The Consumer Use Study of OTC Mevacor evaluated the ability of subjects to self-manage high levels of low-density lipoprotein (LDL) cholesterol by using a multifaceted cholesterol self-management program (the Mevacor Over-the-Counter Self-Management System; MOTC-SMS). This 26-week all-comers multicenter observational study was conducted in naturalistic storefront settings that used the fully functional MOTC-SMS to guide subjects' behavior. Of 3,316 subjects who evaluated the product (evaluators), 1,061 took >or=1 20-mg tablet of Mevacor OTC (users). Eighty-four percent of evaluators made appropriate initial use decisions. Most users demonstrated acceptable ongoing use behavior regarding treatment to goal, compliance/persistence, changes in health status, dietary patterns, and exercise habits. Throughout the study, 23 users (2%) demonstrated behavior that created the potential for suboptimal safety. After 26 weeks, median levels of LDL cholesterol were reduced by 25% among users who fasted. Of the 878 users who completed the study lipid test, 548 (62%) achieved the LDL cholesterol target goal (<130 mg/dl). Physician interactions were common. Mevacor OTC was well tolerated, with no observable adverse experiences from drug interactions or reports of myopathy. This actual use study demonstrates that the MOTC-SMS can effectively guide consumers to interact with health care professionals and to make appropriate initial and ongoing use decisions to manage their elevated levels of LDL cholesterol, with minimal potential or actual safety risk.