Lipoprotein(a) [Lp(a)] is a cholesterol-carrying package in the blood stream that closely resembles low density lipoprotein (LDL) but has its own connection to the risk of having a heart attack or a stroke. The levels of Lp(a) in the blood are very strongly controlled by inheritance, and physicians can do very little to change Lp(a) in individuals with very high levels. A recent study of the effects of the diabetes drug, metformin (Glucophage) in women who had polycystic ovary disease and were insulin resistant demonstrated a large (40%) drop in Lp(a) levels in blood. This protocol will determine whether that result can be reproduced in non-diabetic patients with very high levels of Lp(a). Six subjects will be recruited. They will receive either placebo or metformin for eight weeks. They will be monitored at the start of each period, after four weeks of treatment, and then will have measurements of Lp(a) during the last week of each treatment period.