Acupuncture and hypnosis can be effective in helping some smokers quit, according to a review of 14 studies. These approaches may be useful for smokers who can’t stop smoking using standard approaches such as nicotine replacement therapy, medications and behavioral counseling, Reuters reports.

The researchers say they still do not know exactly how effective acupuncture and hypnosis are as smoking cessation aids, and how they compare with conventional treatments.

Some studies included in the review found that smokers who used acupuncture were more than three times as likely to be smoke free after six months to one year. Smokers who underwent hypnosis were also more successful at quitting smoking compared with those who received minimal assistance, according to the article.

The success rate of the treatments was not consistent in all of the studies reviewed. Lead researcher Mehdi Tahiri of McGill University in Montreal noted it is still not known how many sessions of acupuncture or hypnosis are needed to help smokers quit, or which specific techniques are most effective.

The findings appear in the American Journal of Medicine.