Statins are a group of drugs that have been used widely for the past decade to reduce blood cholesterol levels, and thereby reduce the risk of heart disease. They work by inhibiting the body's ability to synthesize cholesterol, and are very effective at doing so. Serum cholesterol levels may be reduced by more than 50% using the highest doses of these drugs. There is a substantial body of evidence showing that statins reduce the risk of coronary events including heart attacks, and that they may also be of benefit in reducing the risk of strokes.

The statins are proven to be very safe and generally do not give any major side effects. Reported side effects include mild generalised myopathy (muscle pains), and mild abnormalities of liver function. Only 2% of patients treated with statins have these effects. Despite this low prevalence, many doctors using statins do biochemical tests to screen for these side effects before commencing treatment and then repeat the tests after about four months. The adverse effects of the statins are rarely very serious. Very occasionally however, myopathy can be so severe as to cause a major breakdown of muscles (called rhabdomyolysis). This can lead to other complications including kidney damage. Of the many millions of patients on statins worldwide there have been reports of approximately 60 deaths related to this rare complication. Most of these have occurred when the statin is combined with another lipid lowering drug.

Some patients with high levels of blood cholesterol do not need statin treatment. Patients who have an under-active thyroid gland may have very high cholesterol levels and treatment with thyroid hormone may normalise cholesterol levels. High cholesterol levels may also be found in patients with kidney disease or gall bladder disease. These secondary causes of a high cholesterol level may need to be investigated before treatment with a statin is initiated.