From angiotensin to cortisol, testosterone to xenoestrogens, and dopamine to endocrine disruptors, hormones are everywhere. These chemical entities are foundational to biological life and shape social, cultural, and political forces, while simultaneously being shaped by them. Hormones are increasingly central not only to medical and other body-shaping practices and contemporary science, but also environmentally-oriented conversations. Throughout Hormonal Theory, authors trace how biomedical, social, political, and experiential forces entangle to produce hormones as we know them today. It illuminates how hormones emerge and exist as complex entities that permeate every sphere of our lives. Each glossary entry takes a particular hormonal compound as its starting point, yet works to elaborate and complicate understandings of hormones as distinct biological or chemical entities. The entries collectively show how hormones never operate in isolation from other hormones, nor bodies in isolation from other human and non-human bodies and their socio-ecological surroundings. Indeed, they “cascade” into one another. This volume, then, is not simply a qualitatively-rich companion to medical knowledge about hormones, but a challenge to the conceptual underpinnings of current dominant understandings of disease, wellness, and normalcy.