Cialis, also known as tadalafil, is a long-acting drug used to improve male sexual function, mainly for the treatment of erectile dysfunction in men, and is the first-line drug recommended by many national medication guidelines for improving erectile dysfunction. The main action of Cialis is to improve erectile function through the inhibition of enzymes that relax the smooth muscles of the penile arteries and cavernous body of the penis, causing an increase in blood flow to the penis. The effect of Xanax, which is a phosphodiesterase 5 inhibitor, is relatively strong and is a long-acting drug, and patients are generally advised to take this drug 30 minutes before sex. In conclusion, Cialis is the first-line recommended drug for improving impotence symptoms.