Estrogens after menopause – 10 years may be not enough Martin Birkhaeuser, Prof. emeritus for Gynaecological Endocrinology and Reproductive Medicine, University of Berne, Switzerland MHT is the most effective therapy for vasomotor symptoms and urogenital atrophy. Other menopause-related complaints, such as joint and muscle pains, mood swings, sleep disturbances, sexual dysfunction (including reduced libido) and quality of life may improve during MHT. Although median total VMS duration is 7 years, about 25% of all women suffer at the age of 65 years still from hot flushes. VMS may last far into the ages of 80-90 years. Furthermore, MHT has been shown to significantly lower the risk of hip, vertebral and other osteoporosis-related fractures in post-menopausal women independent of age. There are no reasons to place mandatory limitations on the duration of oestrogen administration if MHT is individualized and tailored according to symptoms and the need for prevention, as well as personal and family history, results of relevant investigations and the woman’s preferences and expectations. In a recent study, among a group of women aged 85 years, about 16% experienced still vasomotor symptoms, almost 10% were very to moderately distressed by their hot flushes and 6.5% were currently using MHT. For the continuation of MHT after the age of 65, a documented indication such as persistent climacteric symptoms or bone loss is needed, with shared decision making and periodic re-evaluation. If systemic MHT is needed, low-dose and ultralow-dose oestrogens are sufficient in most elderly women for a significant amelioration of climacteric symptoms, allowing to maintain the benefits and to lower the risks. Transdermal administration should be chosen to minimize the risks of VTE and stroke. Although the evidence is small, it can be assumed that, in elderly healthy symptomatic women without MHT-specific risk factors in whom MHT has been started below the age of 60 years or within 10 years of menopause onset and then continued into the old age, benefits will outweigh the risks. This is not the case if MHT has been initiated only after this “window of opportunity”.