Cialis (Tadalafil) is a medicine used to treat erectile dysfunction in men. Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection. When a man is sexually stimulated, his body's normal response is to increase blood flow to his penis. This results in an erection. Cialis helps increase blood flow to the penis and may help men with erectile dysfunction get and keep an erection satisfactory for sexual activity. Once a man has completed sexual activity, blood flow to his penis decreases, and his erection goes away.
