Biomarker Educational Library
A physician-reviewed, evidence-based guide to every biomarker VitalDrop measures — what it tests, optimal ranges, why it matters, and how to track it. Each entry includes peer-reviewed references and clinical context for informed health decisions.
Hormones & Vitality
View category panelTotal Testosterone
The master anabolic hormone driving muscle mass, libido, drive, bone density, and mood — in both men and women.
Free Testosterone
The biologically active fraction of testosterone your tissues can actually use — often the missing piece when total testosterone looks 'normal.'
Bioavailable Testosterone
The fraction of testosterone your tissues can actually use — free testosterone plus the albumin-bound portion that readily dissociates.
Estradiol (E2)
The primary estrogen — essential for bone density, cardiovascular protection, brain health, and reproductive function in both sexes.
Progesterone
The hormone that balances estrogen, supports sleep and mood, and regulates the menstrual cycle and fertility.
SHBG (Sex Hormone-Binding Globulin)
The protein that binds sex hormones — the key to understanding why your 'normal' testosterone may not be working.
DHEA-S
The most abundant adrenal hormone — a precursor to testosterone and estrogen and a marker of stress resilience.
Cortisol
Your primary stress hormone — essential in the right amounts, but chronically elevated it disrupts sleep, metabolism, and immune function.
Metabolic & Thyroid
View category panelTSH (Thyroid Stimulating Hormone)
The pituitary's signal to the thyroid — the most sensitive first indicator of thyroid dysfunction.
Free T3 (Triiodothyronine)
The active thyroid hormone your cells actually use for energy and metabolism.
Free T4 (Thyroxine)
The primary hormone the thyroid produces — the raw material your body converts into active T3.
HbA1c (Glycated Hemoglobin)
Your 3-month average blood sugar — the clinical standard for screening prediabetes and diabetes.
Fasting Glucose
Your immediate blood sugar level after fasting — a snapshot of insulin sensitivity and metabolic health.
Cardiovascular
View category panelLDL Cholesterol
The 'bad' cholesterol — a foundational cardiovascular risk marker tracked in nearly every lipid panel.
HDL Cholesterol
The 'protective' cholesterol that carries plaque away from arteries — low HDL is a cardiovascular risk marker.
Triglycerides
Circulating blood fats from carbohydrate metabolism — elevated triglycerides signal metabolic strain and insulin resistance.
hs-CRP (High-Sensitivity CRP)
A sensitive measure of systemic inflammation — the process that turns stable plaque into heart attacks.
Nutrients & Organ Health
View category panelVitamin D (25-OH)
The sunshine vitamin — essential for immune function, bone health, and mood, and remarkably commonly deficient.
Ferritin
Your body's iron storage protein — both deficiency and overload impair energy, performance, and health.
Creatinine
A waste product filtered by the kidneys — the foundational marker for assessing kidney filtration.
eGFR (Estimated Glomerular Filtration Rate)
The clinical standard for kidney function — how efficiently your kidneys filter blood.
Hemoglobin
The iron-rich protein that carries oxygen to every tissue — low levels mean fatigue and reduced endurance.
Hematocrit
The percentage of blood made up of red cells — a proxy for hydration and oxygen-carrying capacity.
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