Why do statins need to be taken at bedtime?

Increased efficacy: The thought is that cholesterol formation in the liver is highest when sleeping, so a shorter acting statin would have the highest blood levels in the blood if taken at bedtime. Some statins that have a longer time in the blood, so less of an issue. According to their fda package inserts: pravachol, crestor, and Lipitor (atorvastatin) can be taken at any time. Zocor is reported to take in evening.