Pain Relief

Hypnosis Before Surgery: 9,238 Patients, and the Strongest Number in the Field

This year the journal Anaesthesia published the largest synthesis ever attempted on hypnosis around medical procedures: 142 studies, 9,238 patients. People who had hypnosis before their procedure reported less pain and markedly less anxiety, and the risk of post-operative nausea and vomiting came out at less than half. This is the best ground hypnosis has, and it is worth understanding precisely.

The headline, with its edges intact.Lahoud, Gurary and Elia found a relative risk of 0.43 for post-operative nausea and vomiting, 95% confidence interval 0.25 to 0.74. That is the single strongest number anywhere in the hypnosis literature, and it comes from the largest review in it.

The same authors are explicit that their primary outcome — how much hypnotic and opioid medication patients needed — was not demonstrated, and they write that hypnosis’s “impact on most outcomes remains unknown”. Both of those sentences are theirs. A page that gave you one without the other would be selling you something.

Ernest McLeod, clinical hypnotherapist, Adelaide

Written by Ernest McLeodClinical hypnotherapist. An Adelaide practice, seeing clients across Australia by video. Fourteen years in practice. About Ernest →

I earn a commission when someone buys a session through this site. Nothing on this page is a reason to change one thing about your medical care, and I have written it so that you can check every figure yourself.

What does the biggest review of hypnosis before surgery show?

Four outcomes, each measured against the care those patients would otherwise have had, and each pooled across a set of trials large enough that one odd result cannot drive it. Here they are in the order you would meet them.

  1. Pain before the procedure. A mean difference of −0.88 cm on a visual analogue scale, 95% CI −1.72 to −0.05.
  2. Anxiety before the procedure. A standardised effect of −0.76, 95% CI −1.14 to −0.38. In this literature that is a large effect, and anxiety is what most people actually arrive with.
  3. Pain during the procedure. A mean difference of −1.14 cm, 95% CI −1.86 to −0.41.
  4. Post-operative nausea and vomiting. Relative risk 0.43, 95% CI 0.25 to 0.74.

Take the anxiety figure seriously, because it is the one most likely to describe you. Nobody lies awake the night before a procedure worrying about a centimetre on a pain scale. They lie awake worrying. An effect of −0.76 on that, across a review this size, is not a small claim.

Do the earlier reviews agree?

This is not one paper standing on its own, which is the usual problem with hypnosis research. Tefikow and colleagues pooled 34 randomised trials and 2,597 surgical patients in 2013. Emotional distress came out at g = 0.53 (0.37–0.69), pain at 0.44 (0.26–0.61), medication use at 0.38 (0.20–0.56), recovery at 0.25 (0.04–0.46) and procedure time at 0.25 (0.12–0.38). Every one of those intervals sits clear of zero.

Holler and colleagues repeated the exercise in 2021 across 50 studies and 4,269 patients: mental distress g = 0.55 (0.39–0.70), pain g = 0.37 (0.25–0.50). They also translated those into numbers needed to treat — 3.32 for distress and 4.78 for pain — and those two figures get quoted everywhere without the sentence that has to travel with them.

The sentence that has to travel with the NNTs.In Holler’s own words, the 95% prediction intervals included the null effect for all outcomes except for procedure time.

Plainly: the average across those 50 studies was a real benefit, but the spread between studies was wide enough that a new trial, run tomorrow, could plausibly find nothing at all on distress or on pain. An NNT of 3.32 quoted without that is a half-truth, and you will see it quoted that way on a dozen clinic sites.

A third and more recent pooling, Walter and colleagues in 2025, took 20 randomised trials and 1,250 patients and landed in the same territory: anxiety −0.43 (−0.58 to −0.28), pain −0.35 (−0.50 to −0.20). Their note on harms was four words long. “Adverse effects were minimal.”

And when Rosendahl’s team mapped the whole field in 2024 — 49 meta-analyses, 261 distinct primary studies — they concluded that the largest effects were “found in patients experiencing pain, patients undergoing medical procedures, and in populations of children/adolescents”. Worth disclosing: the senior author sits on the scientific board of the Milton H. Erickson Society Germany, and only nine of those 49 meta-analyses rated highly for quality.

Where the evidence runs out

Three limits, and I would rather you had them from me than from a comments section.

The medication question is unresolved. Lahoud’s primary outcome was hypnotic and opioid use, and it was not demonstrated. If you came here hoping to need less of something at the sharp end, the largest review in the field could not show that.

