In this episode of Optispan, longevity scientist Dr. Matt Kaeberlein shares his personal journey with testosterone therapy. Known for his decades of research on aging, Kaeberlein turns the spotlight inward to explore how testosterone affected his body, mind, and health—and what he learned from the experience.

Key Points:

Dr. Matt Kaeberlein offers a personal account of his decision to start testosterone therapy after turning 50. He highlights both the physiological impacts and the broader implications for longevity science. His story is a case study in data-driven self-experimentation, informed by decades of research and personal insight.

•  Why He Tried Testosterone: Despite past skepticism, Kaeberlein began testosterone replacement therapy (TRT) after noticing age-related decline in energy, mood, and physical performance, and finding his levels were below clinical norms.
• Physiological Changes and Monitoring: He saw rapid changes—improved muscle mass, energy, and libido—while carefully tracking biomarkers and adjusting doses based on bloodwork and side effects.
• Mistakes and Adjustments: Early missteps included over-supplementation and underestimating how sensitive hormonal balance is. He cautions against casual or unmonitored use.
• Mood, Cognition & Sleep: TRT improved his mental sharpness and emotional resilience, with positive effects on sleep and daily performance—though some effects were subtle and hard to measure objectively.
• Insights into Hormone Science: He reflects on the complex role of testosterone in healthspan, noting that benefits vary greatly by individual and depend on multiple biological and contextual factors.
• Longevity, Not Just Youthfulness: Kaeberlein frames TRT not as a shortcut to staying young but as a potential tool for supporting healthy aging—when approached with care, context, and clinical insight.