My ldl was only a little high but my ratio was poor. my gp thinks it's genetic and prescribed crestor 5 mg/day. this more than halved my ldl cholesterol. should i reduce to one every 2 days to reduce risks to my liver etc?

Please talk to the doctor who prescribed the medication. it is not a good idea to alter your medication without discussing it with your doctor.

As a board certified internist and cardiologist you ask a great question. Pay attention to the ratio of triglycerides to HDL. This is probably more important. Other higher concerned features are VLDL or ldl particle size. This needs an encompassing approach with inflammatory markers, family history, blood sugar parameters. Consider a coronary calcium test to risk stratify and red rice yeast OTC.