Explore Dr. Retzler’s HormoneSynergy® Longevity Medicine Resource Library

Longevity Medicine, Functional Wellness & Anti-Aging Insights from HormoneSynergy®

Welcome to the HormoneSynergy® Longevity Medicine Blog, a physician-guided clinical library led by Dr. Kathryn Retzler. Our articles cover the systems that most often shape health with age: metabolic health, hormones, cardiovascular and kidney risk, body composition, bone and muscle, brain health, sleep, gut health, nutrition, supplements, and the biology of aging.

The library is organized around clinical questions rather than trends. Some articles review new research. Others explain testing, treatment, nutrition, or a condition patients commonly encounter. Across the collection, the standard is the same: evidence first, appropriate uncertainty, and enough clinical context to separate useful medicine from wellness marketing.

Start with the HormoneSynergy® Longevity Medicine Framework

New & recently updated:

Metabolic Health & Insulin Resistance

Clinical resources on insulin resistance, glucose regulation, metabolic syndrome, visceral fat, prediabetes, obesity and GLP-1-based care within a broader longevity medicine plan.

Kidney Health & Cardiovascular-Kidney-Metabolic Health

Kidney health belongs in the same clinical conversation as blood pressure, diabetes, insulin resistance, obesity and cardiovascular risk. These resources cover early detection, CKD, albuminuria, nutrition and CKM health.

Gut Health, Microbiome & Immune Signaling

Clinical education on the microbiome, intestinal barrier, fiber, inflammation, gut-brain signaling, immune biology and the growing connections between gut, metabolic and kidney health.

Food Quality, Vitamins, Supplements & Wellness Claims

Evidence-based guidance on nutrient gaps, supplement quality, interactions, food claims and longevity products, with an emphasis on where supplementation helps and where marketing outruns the evidence.

  • Cleerly Heart Analysis: The New Test That Detects Heart Disease Years Before Symptoms

    Advanced Cleerly Testing Portland and Lake Oswego OR USA

    Cleerly coronary plaque analysis is an AI-based assessment of coronary CT angiography that can detect and quantify plaque in the heart’s arteries—including soft plaque—often years before symptoms appear. Learn what the Cleerly heart scan shows, who it’s for, and how to use results for prevention.

  • The 7 Tests That Detect Heart Disease Before Symptoms

    Symptoms of Heart Disease Portland and Lake Oswego OR USA

    Most heart disease builds silently for years. These seven tests can reveal hidden risk earlier—often long before symptoms appear—so you can prevent the crisis.

  • Cleerly vs Calcium Score: Which Detect Heart Disease Before Symptoms Is Better?

    Advanced Cardiovascular Testing Cleerly Portland OR USA

    Calcium scoring can be useful, but it doesn’t detect everything. Here’s how Cleerly coronary plaque analysis differs and when each test may be the right fit.

  • Hidden Heart Disease: Why Heart Attacks Strike Without Warning

    Heart Health and Advanced Cardiovascular Testing Lake Oswego OR USA

    Many people feel fine until the day they have a heart attack. Learn why coronary plaque often develops silently and how preventive cardiology testing can uncover hidden heart disease early.

  • Digital Overload, Stress Hormones, and Longevity: What Constant Input Is Doing to Your Body

    Digital overload and stress hormones illustration showing nighttime phone use disrupting cortisol rhythm compared to healthy morning light circadian pattern HormoneSynergy Longevity Medicine

    Constant digital stimulation doesn’t just affect your focus—it impacts cortisol, sleep, insulin resistance, and long-term health. A clinical look at digital overload and longevity.

  • Fasting Insulin and Metabolic Health: What Your Levels Really Mean

    Fasting insulin and metabolic health concept showing physician reviewing lab data with patient and subtle glucose insulin relationship visualization HormoneSynergy Portland Oregon USA

    Fasting insulin is one of the earliest indicators of metabolic health and insulin resistance. Learn what your levels mean from a longevity medicine perspective.

  • New Research Review: Collagen Supplements May Improve Aging Skin

    New Research Review: Collagen Supplements May Improve Aging Skin

    A growing body of research suggests collagen supplements may support healthier aging skin by improving hydration, elasticity, and wrinkles. At HormoneSynergy®, we examine what the science actually shows.

  • Menopause and Brain Health: The Complete Guide

    Doctors Menopause and brain health guide

    Menopause can affect memory, concentration, mood, sleep, brain metabolism, and long-term cognitive health. This complete guide explains menopause brain fog, estrogen and brain function, new 2026 dementia research, hormone therapy, and the cardiovascular, metabolic, sleep, and lifestyle factors that support healthy brain aging.

  • At What Age Does Menopause Affect the Brain?

    menopause and hormone doctor portland and lake oswego oregon

    Brain fog, memory changes, and sleep disruption often begin during perimenopause—sometimes years before menopause itself. Learn what age brain changes typically begin and how to protect cognitive health.

  • Estrogen and Alzheimer’s Risk: What Women Need to Know

    Estrogen and Alzheimer’s Risk: What Women Need to Know

    Estrogen plays an important role in brain health and may influence Alzheimer’s risk in women. Learn how menopause affects the brain and what research suggests about hormone therapy and cognitive aging.

  • Menopause Brain Fog Is Real. It Is Not Usually Dementia.

    Midlife woman discussing menopause-related brain fog, memory, sleep, and hormone changes with a physician in a clinical consultation room.

    Brain fog during menopause is common. It can feel alarming, especially for women who have always relied on sharp memory, verbal fluency, and focus. In many cases, the issue is not dementia. It is the brain adapting to a new hormonal, metabolic, and sleep environment.

  • Menopause, Brain Health, and Gray Matter: What Every Woman Should Know

    Menopause, Brain Health, and Gray Matter: What Every Woman Should Know

    New research shows menopause may affect brain structure and mental health. Learn how hormonal shifts influence gray matter, cognition, and sleep—and what women can do to protect brain health during midlife and beyond.