An inactive substance, a tablet or a capsule, for example, that does not contain an active drug ingredient. For example, placebo pills may contain sugar. Placebos can be used in clinical trials (see Clinical trial) as control intervention when there is no standard treatment for the disease. In blinded clinical trials (see Blind study), placebos must look like the active treatment under study, so that participants (and researchers) can’t discern them from the active treatment.
