Bad cholesterol is like impurities in tap water that are deposited and lead to narrowing of blood vessels. Statin is a scavenger to remove impurities (cholesterol) from blood vessels and reduce them to prevent narrowing of blood vessels. Statin not only lowers bad cholesterol, but also lowers triglycerides and raises good cholesterol, and also improves endothelial function, anti-inflammation, stabilizes and decreases plaque, which can reduce the risk of coronary heart disease by 30% to 50%. Although statin use causes elevated liver and muscle enzymes and an increased risk of diabetes, recent research published in the British Medical Journal confirms that the benefits of statin prevention of cardiovascular disease far outweigh the side effects. What should I do if I experience adverse effects from taking a statin? Before starting statin therapy, if a patient has persistent unexplained myalgia, it is recommended to check creatine kinase (CK): if CK is 5 times above the upper limit of normal, repeat the measurement in 5 to 7 days and if it is still above 5 times, do not start statin therapy; if it is less than 5 times elevated, start statin therapy at a low dose. Seek prompt medical attention when muscle symptoms such as myalgia, fatigue or weakness occur. If previous statin therapy was tolerated, new onset of myalgia or muscle weakness should first be ruled out as a non-statin related factor. In contrast, routine monitoring of CK is not necessary for patients who are asymptomatic on statin therapy. liver enzymes should be checked before initiating statin therapy and should be rechecked at 3 months and 1 year of treatment. If liver enzymes are elevated less than three times the upper limit of normal, they generally do not affect statin therapy and do not need to be discontinued. It is not necessary to discontinue statin therapy if blood glucose or glycated hemoglobin is elevated during statin therapy. If a patient cannot tolerate statin therapy due to adverse reactions during statin therapy, the following strategies are recommended: stopping the drug can be considered for severe adverse reactions, restarting it after the symptoms disappear and observing the correlation between symptoms and statin; less severe can be done by reducing the dose while ensuring the intensity; alternatively, the type of statin can be changed to reduce the intensity of treatment. The available evidence does not recommend taking coenzyme Q10 or vitamin D to relieve muscle symptoms.