Kathryn Retzler, ND

Kathryn Retzler, ND is the founder of HormoneSynergy® Longevity Medicine in Portland and Lake Oswego, Oregon. With 25 years of clinical experience, Dr. Retzler focuses on preventive, systems-based medicine that helps patients understand and improve the physiology that drives healthy aging. Her advanced training includes a fellowship in preventive cardiology, which informs her work in cardiovascular risk assessment, metabolic health, hormone balance and cognitive health. Dr. Retzler emphasizes Medicine, Not Marketing—a commitment to evidence-informed care, clinical judgment, and avoiding hype-driven wellness trends. In addition to clinical practice, Dr. Retzler has lectured at age management conferences for years and has taught an all-day couse on Women and Longevity. Her third book "Weight Loss for Longevity" will be coming out in 2026.