Adverse events with statins are rare and infrequent, but they do manifest themselves is a small percentage of the patient population (usually less than 3% as seen in most product PIs). The most frequent complaint is myalgia (muscle pain), though this can be attributed to a number of different things outside of the statin. The worst case scenario for taking a statin is rhabdomyolisis (muscle wasting), but this is extemely, extemely rare and physicians monitor for any indicators (especially since Baycol was removed from the market years ago). If you have severe liver or renal disease then you may want to stay away from statins as well. Otherwise, many clinicians claim that statins have pleitropic benefits in addition cholesterol lowering and reducing stroke and MIs (benefits such as improving alzheimers, breast cancer etc, though this has not been clincally proven). Bottom line is that your physician would not put you on anything that is harmful. All the statins available on the market have been proven safe in clinical trials and are closely monitored by the FDA.