“What is The Million Women Study? The Million Women Study is a national study of women’s health, involving more than one million UK women aged 50 and over. It is a collaborative project between Cancer Research UK and the National Health Service, with additional funding from the Medical Research Council and the Health and Safety Executive, which aims to answer many outstanding questions about the factors affecting women’s health in this age group. The main focus of the study relates to the effects of hormone replacement therapy use, but the large size of the study means that a very broad range of health issues can be addressed.”