Hormone replacement therapy (HRT) is now a discredited drug - but it took years before researchers finally released all their damning evidence. When it came out, Prof Bruno Muller-Oerlinghausen, chairman of the German Commission on the Safety of Medicines, described it as a 'national and international tragedy', and he likened it to the thalidomide scandal. Reports suggest that it has already killed thousands of women who just wanted a better menopause.
It has been estimated that HRT has caused 20,000 cases of breast cancer in Britain alone, and is known to double the risk of breast cancer, and increase the risk of blood clots, strokes and heart attack.
The bubble started to burst in 2002 when the Women's Health Initiative trial was stopped prematurely after it was discovered that oestrogen plus progestin increased the risk of stroke in post-menopausal women.
This alarming discovery overshadowed another finding from the same trial - published a year later - that found the therapy also increases the risk of dementia among women aged over 65.
In fact, the risk is more than doubled in women who take one HRT tablet a day compared with those taking a placebo.
The risk was discovered after tracking over a four-year period the progress of 4,532 women who were older than 65 and had good mental health at the start of the study. Half were given HRT therapy and the rest had a placebo.
Overall, 61 women were diagnosed with dementia, 40 of whom were in the HRT group and 21 in the placebo group.
Researchers estimate that HRT will create an additional 23 cases of dementia a year for every 10,000 women taking the drug.
The risk of dementia, coupled with the increased risk of stroke, means that the risks of HRT outweigh any benefits, the study concludes.