clinical pharmacology
Placebos
Introduction
Placebos are inactive substances or interventions, most often used in controlled studies for comparison with potentially active drugs. The term placebo (Latin for “I will please”) initially referred to an inactive, harmless substance given to patients to make them feel better by the power of suggestion. More recently, sham interventions (eg, mock electrical stimulation or simulated surgical procedures in clinical trials) have also been considered placebos. The term is sometimes used for an active drug that is given solely for its placebo effect on a disorder in which the drug is inactive (eg, an antibiotic for patients with viral illness). 