The effect of menopausal hormone therapy (MHT), previously known as hormone replacement therapy, on cardiovascular health in post-menopausal women remains controversial and unclear. Extensive observational data had suggested MHT to be cardioprotective [1–3], leading to MHT being routinely prescribed for both primary and secondary prevention of coronary heart disease (CHD). However, subsequent data from the Women’s Health Initiative (WHI) and Heart and Estrogen/Progestin Replacement Study (HERS) studies cast doubt on the beneficial cardiovascular effects of MHT [4–6]; this was reflected in learned societies’ clinical guidance concerning MHT’s role in CHD prevention . The most recent randomised trial data on the subject arose from the Danish Osteoporosis Prevention Study , which indicated that women taking MHT had a reduced risk of the composite endpoint of mortality, heart failure and myocardial infarction but the study has been subject to criticism . In more recent work, again from the WHI, there was no difference in cardiovascular mortality in MHT users compared to placebo, although the authors themselves state that cause-specific mortality data should be interpreted “cautiously” . it has been suggested that commencement of MHT in the perimenopausal transition or early menopause is not associated with increased risk of CHD compared to when treatment is administered at a later stage. This is known as the “timing hypothesis” .