Testosterone Replacement After 55: What the TRAVERSE Trial Found

Testosterone replacement therapy in older men has been one of the most commercially promoted and scientifically contested interventions in aging medicine for two decades. Earlier observational studies and small trials raised concerns that testosterone replacement might increase cardiovascular events, prompting a 2015 Food and Drug Administration safety labeling change. The TRAVERSE trial — a randomized controlled trial of over five thousand men published in the New England Journal of Medicine in 2023 — was designed specifically to resolve the cardiovascular safety question. Its finding was nuanced: testosterone replacement did not significantly increase major adverse cardiovascular events compared to placebo. But it did significantly increase rates of atrial fibrillation, pulmonary embolism, and acute kidney injury. The results reframe the cardiovascular safety conversation without ending it. Testosterone levels decline approximately one to two percent per year in men beginning in their late thirties and forties, and by age sixty, a substantial proportion of men have serum testosterone levels below the thresholds used to define hypogonadism. This decline is associated — in observational studies — with reductions in muscle mass, bone density, energy, libido, and mood, and with increases in fat mass and insulin resistance. Whether correcting low testosterone through replacement therapy reverses these changes, improves quality of life, and does so safely has been the subject of active --- Paper cited: Cardiovascular safety of testosterone-replacement therapy Authors: Lincoff AM, Bhasin S, Flevaris P, Mitchell LM, Basaria S, Boden WE, Cunningham GR, Granger CB, Kumbhani DJ, Lam CS, Pencina MJ, Rossouw JE, Snyder PJ, Wenger NK, Wolski K, for the TRAVERSE Study Investigators Journal: New England Journal of Medicine Year: 2023 DOI: 10.1056/NEJMoa2215025 --- Subscribe for one peer-reviewed paper made practical, every Tuesday and Friday. Free guide: How to Read Your Biomarker Panel at 55+ - {{LEAD_MAGNET_URL}} --- EDUCATIONAL CONTENT - NOT MEDICAL ADVICE This video is for general educational and informational purposes only. It summarizes peer-reviewed research. It does NOT constitute: - Medical advice, diagnosis, or treatment - Recommendations to start, stop, or change any medication - Dosing instructions for supplements or interventions - A substitute for consultation with a licensed physician Before applying anything discussed: - Talk to your physician, especially if you take prescription medications (statins, metformin, blood thinners, antihypertensives, GLP-1 agonists, etc.) - Discuss interactions, contraindications, and your individual risk profile - Get baseline biomarkers before changing your regimen if relevant Specific cautions: - Intermittent fasting: not appropriate for people with diabetes (especially Type 1), history of eating disorders, pregnancy, or underweight status without medical supervision. - Strength/Zone-2 training: medical clearance recommended for cardiovascular or joint conditions before initiating new training loads. - Supplements: third-party tested products preferred; verify drug interactions. AFFILIATE DISCLOSURE (FTC compliant): Some links in the description may be affiliate links. We may earn a commission at no additional cost to you. We only feature products and tools relevant to the research discussed. AI-ASSISTED PRODUCTION: Voice narration is generated via Edge TTS (Microsoft Neural Voice). Research, scriptwriting, and review are conducted by a human editor before publication. Reviewed: 2026-09-04