This is the third and final article related to the endocrine system and centres on the female hormones oestrogen and progesterone. Initially the normal cyclic hormonal events of the menstrual cycle are described followed by an account of the use of hormones for hormonal replacement therapy and contraceptive purposes. Campbell and Pickard (2007) report on the National Statistics report of 2005 stating that 62 million prescriptions for combined oral contraceptives and 12 million prescriptions for progesterone only contraceptives were issued. This highlights the enormity of contraceptive use and the likelihood of the healthcare assistants and assistant practitioner encountering this medication.