👉 A placebo is a substance that, when given to a person who has no disease or condition, makes them believe they have it. The term "placebo" comes from Latin and means "a thing which one gives as an aid." In medicine, this refers to a drug or treatment that can be used to treat a patient without actually treating the disease or condition. In medical research, placebos are often used to test new drugs or treatments before they are approved for widespread use. They are usually