That is a great question, but there is an equally important one for you to answer first. Do you really, really want to stop smoking?
If the answer is yes then the success rates for doing so with hypnosis are very encouraging.
Individual therapists don’t give out numbers because they can be deemed to be misleading. It is not a case of being “cagey” as they can only work with the specific feedback that they have received and not everyone gives it. The only real way is to validate success rates is with a scientific study. Some independent, studies place it around the 90% mark and there is plenty of independent, reputable, information on Google.
Once you have decided that you really do want to quit smoking, chat with a professional hypnotherapist. They will usually be pleased to meet with you to answer any questions.
Find a hypnotherapist that you feel comfortable working with. Someone who will give you proper advice on how to prepare yourself, what is going to happen during the therapy and what your realistic expectations should be.