A placebo is a treatment that appears real but is designed to have no therapeutic benefit. It can be a sugar pill, a water or saltwater injection, or even a fake surgical procedure. The placebo effect is triggered by the persons belief in the benefit from the treatment and their expectation of feeling better, rather than the characteristics of the placebo. Researchers use placebos during studies to help them understand what effect a new drug or some other treatment might have on a particular condition. Placebos are often used in clinical trials as an inactive control so that researchers can better evaluate the true overall effect of the experimental drug treatment under study. Placebos can produce results even when people know they are taking a placebo. The placebo effect is mainly on symptoms rather than the actual disease. Some people who take a placebo feel better, and some others develop "side effects". The placebo effect can have therapeutic benefits, and it involves a complex neurobiological reaction that includes everything from increases in feel-good neurotransmitters, like endorphins and dopamine, to greater activity in certain brain regions linked to moods, emotional reactions, and self-awareness.