nocebo effect
noun
: the development of adverse side effects or worsening in the condition of a patient that occurs in response to medical treatment but cannot be considered due to the specific treatment used
With a nocebo effect, if test subjects believe there may be side effects, they often experience them. Again, expectations shape reality.—
Sanjay Gupta
Sanjay GuptaExamples of nocebo effect in a Sentence
Recent Examples on the Web
That’s the nocebo effect—the evil twin of the placebo.
—David Meade, Forbes.com, 18 July 2025
The nocebo effect is another important aspect of mindset.
—Jennifer C. Lovejoy, Scientific American, 7 Dec. 2022
Marino, who watched the video, told the San Diego Union-Tribune a nocebo effect could explain Faiivae's reaction since his symptoms did not suggest an overdose.
—Miriam Fauzia, USA TODAY, 25 Aug. 2021
The placebo effect also has a shadowy twin: the nocebo effect.
—Carl Engelking, Discover Magazine, 5 Oct. 2017
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
David Meade, Forbes.com, 18 July 2025
The nocebo effect is another important aspect of mindset.
—Jennifer C. Lovejoy, Scientific American, 7 Dec. 2022
Marino, who watched the video, told the San Diego Union-Tribune a nocebo effect could explain Faiivae's reaction since his symptoms did not suggest an overdose.
—Miriam Fauzia, USA TODAY, 25 Aug. 2021
The placebo effect also has a shadowy twin: the nocebo effect.
—Carl Engelking, Discover Magazine, 5 Oct. 2017
Cite this Entry
“Nocebo effect.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nocebo%20effect. Accessed 8 Sep. 2025.
Copy CitationMedical Definition
nocebo effect
noun
: the development of adverse side effects or worsening in the condition of a patient that occurs in response to medical treatment but cannot be considered due to the specific treatment used
With a nocebo effect, if test subjects believe there may be side effects, they often experience them. Again, expectations shape reality.—Sanjay Gupta, Chasing Life: New Discoveries In The Search For Immortality …
Sanjay Gupta, Chasing Life: New Discoveries In The Search For Immortality …The placebo effect has an evil twin: the nocebo effect, in which dummy pills and negative expectations can produce harmful effects.—Helen Pilcher, New Scientist
Helen Pilcher, New ScientistLove words? Need even more definitions?
Merriam-Webster unabridged
Share