The Study
Open-label placebo vs double-blind placebo for irritable bowel syndrome: a randomized clinical trial
This study showed that telling people they're taking a sugar pill (and not hiding it) still helped some people with stomach pain. But it doesn't prove sugar pills work for everyone — just for the kind of people who signed up for this experiment.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
People with IBS took pills they were told were sugar pills, and many felt better—even though they knew the pills had no medicine in them.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 565 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—this means a large portion of IBS patients can get real relief from a treatment that doesn’t trick them, which is ethical and could help people who don’t respond to drugs.
- 270% of people taking open-label placebo felt significantly better (50-point drop on symptom scale), same as those taking blinded placebo.
- 3Those taking no pills improved less (54%).
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Pain
Year
2021
Authors
A. Lembo, J. Kelley, J. Nee, S. Ballou, J. Iturrino, Vivian Cheng, Vikram Rangan, J. Katon, William Hirsch, I. Kirsch, Kathryn T. Hall, Roger B. Davis, T. Kaptchuk
Related Content
Claims (5)
Patients who know they are receiving a placebo still experience measurable improvements in their symptoms.
In adults with irritable bowel syndrome, higher expectations about peppermint oil are linked to symptom improvement, but higher expectations about a placebo are not. This suggests that the improvement seen with placebo is tied to specific beliefs about peppermint oil, not general positive attitudes.
In adults with moderate to severe irritable bowel syndrome, taking placebo pills openly three times a day for six weeks reduces symptom severity by an average of 90.6 points on the IBS Severity Scoring System, which is a larger reduction than no treatment and similar to the reduction seen with hidden placebo pills.
In adults with irritable bowel syndrome, both open-label and double-blind placebos led to a 70% rate of clinically meaningful symptom improvement, showing no difference in effectiveness based on whether patients knew they were receiving a placebo.
Among adults with irritable bowel syndrome who are told they are receiving a placebo, about 70% experience a 50-point drop in symptom severity scores on a standardized scale.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.