Although a rare occurrence ...

Like all medications, CIALIS may have some side effects. The most common side effects with CIALIS are headache, upset stomach, back pain, and muscle aches. These side effects usually go away after a few hours. Patients who get back pain and muscle aches usually get it 12 to 24 hours after taking CIALIS. Back pain and muscle aches usually go away by themselves within 48 hours. Call your doctor or other healthcare professional if side effects continue to bother you. Although a rare occurrence, men who experience an erection for more than 4 hours (priapism) should seek immediate medical attention.

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