Nicotine patches are no better than willpower alone in helping smokers quit their habit, a study has found.

Gums and nasal sprays are equally ineffective, according to research in the US by the Harvard University School of Public Health.

Surveys of 787 smokers attempting to give up showed a third relapsed whether using nicotine replacement products or not.

Heavy smokers who used patches or similar treatments but did not also seek therapy were twice as likely to relapse as those who did not use patches.

The study, published in the journal Tobacco Control, questioned subjects three times over five years. The report said that the findings "may indicate that some heavily dependent smokers perceive NRT as a 'magic' pill and, realising it is not, they find themselves without support in their quitting efforts and doomed to failure".