what is placebo in clinical trials

A placebo is an inactive substance that looks and tastes like the drug being tested but has no effect on the disease the new drug is intended to treat. Placebos are used in some clinical trials, which are research studies done with volunteers. Whenever possible, clinical trials compare a new treatment for a specific condition to the standard treatment for that condition. When there is no standard treatment available, scientists may compare the new treatment to a placebo, which looks like the drug or treatment being tested but isn’t meant to actually change anything in your body. A trial that uses a placebo is described as a “placebo-controlled trial.” In this type of study, the test group receives the experimental treatment, and the control group receives the placebo. Placebos are not used if an effective treatment is already available or if you would be put at risk by not having effective therapy. Researchers may use placebos in cancer clinical trials. Placebos are rarely used in cancer treatment clinical trials. If placebos are used, it is likely because no standard treatment exists. Or they may be used in a trial that compares standard treatment plus a placebo, with standard treatment plus the study treatment. The use of placebos in controlled clinical trials must be justified by a positive risk-benefit analysis, and subjects must be fully informed of the risks involved in assignment to the placebo group.