Hypnosis can help reduce the prevalence of hot flashes among postmenopausal women by as much as 75%, a new study has found.

Researchers with Baylor University, Indiana University and the University of Texas explored the use of hypnosis to treat hot flashes in a study published online by Menopause, the journal of the North American Menopause Society.

In the study, the women who were treated with hypnosis had five sessions each week during which they were given suggestions for mental images of coolness, a safe place or relaxation, depending on their preference. They also received an audio recording of a hypnotic induction and were asked to practice it each day. The women in the control group met with a clinician five times a week to talk about their symptoms. They, too, received an audio recording they were asked to listen to daily, but it was made up of information about hot flashes.

All of the women kept diaries tracking the frequency and severity of their hot flashes, and their hot flash frequency was measured by a skin conductance monitor.

After 12 weeks, the women who underwent hypnosis reported 75% fewer hot flashes, compared with 13% fewer hot flashes among the women in the control group. The skin conductance readings showed a 57% reduction in hot flashes for women in the hypnosis group and just 10% for those in the control group. The women who underwent hypnosis also reported less interference in their lives from hot flashes and better sleep than those in the control group.

Exactly how hypnosis helps with hot flashes is not clear, the researchers say.