They Knew the Pill Was Fake, but Their Memory Still Improved

The experiment involved 90 healthy older volunteers. They were divided into three groups. The first received nothing. The second took placebo pills but believed they were a real supplement meant to improve well-being and physical fitness. The third group also received empty pills, but they were honestly told that it was a placebo which could nevertheless trigger beneficial processes in the body through expectations and belief.

After three weeks, participants completed tests of short-term memory, attention, and physical endurance, and answered questions about stress, fatigue, and well-being.

The results were surprising. Both placebo groups showed significant improvement. Stress levels dropped most markedly in the group that knew the truth. Physical performance increased by 7–9%, while memory scores rose by 7–21% depending on the test. The effects were comparable to results from real training or cognitive exercises.

The scientists emphasize that the mind plays a huge role in the aging process. Expectations and beliefs can genuinely influence how the brain and body function. Open-label placebo appears to be an ethical and safe tool for supporting older adults.

Sources:

1. Universita Cattolica del Sacro Cuore. "They knew the pill was fake but their memory still improved." ScienceDaily (June 25, 2026).
2. Barbiani D. et al. "Placebo mechanisms in aging: A randomized controlled trial comparing deceptive and open-label placebos on psychological, cognitive, and physical functioning in older adults." International Journal of Clinical and Health Psychology (2026). DOI: 10.1016/j.ijchp.2026.100673.