Tadalis tablets 20mg (generic Cialis) are used to treat erectile dysfunction (impotence) in men, which is inability to achieve or maintain a hard erect suitable for sexual activity, due to insufficient blood flow into the . Tadalis tablets 20mg relax the blood vessels in the increasing blood flow and causing an erection, which is the natural response to sexual stimulation. However, Tadalis tablets 20mg will only work if you are sexually aroused.