Hormone replacement therapy is the treatment used to replace hormones post-menopause in order to relieve symptoms such as hot flushes, vaginal dryness, and mood swings. It can also relieve atrophy of the vagina, relieve perimenopausal bleeding and prevent osteoporosis. However, hormone replacement therapy may not be a suitable option if women have a history of ovarian or breast cancer, untreated hypertension, cardiovascular disease, and liver disorders. Oestrogen and progestogen are the two main hormones used in hormone replacement therapy. Oestrogen used in the therapy is further divided into estradiol, estriol, and estrone. The progesterone used in hormone replacement therapy is the synthetic version of progesterone hormone. These two hormones can be taken together as a combined therapy, or by taking oestrogen alone. They are available in the form of tablets, transcutaneous patches, subdermal implants, and transvaginal cream. Side effects of hormone replacement therapy include breast tenderness, bloating, leg cramps and feeling sick.