Chelation therapy is a safe, painless, non-surgical medical procedure used to remove undesirable heavy metals such as lead, mercury, nickel, copper, cadmium, and others from the body. More recently Chelation Therapy has also been used to reverse symptoms of atherosclerosis or arteriosclerosis (hardening of arteries) by removing the obstructive plaque that has built up in circulatory system. Atherosclerosis is caused by many complex factors including the abnormal accumulation of metallic elements in the body.