erectile dysfunction (ED, also called impotence) and problems with urination caused by an enlarged prostate (benign prostatic hypertrophy or BPH). It is sometimes known by its generic name tadalafil, and sometimes known by its trade name, Cialis. There are also other brands of this medicine available. Tadalafil is the generic version of Cialis and is typically lower in cost. Cialis: A prescription of 30 Cialis pills costs $ Tadalafil: 30 tadalafil pills are available for $ Prices for the generic, known as tadalafil, are more than 50% less than those of brand-name Cialis. As more men are able to afford tadalafil and treat their ED, it’s .