The Virility Paradox: The Vast Influence of Testosterone on Our Bodies, Minds, and the World We Live in

From mandatory testing for military personnel to the prevalence of “Low T” clinics, testosterone keeps showing up in headlines, but the profound effects this hormone has on our lives are nothing new.

A scientific exploration of men's health, TRT, and human behavior, The Virility Paradox reveals the vast and often unexpected influence this powerful hormone has on our minds, our relationships, and our society.

The brain of every man—and every woman—is shaped by this tiny molecule before birth. It fuels our drive for exploration, risk-taking, competition, creativity, and survival. The effects of testosterone permeate the traditions, philosophy, and literature of every known culture. Without it, the world would be drastically different.

Testosterone also plays a role in humanity's darker side, contributing to violence, hubris, poverty, crime, and selfishness. Its effects can reduce compassion, generosity, and even the affection we show our children, shedding light on long-held assumptions about masculinity and male psychology.

In The Virility Paradox, internationally renowned oncologist and prostate cancer researcher Charles Ryan explores the remarkably complex biological system responsible for a diverse spectrum of human behaviors and health outcomes in both men and women. Over decades of treating patients with hormone depleting treatments, Ryan observed profound and diverse changes in many individual’s perspectives on their lives, relationships, and emotional well-being.

Drawing on neuroscience, evolutionary biology, and stories of real men and women, Ryan explores:

• The link between testosterone and conditions like dementia, autism, and cancer
• Surprising outcomes of using hormone replacement therapy and what these treatments reveal about the brain
• How hormone biology influences every choice we make, from crime and investing to parenting and relationships
• The significant role hormones play in an individual’s anxiety, mental health, fatigue, libido, longevity, and more
• The biological underpinnings of sexual assault

Integrating the molecular and the medical, sociology and storytelling, The Virility Paradox offers a fascinating look at how one hormone has shaped history, and the connections between our biology, our behavior, and our best selves.

Charles J Ryan, MD, is The Thomas Perkins Distinguished Professor of Clinical Medicine and Urology at the Helen Diller Family Comprehensive Cancer Center at the University of California, San Francisco (UCSF). Dr. Ryan earned a BA in Philosophy, magna cum laude from Marquette University where he was inducted into Phi Beta Kappa. He attended the University of Wisconsin Medical School. He trained at the University of Wisconsin Hospital and at Memorial Sloan-Kettering Cancer Center in New York. He is the Program Leader for genitourinary medical oncology at UCSF and is Chair of the UCSF Committee on Human Research, which oversees the ethical conduct of research on humans at the institution. He serves as co-chair of the National Cancer Institute’s Prostate Cancer Task Force and the leader of the Advanced Prostate Cancer Cadre in the Alliance for Clinical Trials in Oncology, a national clinical trials group.

Dr. Ryan’s research focuses on the development of new treatments for advanced prostate cancer and he has published over 100 articles and chapters in the world’s leading medical journals including the New England Journal of Medicine. In addition, he was the principal investigator for the development of Abiraterone acetate, a treatment now considered a standard of care in advanced prostate cancer. It has been administered to over 200,000 patients worldwide. Dr. Ryan is the cofounder of the Supportive Therapy in Androgen Deprivation (STAND) program at UCSF, a program which seeks to integrate physical activity, nutrition, and emotional support for men receiving hormonal therapy for prostate cancer and their partners.