The Women's Health Initiative study has found older women without menopausal symptoms taking combined hormone replacement therapy are at a greater risk of breast cancer and cardiovascular disease.
The United States' National Institute of Health has announced it will discontinue the study because of the risk to those taking part.
The Ministry of Health's Dr Bob Boyd said women without menopausal symptoms were not usually prescribed HRT in New Zealand. Those who have concerns should see their doctor.
About 60,000 New Zealand women are using some form of HRT and about 11,000 take a combined HRT.