The comparator changes the answer. Scheffler’s 2018 review of hypnosis in burns care is the cleanest demonstration. Across 21 randomised trials and 660 patients the overall effect was g = 0.58. Against treatment as usual it was 0.69 (0.40–0.98). Against an attention control — somebody spending the same time with the patient, doing something other than hypnosis — it was 0.21, with a confidence interval from −0.11 to 0.54, which is to say not significant. The difference between those two comparisons was itself significant at p < 0.001. Some of what these trials measure is attention.

None of these trials used a downloaded recording. The nausea figure, the NNTs, the procedure-time results — all of it was delivered by a clinician, in a hospital, to a specific patient. There is a separate and genuinely encouraging body of work on whether format matters, which I have put on its own page about self-hypnosis and recordings, because it deserves to be argued properly rather than borrowed here. What I will not do is let a 9,238-patient hospital result stand in for something you bought for twenty-seven dollars.

When should you start, and how many times?

This is the practical part, and it is unusually clear. Kendrick and colleagues, reviewing this literature in 2016, found that the best results came from more than one session, delivered before the day of the procedure — not a single induction in the waiting bay with a cannula already in your hand.

So if you are going to try this, the useful version is: start a fortnight out, practise on ordinary days when nothing is happening, and arrive at the hospital already familiar with it. That is a thing you can act on, it costs nothing to act on, and it is the opposite of what most people do.

Tell your anaesthetist and your surgical team.Not because hypnosis is risky — the recorded harms are very small — but because they are running your care and they should know what you are doing. Say that you are listening to a relaxation or hypnosis recording before the day, and ask whether they would like you to do anything differently.

Change nothing else. Not your fasting instructions, not your pre-medication, not a prescription, not the time you are due. Nothing on this page is a reason to alter any part of your treatment, and no recording is an alternative to anaesthesia or analgesia.

Is it safe?

Bollinger went through the adverse events recorded in hypnosis clinical trials in 2018 and found serious adverse events attributable to hypnosis at zero per cent, with other adverse events at 0.47 per cent. The honest reading is “none were reported in registered trials”, not “proven harmless”. The author names his own limitation: those trials were treating medical conditions and procedures rather than psychiatric ones. For a page about surgery, that is exactly the population it covers.

The everyday cautions still apply. Never listen while driving or anywhere else that needs your attention, and never stop a prescribed medication without your doctor’s approval.

Which sessions on this site come closest?

There are seventeen pain-relief sessions on this site, each US$18.95, about A$27, with ninety days to change your mind. None of them is a surgical protocol and none was used in any trial above. The two closest to what this page describes are Fear of Pain, for the dread that arrives before the procedure does, and Pain Relief, the general one. If your procedure is urological, there is also Ease Male Post Catheter Pain. The full seventeen sit under pain relief.

What you are buying is a rehearsal: twenty-odd fixed minutes of guided attention, practised in the fortnight before, in a format the surgical trials did not test. That is a modest and honest description, and it is the one I will stand behind.

Common questions

Does hypnosis before surgery actually work?

It has better evidence here than anywhere else. A 2026 review in Anaesthesia pooled 142 studies and 9,238 patients and found less pain before and during procedures, a large reduction in pre-procedure anxiety, and post-operative nausea and vomiting at a relative risk of 0.43. The same authors could not demonstrate their primary outcome, medication use, and say hypnosis’s impact on most outcomes remains unknown.

How far before my operation should I start?

Earlier than most people assume. Kendrick and colleagues found in 2016 that multiple sessions delivered before the day of the procedure worked best, rather than a single induction on the day itself. Practically that means starting a week or two out and practising on ordinary days, so the recording is familiar before you are anxious.

Should I tell my anaesthetist?

Yes. They are running your care and should know what you are doing, even though recorded harms from hypnosis are very small. Mention it at your pre-admission appointment. And change nothing else: not your fasting instructions, not your pre-medication, not a prescription, and not on the strength of anything written here.

Will it mean I need less pain medication?

That is precisely what the largest review could not show. Medication use was Lahoud’s primary outcome in 2026 and it was not demonstrated. An earlier review, Tefikow 2013 across 34 randomised trials, did find a small effect on medication of g = 0.38. Treat it as unresolved, and never plan around needing less of anything.

What is the catch with the numbers needed to treat?

