What causes statin side effects?

It's unclear what causes statin side effects, especially muscle pain.

Statins work by slowing your body's production of cholesterol. Your body produces all the cholesterol it needs by digesting food and producing new cells on its own. When this natural production is slowed, your body begins to draw the cholesterol it needs from the food you eat, lowering your total cholesterol.

Statins may affect not only your liver's production of cholesterol but also several enzymes in muscle cells that are responsible for muscle growth. The effects of statins on these cells may be the cause of muscle aches.