Cialis is an oral phosphodiesterase inhibitor used in the treatment of treatment of impotence (erectile Dysfunction, also known as ED). Common adverse effects of Cialis include sexual dysfunctions such as respiratory distress, flushing (also called redness or warmth on the throat, face, or the torso), stomach upset, headaches, diarrhea, flu-like symptoms (seeing or experiencing a cold coming on, sweats, chills and more) dizziness, muscle or back pain. These side effects may be caused by the interaction between calcium and serotonin. Apart from that, it hasn't been proven to trigger heart attacks or any other health issues. However, before you begin using Cialis you must know the ingredients of this supplement.