What is a "placebo"?

A placebo is a substance or treatment that resembles a real medical treatment but does not contain any active ingredients. It is often used in medical research and clinical trials to compare against the effects of actual medications or treatments. Placebos are designed to have no therapeutic effect on the patient, allowing researchers to evaluate the true effectiveness of the active treatment being studied. They are typically used in a way that ensures the patient is unaware of whether they are receiving the placebo or the actual treatment, to make sure that the study results are fair and not influenced by expectations or assumptions.