The Placebo Effect: When Belief Changes Biology
- Kei Dino
- Aug 13
- 3 min read
"The power which a man's imagination has over his body to heal it or make it sick is a force which none of us is born without." Mark Twain
What if the most powerful ingredient in a pill wasn't the medicine, but your expectations?
In many research projects, scientists employ a pill that affects the body based on what the recipient is told about it. This pill is considered a placebo: something that triggers a genuine response to a non-therapeutic treatment. The placebo effect is an authentic reaction stimulated by a person's belief, expectations, and social cues rather than by chemicals.
While scientists cannot fully understand how placebos work, it is known that they involve the brain’s ability to release natural chemicals that mimic the responses typically produced by therapeutic methods. This stems from higher cognitive centers regulating lower sensory and physiological functions. When the body experiences physical pain, the brain typically generates natural morphine-like substances, which act like pain medication. Additionally, neurotransmitter systems like dopamine---which plays a vital role in the brain's reward system---regulate individuals' perception of reality. Yet, there are also other factors, including social and personal conditioning, that contribute to this phenomenon. From mood-enhancing hormones to immense activity in specific brain areas connected to expectation, emotion, and reward, the placebo effect is considered a neurobiological phenomenon.
There have been numerous cases where placebos have benefited patients. In a study of Open-Label Placebo Treatment for Cancer-Related Fatigue, it was proven that those who took the placebo during the first three weeks experienced less fatigue than those who only received their normal treatment. In addition, even after the three weeks were over, the placebo group continued to benefit, and the standard treatment group also experienced improvements in fatigue after taking the pill.
Researchers use placebos to identify the actual improvements from a drug. Essentially, it acts as the experiment’s control variable. Placebos are integrated widely in trials and acknowledged as the ‘gold standard’ to evaluate whether a treatment is effective. Additionally, it helps scientists test the drug’s true contribution towards the participants or patients; without it, treatment would seem more effective than it actually is.
Considering all that the placebo effect can do, there is one question researchers have asked: can negative expectations towards a drug cause the same consequences in patients? The answer is yes---there have been multiple occurrences where people have experienced negative side effects despite having received an inactive substance. This effect is called the ‘placebo effect’s evil twin’ or, more often, the Nocebo effect. Just like the placebo effect, the brain influences the body through expectations. For example, if your doctor says an injection will hurt, the body may perceive it to be painful, whereas the pain may be less intense if the doctor says otherwise.
Ultimately, the placebo effect shows us the relationship between the mind and the body and how we can use this knowledge to our advantage. Our mindset is one of the biggest impactors on our health. Just like a pill, the seed of optimism we carry into our lives gives us the power over our body and how we choose to treat it.
References
Cherry, K. (2011). How the Placebo Effect Works in Psychology. In Verywell Mind. Verywellmind. https://www.verywellmind.com/what-is-the-placebo-effect-2795466
Clinic, C. (2024). What’s the Nocebo Effect? Examples and Effects on Your Health. In Cleveland Clinic. https://health.clevelandclinic.org/nocebo-effect
Helmenstine, A. (2023). Placebo Effect - What It Is and How It Works. In Science Notes and Projects. https://sciencenotes.org/placebo-effect-what-it-is-and-how-it-works/
Hoenemeyer, T. W., Kaptchuk, T. J., Mehta, T. S., & Fontaine, K. R. (2018). Open-Label Placebo Treatment for Cancer-Related Fatigue: A Randomized-Controlled Clinical Trial. Scientific Reports, 8(1). https://doi.org/10.1038/s41598-018-20993-y
How Placebos Work: The Science Behind the Effect. (2025). In ScienceInsights. https://scienceinsights.org/how-placebos-work-the-science-behind-the-effect/
LeWine, H. (2024). The power of the placebo effect. In Harvard Health. Harvard Health Publishing. https://www.health.harvard.edu/newsletter_article/the-power-of-the-placebo-effect
Saling, J. (2022). What Is the Placebo Effect? In WebMD. https://www.webmd.com/pain-management/what-is-the-placebo-effect
Why Are Placebos Used in Clinical Trials: Bias and Biology. (2026). In ScienceInsights. https://scienceinsights.org/why-are-placebos-used-in-clinical-trials-bias-and-biology/
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© 2026 Kaylyn K. | All rights reserved
Originally published at themedtales.com
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