A
placebo ( ;
Latin , "I shall please" from , "I please") is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient. Sometimes patients given a placebo treatment will have a perceived or actual improvement in a medical condition, a phenomenon commonly called the
placebo effect or
placebo response. The placebo effect consists of several different effects woven together, and the methods of placebo administration may be as important as the administration itself.