Cholesterol-lowering statins, prescribed to some 30 million Americans, have begun to lose a bit of their luster. A set of warnings issued in February by the US Food and Drug Administration require that statin labels include information about the possibility of cognitive side effects such as memory loss and confusion, and an increase in blood sugar levels that could trigger type 2 diabetes. Already on manufacturer websites, the warnings will soon be appearing on the package inserts that accompany prescriptions.