Recent data suggest that aggressive lipid-lowering treatment results in significant reductions of atherosclerotic complications, ie, strokes, heart attacks, or peripheral vascular diseases. Thus, more patients will be titrated to higher doses of statins in order to reach the aggressive targets of low-density lipoprotein— cholesterol reduction. However, aggressive treatment with high statin doses has increased the risk of statin-induced myopathy. The incidence of myopathy in cohort studies and in randomized trials has been low, supporting the good safety profile of statin drugs. However, muscle effects seem to be more frequent in clinical practice. Of all statin users, approximately 1% to 5% suffers from muscular symptoms caused by medication. This potentially reduces the compliance toward treatment and number of patients reaching their treatment targets due to withdrawal of therapy. Thus, novel biomarkers are needed for prediction or improved diagnoses of statin-induced side effects. This would potentially increase the quality of life of patients and improve treatment results. Using lipidomic analysis, we found that the plasma lipidomic changes following simvastatin treatment correlate with the muscle expression of the arachidonate 5-lipoxygenase-activating protein. Intriguingly, these results suggest that the plasma lipidomic profile may serve as a highly sensitive biomarker of statin-induced metabolic alterations in muscle and may thus allow us to identify patients who should be treated with a lower dose to prevent a possible toxicity.