The nocebo effect is the opposite of the placebo effect. If your're told, and truly believe that a substance can make you ill or have negative side-effects, those side effects can occur even if there are no active ingredients at all.
The nocebo effect is the opposite of the placebo effect. If your're told, and truly believe that a substance can make you ill or have negative side-effects, those side effects can occur even if there are no active ingredients at all.