Hormone replacement therapy. View of a skin patch on skin. This transdermal skin patch is used for hormone replacement therapy (HRT). The patch slowly administers the hormone oestrogen into the bloodstream. Oestrogen replacement therapy is typically given to relieve menopausal symptoms in women. These symptoms can include hot flushes, night sweating and atrophic vaginitis (vaginal dryness). HRT also helps prevent atherosclerosis (arterial narrowing due to fatty deposits) and osteoporosis (loss of bone density). Treatment is normally given for two to five years.