Statins are approved for use by all pilots, classes 1 and 2. Side effects are usually minimal, mainly a slight increase in muscle aching and stiffness, especially after significant exercise. This tends to decrease as time goes on. If that sort of side-effect is more troublesome or unacceptable then a change of brand (eg atorvastatin to pravastatin) is usually all that's required.
Certainly no need to be "a bit worried". A significantly raised cholesterol would be of MUCH more concern ! !