ὁρμῶν

Hormōn is the present participle of Greek horman (to set in motion, to urge on, to stimulate). The word was coined in 1905 by the British physiologist Ernest Starling during a lecture at the Royal College of Physicians in London. Starling and his colleague William Bayliss had discovered secretin — a substance produced by the small intestine that stimulates the pancreas to release digestive enzymes. They needed a word for substances produced in one organ that affect another. Starling chose the Greek word for 'setting in motion.'

The concept of chemical messengers in the body was new. Before Starling, the body was thought to be controlled entirely by the nervous system — electrical signals through nerves. The discovery that chemical signals could travel through the blood and affect distant organs opened an entirely new field: endocrinology. The word 'hormone' named not just a substance but a mechanism.

The sex hormones — testosterone, estrogen, progesterone — became the most culturally visible hormones in the twentieth century. 'Hormonal' entered everyday language as an explanation for mood, behavior, and physical change. 'It's hormonal' became a catch-all explanation for adolescent behavior, premenstrual symptoms, menopausal changes, and emotional volatility. The scientific term became a cultural shorthand, often used imprecisely.

The human body produces over fifty different hormones, regulating everything from growth to mood to hunger to sleep. Insulin (pancreas), cortisol (adrenal), melatonin (pineal), oxytocin (hypothalamus) — each is a hormone with a specific function. The word Starling coined in 1905 now names the chemical language the body uses to talk to itself.