A placebo-controlled trial is a type of clinical study designed to test the effectiveness of a new treatment. In this trial, one group of participants receives the actual treatment, while another group receives a placebo, which is an inactive substance that looks like the real treatment. This helps researchers determine if the treatment works better than no treatment at all. By comparing the outcomes of both groups, scientists can assess the true effects of the treatment. This method helps eliminate bias, as participants and researchers may not know who is receiving the treatment or the placebo, ensuring more reliable results.