Adrenaline is a hormone released from the adrenal glands and its major action, together with noradrenaline, is to prepare the body for 'fight or flight'.

Adrenocorticotropic hormone (ACTH) is produced by the pituitary gland. Its key function is to stimulate the production and release of cortisol from the cortex (outer part) of the adrenal gland.

Anti-diuretic hormone acts to maintain blood pressure, blood volume and tissue water content by controlling the amount of water and hence the concentration of urine excreted by the kidney.

Anti-Müllerian hormone is a protein hormone which is important in the development of the reproductive tract in a male foetus and is also produced (before birth) by the testes and ovaries.

Cortisol is a steroid hormone that regulates a wide range of processes throughout the body, including metabolism and the immune response. It also has a very important role in helping the body respond to stress.

Erythropoietin is a hormone, produced mainly in the kidneys, which stimulates the production and maintenance of red blood cells.

Follicle stimulating hormone is produced by the pituitary gland. It regulates the functions of both the ovaries and testes. Lack or low levels of it can cause subfertility in both men and women.

Gastrin is a hormone produced by the stomach, which stimulates gastric motility and the release of gastric acid.

Ghrelin is produced by the stomach. Among its numerous functions, ghrelin increases appetite and stimulates the release of growth hormone.

Glucagon is produced to maintain glucose levels in the bloodstream when fasting and to raise very low glucose levels.

Gonadotrophin-releasing hormone is released from the hypothalamus in the brain. It controls the production of luteinising hormone and follicle stimulating hormone from the pituitary gland.

Human chorionic gonadotrophin is a reproductive hormone that is essential for establishing and maintaining early pregnancy.

Insulin is an essential hormone produced by the pancreas. Its main role is to control glucose levels in our bodies.

Kisspeptin is a protein that is essential for reproductive hormone secretion and fertility. The gene (which provides the blue-print for the kisspeptin protein) was first discovered in 1996 by a group of researchers working in Hershey, Pennsylvania in the USA. It is therefore named after the city's chocolate 'Kisses', which are made in Hershey.

Luteinising hormone is produced by the pituitary gland and is one of the main hormones that control the reproductive system.

Melatonin is mainly produced by the pineal gland and although it appears not to be essential for human physiology, it is known to have a range of different effects when taken as a medication.

Oestradiol is an important reproductive hormone that has a wide range of actions in both men and women.

Oestriol is a hormone made during pregnancy that can be used to measure foetal health and predict when birth may happen.

Oestrone is a hormone produced by the ovaries, adrenal glands and fat. It is one of the major oestrogens in postmenopausal women.

Oxytocin is a hormone that acts on organs in the body (including the breast and uterus) and as a chemical messenger in the brain controlling key aspects of the female reproductive system including childbirth and lactation.

Peptide YY is a hormone made in the small intestine. It helps to reduce appetite and limit food intake.

Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy.

Prolactin is a hormone produced in the pituitary gland, named because of its role in lactation. It also has other wide-ranging functions in the body, from acting on the reproductive system to influencing behaviour and regulating the immune system.

The prostaglandins are a group of lipids (fats) made at sites of tissue damage or infection that have actions similar to hormones and are involved in dealing with injury and illness. They control processes such as inflammation, blood flow, the formation of blood clots and the induction of labour.

Relaxin is a hormone produced by the ovary and the placenta with important effects in the female reproductive system and during pregnancy. In preparation for childbirth, it relaxes the ligaments in the pelvis and softens and widens the cervix.

Testosterone is a hormone that is responsible for many of the physical characteristics specific to adult males. It plays a key role in reproduction and the maintenance of bone and muscle strength.

Thyroid Stimulating Hormone (TSH) is produced by the pituitary gland. Its role is to regulate (by stimulating) the production of thyroid hormones by the thyroid gland.