Evidence review · Neuroscience & research
Hypnosis and Science: What Research Shows
A clear, evidence-based review: where hypnosis is well supported, where the limits are, what happens in the brain, and which bodies and guidelines recognise it.
Jan Mion
Hypnotherapist EZC · 1,500+ training hours · in private practice since 2015
- Reference edition
- 10 August 2026
- Literature checked
- 20 October 2026
Based on meta-analyses, Cochrane reviews, guidelines and official reports. Every figure was checked against its original source, linked below.
Short answer
What does research say about hypnosis?
Hypnosis is a well-studied method. Neuroimaging studies, such as those from Stanford University, show measurable changes in brain activity during trance. The evidence is strongest for pain and medical procedures, and several guidelines recommend gut-directed hypnosis for irritable bowel syndrome. Results for anxiety are promising; for smoking cessation, an advantage over other methods has not been established. How well hypnosis works also depends on how strongly a person responds to suggestion.
Research shows: hypnosis is not imagination, but a state of focused attention with measurable changes. How strongly it works depends on the person and the topic.
Evidence atlas
What studies say about individual applications
Clinical trials and meta-analyses examine hypnosis across medical and psychological fields. The strength of the evidence varies by topic.
| Application | Assessment | What research shows | Limits & context |
|---|---|---|---|
| Medical procedures | Well supported | A meta-analysis of 34 randomised trials with 2,597 patients found less emotional distress and pain, slightly less medication and shorter procedures. The largest review to date (Geneva University Hospitals, 142 studies, 9,238 patients) confirms less anxiety, pain and postoperative nausea.[14][15][2] | Whether hypnosis reduces the need for anaesthetics and painkillers is open: some trials show it, but the Geneva review could not confirm it. Many studies are of limited quality. |
| Clinical pain | Well supported (medium effects) | Across 42 controlled studies, hypnosis reduced clinical pain with a medium effect size (g = 0.60): the average person receiving hypnosis had less pain than about 73% of controls. For chronic musculoskeletal and neuropathic pain the effect was moderate and only statistically reliable from 8 sessions.[3][22][23] | Long-term data are limited. How strongly someone responds to suggestion clearly affects the result. |
| Irritable bowel syndrome | Recommended in guidelines | In a meta-analysis of 8 randomised trials, gut-directed hypnosis gave 54% of patients adequate long-term relief. On average, for every 5 people treated, one more reached adequate relief than without hypnosis.[18][4][19][20] | British and US guidelines recommend it, on low and very low quality evidence respectively. Relief does not mean being symptom-free. |
| Anxiety | Promising | A meta-analysis of 17 controlled comparisons found a clear reduction in anxiety symptoms (d = 0.79), strongest when hypnosis was combined with other psychological treatments.[13][10] | The studies are small and many did not involve clinically diagnosed anxiety disorders. In 2006 the German Scientific Advisory Board for Psychotherapy could not accept any of the anxiety studies submitted. |
| Smoking cessation | Unclear, similar to CBT | According to a Cochrane review, it is not established that hypnosis helps people stop smoking more than other support; any benefit is small at most. In a German trial with 360 people, hypnosis worked as well as cognitive behavioural therapy: 15.0% vs 15.6% continuously smoke-free at 12 months.[6][16] | Most studies have methodological weaknesses. In both groups of the German trial, the large majority did not stay continuously smoke-free. |
| Sleep | Preliminary | In a University of Zurich study, a hypnotic suggestion increased deep sleep by 81% in highly suggestible women, measured during a 90-minute nap. Reviews find positive results in roughly half of the studies.[17][37][7] | In people with low suggestibility, deep sleep actually decreased after the same suggestion. Study quality is mostly low. |
Interpreting the research
What the research says about hypnosis
Modern research examines hypnosis on several levels, from brain activity to clinical outcomes.
Measurable phenomenon
During hypnosis, brain activity and the interplay between brain networks change measurably. Which patterns are typical has not yet been settled.
Early mechanisms
Hypnotic suggestions can, for example, change how unpleasant a pain feels, together with activity in the anterior cingulate cortex. There is not yet a complete model of how hypnosis works.
Clinical efficacy
For pain and medical procedures, hypnosis usually outperforms control conditions in controlled trials. For other topics the evidence is thinner.
Recognition
The German Scientific Advisory Board for Psychotherapy recognised hypnotherapy for two areas of application, several IBS guidelines recommend gut-directed hypnosis, and Switzerland has a medical certificate of competence.
