Do all clinical trials involve a placebo?
No, not all clinical trials involve the use of placebo (an inactive substance that looks like the drug being tested). Some Phase III trials may compare investigational therapies to standard therapy used to treat the disease in question. However, in the case of some illnesses, no standard treatment exists therefore, in order to insure that the investigational drug is truly safe and effective the FDA may require that it be compared to placebo. When a placebo is used, trial participants are informed before they agree to take part in the trial that there is a chance that they will not receive the investigational drug, but may receive placebo instead.
