Hypnosis in halachah

Hi,

Hypnotism works through natural means on the body's nervous system; therefore, it is not considered any form of "magic", and one may practice it. Whether it works for particular purposes is another matter.

(Rav Moshe Feinstein, Igrot Moshe Yoreh Deah 2:29 [end])

Have a great day,
Mordechai