Blood test interpretation

Learn how to read and understand common lab markers that affect men’s health, performance, and hormone optimization—like total and free testosterone, estradiol, SHBG, lipids, CBC, CMP, A1C, thyroid, and inflammatory markers. This tag helps you spot what’s normal vs. concerning, know what to retest, and make smarter decisions about training, nutrition, supplements, and TRT with your clinician.

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The essentials for blood test interpretation — then explore the latest posts below.

Got “Normal” testosterone on Function Health but still feel off? How to interpret results and plan next steps.

Got “Normal” testosterone on Function Health but still feel off? How to interpret results and plan next steps.

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Feb 09, 2026 · 11 min read

A testosterone result can be “normal” and still feel off because testosterone deficiency is diagnosed by symptoms plus consistently low morning total testosterone on repeat testing (often around ~300 ng/dL), and total testosterone can look adequate while free testosterone is low when SHBG is elevated. Here’s how to decide when a repeat draw matters, which ...

Blueprint stack review: What Bryan Johnson’s simplified longevity stack can and can’t do for men

Blueprint stack review: What Bryan Johnson’s simplified longevity stack can and can’t do for men

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Jan 30, 2026 · 11 min read

Bryan Johnson’s commercial “Blueprint Stack” promises a simplified route into a longevity-focused routine. This blueprint stack review breaks down what’s actually in the stack as described, what the research says about the major components for men, and how to use a “stack” approach without drifting into expensive guesswork. “If a ‘stack’ helps you consistently hit ...

The hidden link between inflammation and heart disease: Why cholesterol is only half the story

The hidden link between inflammation and heart disease: Why cholesterol is only half the story

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Jan 28, 2026 · 10 min read

Chronic arterial inflammation can turn LDL-based plaque dangerous by driving cytokine signaling (IL‑1β, IL‑6) that recruits macrophages and releases metalloproteinases to thin the fibrous cap until it ruptures, which helps explain why nearly 50% of heart attacks occur in men with “normal” cholesterol. A standard lipid panel won’t capture that risk, so this article breaks ...

Athlete biomarker testing for longevity: The lab numbers that keep men performing longer

Athlete biomarker testing for longevity: The lab numbers that keep men performing longer

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Jan 19, 2026 · 11 min read

For longevity-focused men who train, repeating key labs—especially HbA1c (a ~3‑month average of blood sugar) and ApoB (the number of atherogenic particles that can enter artery walls)—can reveal early metabolic drift and cardiovascular risk before performance drops or disease shows up. Pair those with iron, inflammation, and hormone/recovery markers to build a “healthspan dashboard” that ...

What is biohacking? The science of optimizing male biology

What is biohacking? The science of optimizing male biology

Dr. Susan Carter, MD avatar
Dr. Susan Carter, MD: Endocrinologist & Longevity Expert
Jan 03, 2026 · 10 min read

Biohacking is a data-driven approach to improving physiology by measuring key biomarkers (such as glucose, cortisol, and testosterone), changing lifestyle or environmental inputs, and re-testing using a “measure, modify, measure” loop. Here’s how mechanisms like epigenetic regulation and hormesis can help counter modern stressors and extend healthspan. “Biohacking is often marketed as a shortcut, but ...

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