Women will be able to take hormone replacement pills without worrying that the therapy will shorten their lifespans, according to the longest follow-up yet of research that raised fears about the risks of a once-popular treatment.

That earlier research was stopped early when unexpected harm was found to be caused by the use of hormone replacement therapy (HRT) – oestrogen alone or in combination with progestin, a synthetic hormone.

More cases of breast cancer, heart attack and stroke occurred in women on combined pills, and those on oestrogen pills had more strokes.

But about 18 years of follow-up research has shown that, despite those risks, women on HRT had similar rates of deaths from breast cancer, heart disease and all other causes as those who took placebos.

The results are reassuring and support current advice: hormones may be appropriate for some women when used short-term to relieve hot flushes and other menopause symptoms, said Dr JoAnn Manson, preventive medicine chief at Boston’s Brigham and Women’s hospital and lead author of the follow-up report.

“It’s the ultimate bottom line,” said Manson, who was also part of the original research. “Women want to know – is this medication going to kill me? And the answer appears to be no.”

Results were published on Tuesday in the Journal of the American Medical Association.

Hormones were once considered a panacea for women entering menopause because of evidence suggesting a host of purported benefits including the reduction of heart disease and the boosting of memory.

The landmark research, backed by the US government, began in the early 1990s to rigorously test hormones’ effects in older women randomly assigned to take the pills or placebos.

The results led to advice against taking hormones to prevent age-related diseases. When used for menopause symptoms, the lowest possible dose for the shortest possible time was recommended, then as now.

For some women already facing health risks, HRT’s potential harms may outweigh any benefits, and discussions with a doctor about starting the treatment are advised.

The follow-up research involved most of the more than 27,000 women who were part of the original research. Some earlier follow-ups suggested no increased risk of death in hormone users, but Manson said this is the first to focus only on deaths from various causes.

Overall, almost 7,500 women died – about 27% each in the hormone and dummy pill groups. Most deaths occurred after women stopped taking hormones. About 9% of women in both groups died from heart disease and about 8% from breast and other cancers.

Among the youngest women, there were fewer overall deaths early on among hormone users than dummy-pill users, but the rates evened out after women stopped using the pills.

Overall, death rates were similar among women on both types of hormone treatment versus dummy pills.

Even so, many women and their doctors remain wary of hormone use. The authors of the follow-up study hope the results “alleviate concerns” about the long-term consequences.

More research is needed on the risks and benefits of other types of hormones, including patches, Manson said.