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A placebo is a substance or medical procedure that resembles an actual treatment but does not actually act on a disease or medical condition; in effect it is a fake treatment, offered for experimental or other reasons. For some people, however, placebos can still have a positive or negative effect on symptoms, if only for a brief period of time.

What Is a Placebo?

A placebo can be any treatment or substance that appears to be genuine but isn't. Placebos do not generally have long-lasting effects and they do not cure diseases. Much of the placebo effect depends on a person’s expectations. If a person expects to feel relief, they just might. If a person fears side effects, those might occur. When the placebo effect is negative, it is sometimes referred to as the “nocebo effect.”

What is the purpose of a placebo?

When randomized, double-blind experiments became standard practice in the 20th century, placebos were used on control groups to test the effectiveness and potential side effects of new medications. However, subjects in the control groups began reporting effects despite taking a placebo. Since then, the power of placebos has been harnessed to treat a number of conditions, including rheumatism, multiple sclerosis, Crohn’s disease, epilepsy, colitis, acne, erectile dysfunction, and more.

What is the “placebo effect” in psychology?

A positive placebo effect is thought to occur as a result of believing a treatment is real, combined with the body’s natural ability to provide pain relief. In effect, a placebo can be a psychological remedy for a physical ailment. However, a placebo effect can also be negative, such as experiencing side effects from a medicine you’re not really taking.

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The Benefits and Limitations of Placebos
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While the effects are generally temporary, placebo treatments play a role in understanding the brain-mind-body connection in both medical practice and biomedical research. Placebos are often used in medical research to help determine if the effects of a new treatment are actually due to the treatment itself, rather than some other factor.

In a double-blind study, for instance, volunteers don’t know if they are getting the actual treatment or a placebo, so the results can be considered unbiased. Ethical guidelines have been established to prevent the misuse of placebo treatments.

How does the placebo effect impact the brain?

Several factors influence how well a placebo works, including the individual’s expectancy, their motivation to improve their health, external conditioning (e.g., advertising), and the brain’s ability to produce pain-relieving chemicals called endogenous opiates.

Is a placebo “fake” if it works?

A placebo may involve a “fake” treatment (e.g., placebo pills, saline injections, sham surgeries, etc.), but if it works, real physiological changes take place in the body.

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