Brain research
What modern brain research shows
Neuroimaging (fMRI and PET) shows that brain activity changes measurably in trance. It has not found a single “trance pattern” so far, but several findings show that hypnosis is more than imagination or role-play.
Stanford University · fMRI
Attention and self-awareness
What the study showed
57 people, selected from 545 as very high or very low in hypnotizability. During hypnosis, activity in the dorsal anterior cingulate cortex (part of the “salience network”) decreased, coupling between the prefrontal cortex (DLPFC) and the insula increased, and coupling with the default mode network decreased.
Context
The researchers interpret this as focused attention, better control of bodily and emotional responses, and less self-monitoring. It is a single study of extreme groups.
Meta-analysis · neuroimaging
What imaging studies have in common
What the meta-analysis showed
Few patterns were stable across studies. The most consistent was activation of the lingual gyrus, a region involved in mental imagery.
Context
Hypnosis changes brain activity, but in different ways depending on the suggestion and the person. A single “neural signature of trance” has not been established.
Montréal · PET · Science
Pain intensity and suffering, separated
What the study showed
Hypnotic suggestions changed how unpleasant a heat stimulus felt, but not how intense it was. Activity in the anterior cingulate cortex changed accordingly; the primary somatosensory cortex did not.
Context
A clue to why hypnosis often reduces mainly the suffering caused by pain. A small laboratory study with healthy volunteers.
Harvard & Stanford · PET
More than role-play
What the study showed
Eight highly hypnotizable people were asked under hypnosis to see colour in a grey image. The colour areas of the brain became active, in the left hemisphere only under hypnosis.
Context
The authors conclude that hypnosis is a psychological state with its own neural correlates, not just the result of adopting a role. A very small sample.
Recognition and guidelines
Who recognises and recommends hypnosis
In 2006 the German Scientific Advisory Board for Psychotherapy (WBP) recognised hypnotherapy as scientifically established for adults in two areas of application: psychological factors in physical illness, and addiction (with evidence for smoking cessation and methadone withdrawal). For anxiety disorders, and as a training method for psychotherapists, the evidence was not sufficient at the time.[10]
For irritable bowel syndrome, several guidelines recommend gut-directed hypnosis: the British Society of Gastroenterology (strong recommendation, low quality evidence), the American College of Gastroenterology (conditional recommendation, very low quality evidence) and the UK’s NICE when medication has not helped after 12 months. The German S3 guideline recommended it “where indicated”; its validity expired in 2026.[19][20][21][5]
A review in the Deutsches Ärzteblatt rates medical hypnosis as a safe and effective complementary method for medical procedures and irritable bowel syndrome.[33]
The Society of Psychological Hypnosis (Division 30 of the American Psychological Association) published a scientific definition of hypnosis in 2014/15: a state of consciousness involving focused attention and an enhanced capacity for response to suggestion.[12]
In Germany, statutory health insurance covers hypnosis as an individual treatment within psychosomatic primary care, up to 12 sessions. In Austria, hypnosis psychotherapy (Hypnosepsychotherapie) is a state-recognised psychotherapy method.[35][36]
Switzerland
Hypnosis research and recognition in Switzerland
Hypnosis is also researched in Switzerland, for example at the University of Zurich (sleep), Geneva University Hospitals (anaesthesia) and in Lugano (MRI and claustrophobia).
Medical certificate of competence
Physicians with a specialist title can obtain the SIWF-recognised “Certificate of competence in medical hypnosis SMSH” (at least 3 years, 360 hours). The SIWF describes medical hypnosis as an effective method documented in numerous scientific studies.[34]
University of Zurich: sleep
After a hypnotic suggestion to sleep more deeply, deep sleep rose by 81% in highly suggestible young women, measured during a nap. In people with low suggestibility it decreased in a follow-up study.[17][37]
Geneva University Hospitals: anaesthesia
The largest review so far of hypnosis around medical procedures (142 studies, 9,238 patients) confirms less anxiety, pain and nausea. Whether hypnosis lowers the need for anaesthetics is still open.[15]
Lugano: MRI and claustrophobia
All 40 patients who had previously had to abort an MRI scan completed it with hypnosis. A small retrospective case series without randomisation.[38]
Safety
What is known about safety
In registered clinical trials, no serious adverse events were found that were likely caused by hypnosis; milder ones occurred in 0.47% of participants. Many trials report side effects incompletely, however. Two meta-analyses found no difference in side effects between hypnosis and control treatments.[30][33]
In a survey of 691 clinicians from 31 countries, 55% had encountered adverse effects, generally short-lived and very rarely serious. The German Scientific Advisory Board for Psychotherapy lists acute psychosis and severe personality disorders as contraindications.[31][10]
Hypnosis is not a truth serum. Under suggestion, false memories can form; in one study they persisted for at least two weeks, and reviews advise caution with regression work. I have helped people remember forgotten passwords, for example for a Bitcoin wallet. But remembering in trance does not work like looking at a photograph: what comes up can mix with imagination. With a password you know immediately whether it is right; with memories of life events, that usually cannot be checked.[32][11]
- Does not involve medication or chemical substances.
