Placebos are commonly thought of as fake treatments that people think are real. But they may be helpful even if you know they're fake. Tim Robberts/Getty Images hide caption toggle caption Tim Robberts/Getty Images Shots - Health News Is A Placebo A Sham If You Know It's A Fake And It Still Works? October 27, 2016 Most research on placebos involves people who think they're getting an active treatment, but aren't. But they may also work when people know full well they're getting a sham treatment.