The most common statin side effects include: 1  Headache. 2  Difficulty sleeping. 3  Flushing of the skin.  Muscle aches, tenderness, or weakness 1  (myalgia) Drowsiness. 2  Dizziness. Nausea or vomiting.  Abdominal cramping 1  or pain. Bloating 2  or gas. 3  Diarrhea. Constipation.  Rash.