Placebo

A placebo is a dummy intervention with no active ingredient, designed to look, taste, or feel like the real treatment so participants cannot tell them apart. Its purpose is to serve as a comparison that captures everything except the treatment's specific biological action: the placebo effect from expectation, the extra attention of being in a study, and the tendency of many conditions to improve on their own. The genuine added benefit of a treatment is the difference between the treatment and placebo groups, not the raw improvement in the treated group. When reading a study, check whether the control was a true placebo or merely no treatment, and whether the placebo was convincing enough to preserve blinding. Example: if a cold remedy group improves 60 percent but the placebo group improves 55 percent, most of the recovery came from time and expectation, and the remedy's real effect is small. Ask what the comparison group actually received.