- You stay responsive and can stop at any time.
- Combines well with medical and psychological treatment.
- Does not replace medical assessment or treatment.
- Guided by an experienced Hypnotherapist EZC.
Evidence and practice
Combining research and clinical experience
Evidence
Scientific foundation
Research provides the foundation: it shows where hypnosis is well supported, where its limits are and what happens in the brain.
Experience
Over 8,000 individual sessions
With over 10 years of practice and more than 8,000 sessions, I apply these findings to your personal goals.
Transparency
Scientific standard of this review
The goal is a reliable and accessible overview of current international hypnosis research.
- Literature check: October 2026.
- Focus on meta-analyses, Cochrane reviews, guidelines and official reports.
- Individual studies only where they show a finding particularly clearly, each with its limits.
- Clear separation of mechanism, clinical efficacy and recognition.
- Every figure was checked against the abstract, full text or official document.
Methodological limit: This overview is a curated summary, not a systematic review. It does not replace medical assessment or personal advice.
Cite this page
Suggested citation
Mion, Jan (2026): Hypnosis and science: what research shows. Evidence review. Mion Hypnose. https://janmion.ch/en/hypnosis-science
References
Sources and further reading
Direct links to original studies, PubMed records and official documents.
Rosendahl J, Alldredge CT, Haddenhorst A. Meta-analytic evidence on the efficacy of hypnosis for mental and somatic health issues: a 20-year perspective. Frontiers in Psychology. 2024;14:1330238. Umbrella Review, 49 Metaanalysen.
Walter N, Torres Leyva M, Hinterberger T, Rupp M, Loew T, Lambert-Delgado A, Cobián Mena AE. Hypnosis as a non-pharmacological intervention for invasive medical procedures: a systematic review and meta-analytic update. Journal of Psychosomatic Research. 2025;192:112117. 20 RCTs mit 1’250 Teilnehmenden.
Milling LS, Valentine KE, LoStimolo LM, Nett AM, McCarley HS. Hypnosis and the Alleviation of Clinical Pain: A Comprehensive Meta-Analysis. International Journal of Clinical and Experimental Hypnosis. 2021;69(3):297–322. 42 Studien.
Adler EC et al. Gut-Directed Hypnotherapy for Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis. Neurogastroenterology & Motility. 2025;37(7):e70037. 12 Studien, 1’158 Teilnehmende.
DGVS und DGNM. S3-Leitlinie Reizdarmsyndrom: Definition, Pathophysiologie, Diagnostik und Therapie. AWMF-Registernummer 021-016. Version 2021/2022, seit 2026 abgelaufen.
Barnes J, McRobbie H, Dong CY, Walker N, Hartmann-Boyce J. Hypnotherapy for smoking cessation. Cochrane Database of Systematic Reviews. 2019;6:CD001008. 14 Studien, 1’926 Teilnehmende.
Chamine I, Atchley R, Oken BS. Hypnosis Intervention Effects on Sleep Outcomes: A Systematic Review. Journal of Clinical Sleep Medicine. 2018;14(2):271–283. 24 Studien.
Jiang H, White MP, Greicius MD, Waelde LC, Spiegel D. Brain Activity and Functional Connectivity Associated with Hypnosis. Cerebral Cortex. 2017;27(8):4083–4093. Veröffentlicht 2016.
Landry M, Lifshitz M, Raz A. Brain correlates of hypnosis: A systematic review and meta-analytic exploration. Neuroscience & Biobehavioral Reviews. 2017;81:75–98.
Wissenschaftlicher Beirat Psychotherapie. Gutachten zur wissenschaftlichen Anerkennung der Hypnotherapie. Deutsches Ärzteblatt PP. 2006;6:285–288.
Leo DG, Bruno D, Proietti R. Remembering what did not happen: the role of hypnosis in memory recall and false memories formation. Frontiers in Psychology. 2025;16:1433762. Literaturübersicht.
