Hormone Zenshi (Aroused: The History of Hormones and How They Control Just About Everything)

The fundamental force that governs our bodies is an astonishingly tiny substance: hormones. These microscopic chemical messengers orchestrate nearly every aspect of life—growth, emotions, sexual differentiation, sleep cycles, and even appetite. They are the invisible conductors of the symphony that sustains us.
 
This book is the complete translation of Aroused: The History of Hormones and How They Control Just About Everything by physician and writer Randi Hutter Epstein. It explores the fascinating world of hormones, from their discovery to their profound influence on human biology.
 
Hormones are produced not only by major endocrine organs such as the pituitary gland, thyroid, adrenal glands, and gonads, but also by tissues scattered throughout the body—stomach, kidneys, and even fat cells. Scientists have identified more than a hundred distinct hormones, each performing vital tasks. What is truly mind-boggling is the quantity in which they operate: unimaginably small. Picture this—just a spoonful of hormone, measured in picograms per milliliter, dissolved in an Olympic-sized swimming pool, can trigger essential processes that keep us alive. At these minuscule concentrations, hormones regulate blood pressure, red blood cell production, fat storage, appetite, and countless other functions, acting as the keys to life’s delicate balance.
 
What makes this system extraordinary is its precision. Hormone levels are maintained within an incredibly narrow range. A slight excess or deficiency can disrupt the body’s equilibrium, leading to disorders such as diabetes and other endocrine diseases. Insulin, for example, lowers blood sugar, and any malfunction in its secretion can shatter this fragile harmony. In essence, hormones form a high-performance, automatic control system that keeps our bodies running smoothly.
 
The heart of this book lies in its vivid portrayal of the human drama behind scientific breakthroughs. It recounts the fierce debates and social upheaval sparked by the discovery of hormones in the digestive tract. It follows the thrilling journey from a collection of brain specimens to the revelation of the pituitary gland’s role. It tells of a researcher’s relentless quest to extract growth hormone from cadavers for his son’s sake, and of the pioneering couple who laid the foundation for infertility treatments—stories intertwined with unexpected links to transgender medicine. These narratives reveal the desires, ambitions, and conflicts that propelled science forward.
 
With wit and clarity, Epstein guides readers from the basic principles of hormonal regulation to cutting-edge discoveries. The book is far more accessible than a technical textbook, brimming with captivating episodes that require no prior knowledge. By the final page, you will marvel at the intricate hormonal network that governs your body and gain a profound respect for the miracle of life itself.
 
Discover the astonishing world of hormones—the unseen architects of existence—within these pages.
 

(Written by TSUBOI Takashi, Professor, Graduate School of Arts and Sciences / 2025)