Placebo effects are real because when we believe we are going to get better, we often do.

When our body expects to get better, it sends out messages to start the healing process. Hormones, immune cells, and neurochemicals are all released. The placebo effect provides proof that when we believe we are going to get better or feel better, we often do. It’s a testament to the power of the mind to affect the body with mere suggestion. (Location 436)