Holler’s 2021 review reported an NNT of 3.32 for mental distress and 4.78 for pain across 50 studies. Those are widely quoted without the authors’ own caveat: the 95% prediction intervals included the null effect for every outcome except procedure time. The average benefit was real; the spread between studies was wide enough that a fresh trial could find nothing.

Do the hospital results apply to a recording I download?

Not directly. Every trial behind the nausea figure and the surgical NNTs used a clinician working with a patient in person. There is separate evidence that delivery format may matter less than expected — Yim and Derbyshire’s 2026 subgroup analysis found no significant difference between self-hypnosis, taped and therapist-delivered hypnosis for pain, p = 0.94 — but that is a different body of work with smaller subgroups.

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Where these numbers come from

  • Lahoud MJ, Gurary ST, Elia N. Hypnosis for anaesthetists: a systematic review and meta-analyses. Anaesthesia. 2026;81(1):103-15. doi:10.1111/anae.70013
  • Tefikow S, Barth J, Maichrowitz S, et al. Efficacy of hypnosis in adults undergoing surgery or medical procedures: a meta-analysis of randomized controlled trials. Clin Psychol Rev. 2013;33(5):623-36. doi:10.1016/j.cpr.2013.03.005
  • Holler M, Koranyi S, Strauss B, et al. Efficacy of hypnosis in adults undergoing surgical procedures: a meta-analytic update. Clin Psychol Rev. 2021;85:102001. doi:10.1016/j.cpr.2021.102001
  • Walter N, Leyva MT, Hinterberger T, et al. Hypnosis as a non-pharmacological intervention for invasive medical procedures – a systematic review and meta-analytic update. J Psychosom Res. 2025;192:112117. doi:10.1016/j.jpsychores.2025.112117
  • Rosendahl J, Alldredge CT, Haddenhorst A. Meta-analytic evidence on the efficacy of hypnosis for mental and somatic health issues: a 20-year perspective. Front Psychol. 2024;14:1330238. doi:10.3389/fpsyg.2023.1330238
  • Scheffler M, Koranyi S, Meissner W, et al. Efficacy of non-pharmacological interventions for procedural pain relief in adults undergoing burn wound care: a systematic review and meta-analysis of randomized controlled trials. Burns. 2018;44(7):1709-20. doi:10.1016/j.burns.2017.11.019
  • Kendrick C, Sliwinski J, Yu Y, et al. Hypnosis for acute procedural pain: a critical review. Int J Clin Exp Hypn. 2016;64(1):75-115. doi:10.1080/00207144.2015.1099405
  • Bollinger JW. The rate of adverse events related to hypnosis during clinical trials. Am J Clin Hypn. 2018;60(4):357-66. doi:10.1080/00029157.2017.1315927
  • Yim TH, Derbyshire SWG. A systematic review of hypnosis for clinical pain relief. Eur J Pain. 2026;30(8):e70369. doi:10.1002/ejp.70369
  • Better Health Channel. Hypnosis [Internet]. Melbourne: Victorian Government, Department of Health; [cited 2026 Sep 24]. betterhealth.vic.gov.au

Related

If you take one thing from this page, take the practical one: start before the day, practise more than once, and tell the team looking after you.

The three sessions on this page

Every one is an instant MP3 from the publisher at US$18.95, about A$27, with ninety days to change your mind. I earn a commission; it changes neither what you pay nor what I list.

  • Prepare for Surgery

    US$18.95 · instant MP3 · ninety-day refund

    The one built for the weeks before an operation. Rehearsal, not sedation.

  • Fear of General Anesthesia

    US$18.95 · instant MP3 · ninety-day refund

    For when the fear is specifically of going under.

  • Overcome Fear of Hospitals

    US$18.95 · instant MP3 · ninety-day refund

    For when the building itself is the problem, before any procedure is booked.

These are self-help audio sessions, not medical treatment, a diagnosis, or a substitute for professional care. No therapeutic outcome is claimed for any session sold on this site, and none of the trials described here used a purchased recording. Nothing here is a reason to change any part of your medical care: follow your surgical and anaesthetic team’s instructions exactly, and do not stop prescribed medication without your doctor’s approval. Chronic pain should be investigated by a doctor before it is managed with anything. Better Health Channel advises avoiding hypnosis with severe depression, psychosis, or a drug or alcohol problem. Never listen while driving or operating machinery.

Written by Ernest McLeod — clinical hypnotherapist, Adelaide, seeing clients Australia-wide by video. Last updated 2026-09-24.