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.

  • Menopause Care Is Booming. Medicine Still Has to Come First.

    Female physician discussing individualized, evidence-based menopause and preventive longevity care with a midlife patient at HormoneSynergy.

    A recent JAMA article examines the rapidly expanding menopause marketplace—and the uncomfortable overlap between legitimate medical care, weak evidence, influencer enthusiasm, and product sales. HormoneSynergy works in this same clinical territory, but our model is built around individualized physician judgment, diagnostic context, informed consent, and the willingness to recommend less—not simply sell more.

  • A Walk Does Not Need a Point

    Aria, a fluffy black Shepherd-Doodle with a white beard and chest patch, walks on a leash along a leafy neighborhood sidewalk.

    Aria set out to write something meaningful and came up empty. Then Dr. Retzler took her for a walk, and that may have been enough. Not every moment needs to become insight, content, or a metaphor. Sometimes the lesson is simply to pay attention.

  • Ultra-Processed Food Is a Problem. The Ingredient List Is Not a Crime Scene.

    Woman calmly reading a packaged-food ingredient label while shopping for a balanced mix of fresh and convenient foods.

    Ultra-processed foods deserve scrutiny, but long ingredient names are not proof of toxicity. The more useful question is how the food affects appetite, diet quality and what it regularly replaces.

  • We Sell Supplements. Here Is How We Keep That From Becoming Wellness Marketing.

    Dr. Kathryn Retzler discussing an individualized care plan with a patient at HormoneSynergy®, with RetzlerRx® supplements and the clinic’s evidence-based supplement philosophy displayed.

    HormoneSynergy® sells nutritional supplements and may receive revenue from those sales. Here is how we approach that financial relationship, product quality, clinical evidence, patient choice, and the responsibility to recommend less when less is appropriate.

  • High Blood Pressure Can Weaken More Than the Heart

    Medical illustration of the heart and thoracic aorta beside a blood-pressure monitor, showing how chronic hypertension can place stress on the aortic wall.

    High blood pressure is usually discussed in terms of heart attacks, strokes, and kidney disease. It can also place years of mechanical stress on the aorta, increasing the risk of aneurysm and aortic dissection. The emergency may happen suddenly, but the vulnerability often develops quietly.

  • Photon-Counting CT Does Not Replace Cleerly. It May Make It Better.

    Female cardiac imaging physician reviewing a coronary CT angiogram from an advanced photon-counting CT scanner and evaluating coronary plaque.

    Photon-counting CT may produce clearer coronary images, particularly in heavily calcified arteries and vessels containing stents. Cleerly does something different: it analyzes CCTA images to quantify plaque and narrowing. The future may not be one versus the other, but better scanning followed by validated AI analysis.

  • Inflammation Is Not the Enemy. Omega-3s Are Not Always the Answer.

    Medical illustration of cerebral blood vessels repairing after brain injury, showing inflammation and EPA omega-3 activity as context-dependent biological processes.

    Omega-3 fatty acids are often presented as universally protective for the brain. New animal research suggests the biology is more complicated, particularly after repetitive brain injury. The study does not prove that fish oil harms people, but it offers a useful reminder: inflammation has a role in healing, and suppressing it is not always the same as supporting recovery.

  • Micronized Pregnenolone vs. Sustained-Release Pregnenolone: Does the Formulation Matter?

    Comparison of micronized immediate-release and sustained-release pregnenolone formulations from HormoneSynergy®

    Micronized and sustained-release pregnenolone contain the same hormone, but they do not deliver it in quite the same way. Here is what the formulation may change—and what the evidence has not established.

  • Hospitals Are Not Your Health Plan. They Are There When the Plan Fails.

    Hospital physician discussing recovery, nutrition and preventive health responsibilities with a patient.

    We often hear that hospitals do not care about nutrition and only make people sicker. There are legitimate criticisms of modern healthcare, including rushed visits, fragmented care, medication overuse, inadequate nutrition training, and too little emphasis on prevention. But hospitals also stop heart attacks, treat infections, repair traumatic injuries, deliver babies, remove tumors, and keep critically ill people alive. Good medicine requires accountability from healthcare systems, physicians, and patients - not blanket contempt for the people providing emergency care.

  • A Popular Wellness Influencer’s Heart “Superfoods”: When Biochemistry Becomes Marketing

    Preventive cardiology physician reviewing ApoB and arterial imaging while a generic wellness influencer promotes butter, red meat, eggs and salt as heart superfoods.

    A popular wellness influencer’s list of heart superfoods contains several nutritious foods—and a remarkable number of marketing hooks. The problem is not that eggs, fish, shellfish, fermented foods or red meat can never belong in a healthy diet. It is the leap from “contains an important nutrient” to “protects your arteries,” along with claims that butter is heart medicine, sea salt fixes sleep and mainstream cardiovascular guidance should be reversed.

  • Lp(a): The Inherited Heart Risk Most People Have Never Measured

    Physician reviewing an inherited Lp(a) cardiovascular risk result with a patient during a preventive heart health consultation.

    Lp(a) is a largely inherited cardiovascular risk factor that is elevated in about one in five people. It is not a prediction of a heart attack or stroke, but it can meaningfully change how aggressively the rest of your cardiovascular risk should be managed.

  • Biological Age Tests: Can They Really Tell You How Fast You Are Aging?

    Biological Age Tests: Can They Really Tell You How Fast You Are Aging?

    Biological age tests can identify molecular and physiologic patterns associated with aging, disease risk, and mortality, but they do not literally measure how old every cell or organ in your body is. Newer tools such as GrimAge and DunedinPACE are more useful than early clocks because they were designed around health outcomes or the pace of physiologic decline rather than simply predicting chronological age. New 2026 research also shows that changes in several clocks over time can carry meaningful information. The science is becoming more useful. The marketing is still ahead of it.