I had a past life regression done by a very reputable hypnotist but it was done in light trance so the conscious mind is still very active, and therefore fantasy could have been involved.
On the other hand, I brought up information I could not have known (I had to google it to find out that I wasn't making this stuff up).
Past life regression is a great way to tap into your subconscious mind as well.
It's risky when you bring up traumatic stuff, and may relive things - things you're subconscious brain was trying to protect you from...doing more damage than good. And then if you have a hypnotist who isn't responsible or only half knows what they're doing, they may not know how to deal with it. A properly train hypnotist will have a safety plan ready, and will know how to bring you out of the "reliving" experience and move you into an objective witnessing experience or totally into a safe place - this is all done during the guided hypnosis. And they will stop the session if it is going into territory they are not professionally trained to deal with - and will refer you to a specialist.
A responsible hypnotist would ask for a doctor's referral before doing this kind of hypnosis with you - and would refuse to do it for certain types of clients. It isn't a good idea for people who have hallucination issues for example. So some contraindications...
But if you train yourself to notice the things you are drawn to in ordinary consciousness... you can already figure out what your past lives were because there are little pieces of them popping up in your present life all the time.
So it's a mixed bag.... not for everybody.
Here is a great site for more information:
http://ngh.net/
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