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
Encouraging a more thoughtful and grounded relationship with health information online could be a key step in mitigating the impact of the nocebo effect.
—
Peter Suciu,
Forbes.com,
27 Mar. 2025
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 data clearly indicated that a nocebo effect was occurring – in other words, participants were experiencing an entirely psychological phenomenon in which a harmless substance causes a harmful effect.
—
Elsbeth Sites,
Discover Magazine,
3 June 2014
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.
Peter Suciu,
Forbes.com,
27 Mar. 2025
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 data clearly indicated that a nocebo effect was occurring – in other words, participants were experiencing an entirely psychological phenomenon in which a harmless substance causes a harmful effect.
—
Elsbeth Sites,
Discover Magazine,
3 June 2014
Cite this Entry
“Nocebo effect.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nocebo%20effect. Accessed 5 Jul. 2026.
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
