I found this study, it suggests outcome is related to susceptibility to hypnosis, have you ever been hypnotized before? What was the outcome?
https://www.sciencedirect.com/science/article/abs/pii/S0149763418304913
1963
This a book from 1994
https://www.taylorfrancis.com/books/mono/10.4324/9780203765647/hypnosis-relief-pain-ernest-hilgard-josephine-hilgard
I think this is a book. They found hypnosis worked

https://www.taylorfrancis.com/chapters/edit/10.4324/9781003596806-22/unlocking-relief%E2%80%94the-power-hypnosis-pain-management-%E2%80%94an-explorative-study-saket-rai 2025
“ his technique involves inducing a focused and suggestible state in individuals, enabling them to alter their perception of pain and discomfort. It has proven effective for various types of pain, including acute pain from surgery or injuries, chronic pain like arthritis or cancer-related pain, neuropathic pain from nerve damage, and psychological pain tied to anxiety or depression. Critical advantages of Hypnosis in pain management include its non-invasive nature, free from adverse side effects
https://www.taylorfrancis.com/books/mono/10.4324/9780203765647/hypnosis-relief-pain-ernest-hilgard-josephine-hilgard
The data suggest that “the hypnotic trance state” may be an extraneous variable in ameliorating pain experience in situations described as “hypnosis;” the critical variables appear to include: (a) suggestions of pain relief, which are (b) given in a close interpersonal setting.

Here’s a newer one, a meta analysis
https://journals.lww.com/painrpts/fulltext/2024/10000/adjunctive_use_of_hypnosis_for_clinical_pain__a.9.aspx
“ Seventy studies were pooled in meta-analyses (n = 6078). Hypnosis adjunctive to usual care had a small additional analgesic effect (chronic pain: −8.2 [−11.8, −1.9]; medical procedures/surgical pain: −6.9 [−10.4, −3.3]; burn wound care: −8.8 [−13.8, −3.9]).
Nem

I had hypnosis 12 times to help me stop smoking. My opinion was that I wasn’t hypnotized. When I said this to the practitioner he responded “yes you were”. I didn’t stop smoking or even cut back a little. I suspect outcome relies in part on the skill of the hypnotist and either the willingness or susceptibility of the patient.