About one in eight women experience hot flushes and night sweats during menopause and researchers estimate they last  over a period averaging between five and seven years, prompting many to seek treatment.

Researchers from a range of universities partnered with Jean Hailes for Women's Health to find 327 women with hot flushes during menopause. They wanted to see if eight weeks of acupuncture or a sham treatment designed to feel like acupuncture helped.

The women were split into two groups to receive 10 sessions of either acupuncture or the sham treatment delivered by experienced acupuncturists. The women did not know which group they were in.

Baseline scores measuring the severity and frequency of their hot flushes were completed at the beginning and end of the study. At the end, the average score was about 40 per cent lower in both groups, suggesting an improvement. However, this also showed that real acupuncture produced similar results to a sham needle that telescopes into itself, giving the visual and physical impression of insertion into the skin.

The researchers concluded that unless further high-quality evidence emerges, they cannot recommend acupuncture for menopausal hot flushes. The study was published in the Annals of Internal Medicine today.

Lead author of the study Carolyn Ee said it was difficult to know what was leading to the improved scores at the end of the trial, which persisted when participants were surveyed again six months after the study was completed. Dr Ee, a GP and Chinese medicine practitioner with Melbourne University, said it was possible that the placebo effect was at play and that women were not reporting flushes during the study because they believed they were being treated.

"We also think that people might enrol in these studies when they're at the height of their symptoms and you naturally see a decline in their symptoms following that, so they may have just got better without treatment," she said.

While the study is likely to disappoint women who pay for acupuncture to treat menopausal symptoms (about 50 per cent of women are believed to have tried it), Dr Ee said they should be reassured that hot flushes do not last forever.

"It does get better over time. We do hear of women who have them for 20 years but that is the exception, not the norm," she said.

Research has shown that hormone replacement therapy is an effective treatment for some menopausal symptoms, however, some women are reluctant to use it because it can slightly increase their risk of cancer.

Martha Hickey, Professor of Obstetrics and Gynaecology at the University of Melbourne and Royal Women's Hospital,  said the acupuncture study was very useful for women investigating treatments for hot flushes. She said women should get individualised advice about HRT from their doctors before judging the benefits and risks. Other non-hormonal treatments available for hot flushes during menopause include several antidepressants, an anti-convulsant drug called Gabapentin and a blood pressure drug called Clonidine.

Dr Adeline Ooi, a GP at the Jean Hailes for Women's Health clinic who practices acupuncture for musculoskeletal conditions, said she would still discuss acupuncture with women who have exhausted other treatments. She said being proactive and having a therapist listen to you and attend to you, could still be helpful.

"I think to offer a woman who is suffering nothing is unhelpful. I'd rather offer them an optional intervention instead of nothing at all."