It is used to mimic the activity of the naturally occurring female sex hormones oestrogen and progestogen in the body. It helps to restore the natural balance of these hormones. It is a female sex hormone, sometimes known as a hormone replacement therapy (HRT). It is used to relieve symptoms that start to occur when the female body no longer produces certain hormones such as oestrogen. This may occur after the menopause, also known as the change of life, or after surgery to remove the ovaries. Tibolone may also be used to stop your bones from becoming brittle.