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.

  • Why Am I Not Losing Weight? Measure the Right Things First

    Midlife patient and clinician reviewing body composition, sleep, and metabolic health data during a HormoneSynergy preventive longevity medicine consultation.

    Weight-loss plateaus are real. But the answer is not always more fasting, stricter keto, or blaming insulin for everything. A better question is whether we are measuring body composition, muscle, sleep, medications, hormones, insulin resistance, activity, and the actual plan clearly enough.

  • When Pain Is Real but the Injury Is Gone: Understanding Neuroplastic and Nociplastic Pain

    HormoneSynergy® clinical consultation image showing a physician and patient reviewing nervous system pain signaling and neuroplastic pain in a calm medical office.

    Persistent pain does not always mean that tissue is still being damaged. In some patients, pain continues after an injury has healed or when imaging and laboratory findings do not adequately explain the severity of symptoms. Research into nociplastic and neuroplastic pain is helping clinicians understand how altered pain processing, learned threat, fear, attention, and previous experience can contribute to persistent symptoms. The challenge is knowing when this framework is appropriate and when pain still requires further medical investigation.

  • The Women’s Health Gap Is a Prevention Gap

    Midlife woman in a prevention-focused longevity medicine consultation at HormoneSynergy, with subtle cues for hormone health, bone density, cardiovascular risk, brain health, and metabolic health.
    AI Overview: Women’s health has a long research gap, but in everyday medicine the problem often shows up as a prevention gap. Many women are not ...
  • Why the Heart Rarely Gets Cancer: Mechanobiology Without the Hype

    Editorial medical image showing heartbeat mechanics and mechanobiology concepts related to why the heart rarely develops cancer, from HormoneSynergy Longevity Medicine in Portland and Lake Oswego, Oregon.

    New research suggests the beating heart may actively suppress tumor growth through mechanical force, Nesprin-2 signaling, and chromatin remodeling. Fascinating science, but not a shortcut to cancer treatment.

  • Responsible Vaccination in an Age of Mistrust

    Physician and adult patient reviewing responsible vaccination, metabolic health and whole-person preventive care in a modern HormoneSynergy longevity medicine clinic.

    Vaccines are one of modern medicine’s clearest public-health wins, but trust has been damaged by politics, poor communication, social media distortion, and conspiracy. The responsible answer is evidence-based vaccination, informed consent, and whole-person health.

  • Ultra-Processed Foods Cannot Be Fixed by a Better Label

    Plant- and protein-forward Mediterranean meal contrasted with ultra-processed food, representing metabolic health and sustainable longevity nutrition.
    Ultra-processed foods are not just whole foods with a few missing nutrients. Processing changes texture, satiety, eating speed, food structure, and metabolic response. The answer is not food purity, but a sustainable pattern built on real food, adequate protein, fiber diversity, and metabolic stability.
  • What GLP-1s Are Teaching Us About Craving, Compulsion and the Brain

    Physician reviewing GLP-1, craving, reward pathways and compulsive behavior with a patient in a modern HormoneSynergy longevity medicine setting.

    GLP-1 medications are usually discussed as weight-loss drugs, but emerging research suggests they may also affect craving, reward, alcohol intake and compulsive behavior. The science is promising, early and worth taking seriously.

  • Multivitamins, Fitness and Diet: What Actually Slows Aging?

    Middle-aged adult in a longevity medicine clinic reviewing fitness, nutrition, and supplement data for healthy aging.

    A new article links multivitamins, fitness and diet to slower aging. The real story is more grounded: fitness matters most, food patterns matter, and supplements may help fill gaps.

  • Mitophagy: What It Is and How to Support Mitochondrial Quality Control

    Woman exercising beside a cellular illustration showing mitophagy and balanced mitochondrial removal, recycling, and replacement.

    Mitophagy helps cells remove damaged mitochondria, but it is only one part of mitochondrial quality control. Exercise remains the most defensible way to support the complete system.

  • Urolithin A Benefits and Mitophagy: What Human Trials Actually Show

    Older adult strength training with a mitochondrial health visualization illustrating urolithin A, mitophagy and longevity research.

    Urolithin A is one of the more scientifically interesting compounds in the longevity supplement market, with randomized human trials examining mitophagy, muscle function, mitochondrial biomarkers, and immune aging. The human evidence is real, but considerably narrower than many claims suggest.

  • Breast Cancer Screening Is Not One-Size-Fits-All

    Physician discussing individualized mammography and breast cancer screening with a patient at HormoneSynergy Clinic.

    Mammography guidelines provide an important starting point, but breast density, family history, genetics, previous biopsies, and personal risk may change when and how a woman should be screened.

  • MIND Meets Muscle: Comparing the MIND and Plant- and Protein-Forward Mediterranean Diet Diets for Healthy Aging

    Physician comparing MIND and protein-forward Paleo-Mediterranean foods for brain health, muscle preservation, and healthy aging at HormoneSynergy in Oregon.

    The MIND diet combines Mediterranean and DASH principles for cognitive health. HormoneSynergy® adds deliberate protein, muscle preservation, metabolic context, and individualized use of grains, legumes, and dairy.