Answer: A placebo is anything that may seem to be a "real" treatment but actually isn't. They're used to determine if a treatment is treating patients.
Explanation:
A placebo is anything that seems to be a "real" medical treatment -- but isn't. It could be a pill, a shot, or some other type of "fake" treatment. What all placebos have in common is that they do not contain an active substance meant to affect health.
The placebo effect is defined as a phenomenon in which some people experience a benefit after the administration of an inactive "look-alike" substance or treatment. This substance, or placebo, has no known medical effect.
