About Louise
Dr. Louise Greenspan is a highly respected pediatric endocrinologist—a doctor who specializes in children’s hormones—and a Clinical Professor at the University of California San Francisco (UCSF), while also practicing at Kaiser Permanente. For over two decades, her research has focused on the critical and sometimes alarming trend of girls starting puberty earlier than in generations past. She was a lead investigator in one of North America’s largest and longest studies, tracking thousands of young girls to understand what is causing this shift. Her research, often called the Trio Study, found that everyday environmental factors, such as certain chemicals (like phthalates) found in plastics and consumer products, along with increasing childhood weight, significantly affect the timing of hormone release and development. This groundbreaking work proved that external exposures play a much bigger role in early puberty than previously believed. To translate these critical scientific findings for families, Louise co-authored the well-known book, The New Puberty: How to Navigate Early Development in Today’s Girls, with Dr. Julianna Deardorff. Because she is comfortable and open about discussing complex and often “taboo” topics like body changes and hormone disruption, she is a trusted source for parents. Her goal is to empower families to understand the new science and help their daughters navigate these rapid and complex changes confidently and without shame.
