Placebo

In a placebo-controlled trial, patients are randomly allocated to groups. One group receives the drug, while another receives a placebo that looks like the treatment but contains none of its active drug. The placebo group acts as a control.

In some patient trials, one group receives the active drug and another receives a placebo, a treatment containing no active drug. Comparing the groups helps researchers judge whether the active drug provides a benefit beyond changes seen without it.