Placebo

The simple fact of receiving a treatment may have an influence on symptoms, regardless of the biological effects of the administered substance. This is called a placebo effect. In clinical experiments, it is essential to determine the effects linked to the treatment and those that are linked to the placebo effect. Therefore, it is common practice to compare the effects of the substance to be tested with those of a preparation with no biological effect but which looks exactly the same at first glance. This is a placebo. Neither the person taking part in the experiment nor the experimenter know whether the product administered corresponds to the drug or vaccine to tested or the placebo. This is called a double-blind test.