Severe fatigue is not a common side effect of taking statins. However, a recent study from the Archives of Internal Medicine (June 2012) shows that the drug may lead to decreased energy levels. In a randomized clinical trial, researchers at the University of California at San Diego evaluated 1,016 patients who received either a low-dose statin or placebo. The patients initially reported their energy level and fatigue on exertion at baseline. Six months after the patients started taking statins, the researchers asked if there had been any changes from baseline, rating their changes on a 5-point scale ranging from much less to much more. The results reported that statins were associated with both decreased energy level and increased fatigue with exertion.