Elkins GR, Barabasz AF, Council JR, Spiegel D. Advancing research and practice: the revised APA Division 30 definition of hypnosis. International Journal of Clinical and Experimental Hypnosis. 2015;63(1):1–9.
Valentine KE, Milling LS, Clark LJ, Moriarty CL. The efficacy of hypnosis as a treatment for anxiety: a meta-analysis. International Journal of Clinical and Experimental Hypnosis. 2019;67(3):336–363. 15 Studien, 17 Vergleiche.
Tefikow S, Barth J, Maichrowitz S, Beelmann A, Strauss B, Rosendahl J. Efficacy of hypnosis in adults undergoing surgery or medical procedures: a meta-analysis of randomized controlled trials. Clinical Psychology Review. 2013;33(5):623–636. 34 RCTs, 2’597 Patientinnen und Patienten.
Lahoud MJ, Gurary ST, Elia N. Hypnosis for anaesthetists: a systematic review and meta-analyses. Anaesthesia. 2026;81(1):103–115 (online 2025). 142 Studien, 9’238 Patientinnen und Patienten.
Batra A, Eck S, Riegel B, Friedrich S, Fuhr K, Torchalla I, Tönnies S. Hypnotherapy compared to cognitive-behavioral therapy for smoking cessation in a randomized controlled trial. Frontiers in Psychology. 2024;15:1330362. 360 Teilnehmende.
Cordi MJ, Schlarb AA, Rasch B. Deepening sleep by hypnotic suggestion. Sleep. 2014;37(6):1143–1152. Universität Zürich, 70 Teilnehmerinnen.
Schaefert R, Klose P, Moser G, Häuser W. Efficacy, tolerability, and safety of hypnosis in adult irritable bowel syndrome: systematic review and meta-analysis. Psychosomatic Medicine. 2014;76(5):389–398. 8 RCTs, 464 Patientinnen und Patienten.
Vasant DH, Paine PA, Black CJ, et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut. 2021;70(7):1214–1240.
Lacy BE, Pimentel M, Brenner DM, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. American Journal of Gastroenterology. 2021;116(1):17–44.
National Institute for Health and Care Excellence (NICE). Irritable bowel syndrome in adults: diagnosis and management (CG61), Empfehlung 1.2.3.1. London: NICE, 2008, zuletzt aktualisiert 2017.
Langlois P, Perrochon A, David R, et al. Hypnosis to manage musculoskeletal and neuropathic chronic pain: A systematic review and meta-analysis. Neuroscience & Biobehavioral Reviews. 2022;135:104591. 9 RCTs, 530 Teilnehmende.
Thompson T, Terhune DB, Oram C, et al. The effectiveness of hypnosis for pain relief: A systematic review and meta-analysis of 85 controlled experimental trials. Neuroscience & Biobehavioral Reviews. 2019;99:298–310. 3’632 gesunde Freiwillige, Laborschmerz.
Acunzo DJ, Terhune DB. A Critical Review of Standardized Measures of Hypnotic Suggestibility. International Journal of Clinical and Experimental Hypnosis. 2021;69(1):50–71.
Piccione C, Hilgard ER, Zimbardo PG. On the degree of stability of measured hypnotizability over a 25-year period. Journal of Personality and Social Psychology. 1989;56(2):289–295. 50 Teilnehmende.
Gorassini DR, Spanos NP. A social-cognitive skills approach to the successful modification of hypnotic susceptibility. Journal of Personality and Social Psychology. 1986;50(5):1004–1012.
Bates BL. The effect of demands for honesty on the efficacy of the Carleton Skills-Training program. International Journal of Clinical and Experimental Hypnosis. 1992;40(2):88–102.
Rainville P, Duncan GH, Price DD, Carrier B, Bushnell MC. Pain affect encoded in human anterior cingulate but not somatosensory cortex. Science. 1997;277(5328):968–971.
Kosslyn SM, Thompson WL, Costantini-Ferrando MF, Alpert NM, Spiegel D. Hypnotic visual illusion alters color processing in the brain. American Journal of Psychiatry. 2000;157(8):1279–1284. 8 Teilnehmende.
Bollinger JW. The Rate of Adverse Events Related to Hypnosis During Clinical Trials. American Journal of Clinical Hypnosis. 2018;60(4):357–366. Auswertung von ClinicalTrials.gov.
Palsson OS, Kekecs Z, De Benedittis G, et al. Current Practices, Experiences, and Views in Clinical Hypnosis: Findings of an International Survey. International Journal of Clinical and Experimental Hypnosis. 2023;71(2):92–114. 691 Fachpersonen aus 31 Ländern.
