People who respond to the placebo effect have proteins in their blood that are linked to controlling inflammation, which may help to explain how a placebo makes us feel better
Source:
https://www.newscientist.com/article/2255163-blood-test-could-reveal-if-you-will-experience-the-placebo-effect/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home