Simvastatin side effects What are the possible Simvastatin side effects? Simvastatin side effects can run the gamut from mild to quite severe. The nuisance type of Simvastatin side effects include stomach discomfort, gas, bloating, heartburn, constipation, fatigue, faintness, headache, skin rash, general aches and pains, or flu like symptoms. The more severe Simvastatin side effects would include chest pain, muscle pain, tenderness, discolored dark urine, pungent urine, low grade fever, reddish colored stool, and yellowing of the eyes and skin (jaundice). This is only a partial list, so if you are considering Simvastatin some additional research should be in order. Simvastatin side effects - What is the most serious of all the side effects? The condition is known as rhabdomyolysis and it was less than ten years ago when the risk of this condition being caused by statin medications first came to light. Rhabdomyolysis is a painful condition that occurs when muscle death, from lack of essential cholesterol, cascades into kidney failure. The first indication that might be happening to you will be unexplained muscle tenderness, muscle weakness, fever combined with flu like symptoms, and/or dark colored urine.