Sheehan PW, Statham D, Jamieson GA. Pseudomemory effects over time in the hypnotic setting. Journal of Abnormal Psychology. 1991;100(1):39–44. 110 Teilnehmende.
Häuser W, Hagl M, Schmierer A, Hansen E. The Efficacy, Safety and Applications of Medical Hypnosis. Deutsches Ärzteblatt International. 2016;113(17):289–296.
Schweizerisches Institut für ärztliche Weiter- und Fortbildung (SIWF). Fähigkeitsprogramm Medizinische Hypnose (SMSH). Bern: SIWF, 1. Januar 2023.
Gemeinsamer Bundesausschuss (G-BA). Psychotherapie-Richtlinie, §§ 26 und 31. Fassung vom 21. August 2025, in Kraft seit 11. November 2025.
Bundesministerium für Arbeit, Soziales, Gesundheit, Pflege und Konsumentenschutz (Österreich). Patientinnen- und Patienten-Information über die psychotherapiewissenschaftlichen Ausrichtungen. Stand 2. Dezember 2024. Abschnitt 2.6 Hypnosepsychotherapie.
Cordi MJ, Rasch B. Systematic decrease of slow-wave sleep after a guided imagery designed to deepen sleep in low hypnotizable subjects. Journal of Sleep Research. 2021;30(3):e13168. Universität Zürich.
Rizzo S, Ferrera N, Pravatà E, Guggenberger R, Stern S, Del Grande F. Is hypnosis a valid alternative to spontaneous breathing general anesthesia for claustrophobic patients undergoing MR exams? A preliminary retrospective study. Insights into Imaging. 2021;12:83. Retrospektive Studie, EOC/USI Lugano, 40 Patientinnen und Patienten mit Hypnose.
Gfeller JD, Lynn SJ, Pribble WE. Enhancing hypnotic susceptibility: interpersonal and rapport factors. Journal of Personality and Social Psychology. 1987;52(3):586–595.
Glossary
Terms Explained
- Hypnosis
- A state of focused attention characterized by heightened activity of the unconscious mind. A direct synonym for the state of hypnosis is hypnotic trance.
- Hypnotizability
- A person's overall responsiveness to hypnosis, encompassing both susceptibility and suggestibility.
- Suggestibility
- The degree to which a person is open to receiving and acting upon suggestions.
- Alpha State
- A brainwave state of 8–13 Hz associated with relaxed, light trance and calm alertness.
Frequently asked questions
Scientific facts at a glance
Is hypnosis scientifically studied?
Yes. One 2024 review alone covered 49 meta-analyses with 261 studies. Neuroimaging shows measurable changes in the brain. The evidence is strongest for pain and medical procedures.[1][8]
Where is the scientific evidence strongest?
For pain and medical procedures, where several meta-analyses show medium effects. For irritable bowel syndrome, guidelines recommend gut-directed hypnosis. Results for anxiety are promising, but the studies are small.[1][3][14][19][13]
What do brain scans show during hypnosis?
Imaging studies show that brain activity changes measurably during hypnosis, for example in networks for attention and self-awareness. There is not yet a single pattern that appears in every study.[8][9]
What are the success rates with hypnosis?
That depends heavily on the topic. For IBS, about half of patients reached adequate long-term relief in one meta-analysis; for smoking cessation, around 15% were continuously smoke-free after a year, the same as with CBT. Blanket success rates such as “90%” are not supported by studies.[18][16]
Can everyone be hypnotised?
Almost everyone responds to suggestions, but to different degrees; this is one of the best-established findings in hypnosis research. In standard tests, hypnotizability stays fairly stable over decades, and some effects, such as pain relief, are smaller in people with low suggestibility. These tests, however, measure without practice and with a standardised procedure. In training studies, more than half of initially low-hypnotizable people became clearly more responsive, and rapport with the person guiding them played a role. How much of that is real change and how much is expectation is debated.[24][25][23][26][39][27]
Is hypnosis safe?
Yes. Serious side effects have not been shown in studies; milder ones are rare and usually brief. You stay responsive and can stop at any time. Hypnosis is not suitable during acute psychosis or for severe personality disorders.[30][31][10]
Can hypnosis help you remember something forgotten?
Sometimes, for example a forgotten password. But remembering in trance does not work like looking at a photograph: under suggestion, false memories can also form. Anything that can be checked, like a password, shows immediately whether it is right.[32][11]
More on how I use this research in practice.
See the method