Most standard checkups miss the biomarkers that matter most for longevity. Here is every test worth ordering, why it matters, and where to get them without a doctor.
The standard annual physical in most Western countries is woefully inadequate from a longevity perspective. A typical panel might check your cholesterol (usually just total, LDL, HDL, and triglycerides), your complete blood count, and perhaps a basic metabolic panel. What it misses — the markers that most powerfully predict your trajectory toward or away from the major diseases of aging — is far more instructive than what it includes.
The reason for this inadequacy is partly historical (blood tests were expensive and limited decades ago when standard panels were established), partly cultural (medicine has been reactive rather than proactive), and partly economic (more testing costs more money in fee-for-service systems). But the cost of comprehensive blood testing has fallen dramatically, and the direct-to-consumer testing market now makes most longevity-relevant biomarkers accessible to anyone willing to seek them out.
This guide covers the comprehensive blood testing panel that longevity-focused physicians now consider essential, why each marker matters, and where to access these tests without waiting for a physician to order them.
ApoB (Apolipoprotein B): This is arguably the most important single cardiovascular biomarker and is almost never ordered in standard panels, despite being one of the most significant advances in cardiovascular risk assessment of the past two decades. Every atherogenic particle in your blood — LDL, VLDL, IDL, Lp(a) — carries exactly one ApoB molecule on its surface. ApoB therefore counts the total number of atherogenic particles rather than measuring the concentration of cholesterol they contain.
This distinction matters because you can have a low LDL-C (cholesterol concentration) while having high ApoB (many small, dense particles), which carries elevated cardiovascular risk. The particle count is more predictive than the cholesterol content. Peter Attia considers ApoB the primary lipid target and sets aggressive thresholds: below 60 mg/dL for those at elevated risk, below 80 mg/dL as a reasonable target for most people. Standard panels report LDL-C, which often misses the problem.
Lp(a) (Lipoprotein(a)): A genetically determined variant of LDL that is independently associated with a doubling of cardiovascular risk in those with elevated levels. Approximately 20% of the population has elevated Lp(a) (above 50 mg/dL), and the vast majority have never been tested. Lp(a) is largely genetically determined — it does not respond significantly to diet or most medications — making it essential to know your baseline. If your Lp(a) is elevated, this should inform more aggressive management of modifiable cardiovascular risk factors. This marker only needs to be measured once — it does not change significantly with lifestyle. Optimal: below 30 mg/dL.
Coronary Artery Calcium (CAC) Score: Not a blood test but a low-radiation CT scan (typically $100-150 out of pocket, not covered by most insurance) that directly quantifies the presence of calcified plaque in coronary arteries. A CAC of 0 carries very low 10-year cardiovascular risk regardless of lipid levels. A score above 100 indicates established atherosclerosis and markedly elevates risk. This single test can override standard risk models, dramatically change treatment decisions, and provide the most direct available window into whether atherosclerotic cardiovascular disease is actually developing.
Homocysteine: Elevated homocysteine is associated with cardiovascular disease, stroke, and cognitive decline. It is typically elevated due to deficiencies in B vitamins (B6, B12, folate) or specific genetic variants in the MTHFR gene. Critically, elevated homocysteine is modifiable with B vitamin supplementation — making it an actionable cardiovascular risk factor. Optimal: below 8 umol/L.
High-sensitivity CRP (hsCRP): A marker of systemic inflammation that predicts cardiovascular events independently of traditional risk factors. The JUPITER trial demonstrated that statin therapy reduced events significantly in people with normal LDL but elevated hsCRP, validating inflammation as an independent cardiovascular risk pathway. Optimal: below 1 mg/L. Values above 3 mg/L suggest significant systemic inflammation requiring investigation.
Fasting Insulin: Standard glucose tests miss insulin resistance until it is quite advanced because the body compensates by secreting more insulin to maintain normal glucose levels. Fasting insulin is a much earlier signal of metabolic dysfunction — it rises years before glucose becomes abnormal. In insulin-resistant individuals, the elevated insulin drives weight gain, hypertension, elevated triglycerides, and inflammation. Optimal fasting insulin: below 5 uIU/mL; concerning: above 10 uIU/mL; clearly abnormal: above 15 uIU/mL.
HbA1c (Haemoglobin A1c): Reflects average blood glucose over the preceding 2-3 months by measuring the percentage of haemoglobin that has become glycated (glucose-attached). Optimal for longevity purposes: below 5.4%. Values between 5.5-5.6% indicate early metabolic dysfunction even though they fall within the conventional "normal" range. Values above 5.7% meet the ADA definition of prediabetes.
HOMA-IR: Calculated from fasting glucose and fasting insulin using the formula (fasting insulin x fasting glucose) / 405, this index estimates insulin resistance. Optimal: below 1.0. Values above 2.0 indicate meaningful insulin resistance.
Uric Acid: Elevated uric acid — beyond its well-known role in causing gout — is associated with hypertension, metabolic syndrome, non-alcoholic fatty liver disease, and cardiovascular risk. Optimal: below 5.5 mg/dL in men, below 4.5 mg/dL in women. High fructose intake, alcohol, red meat, and certain medications elevate uric acid.
Free and Total Testosterone: Declining testosterone in both men and women predicts sarcopenia, metabolic dysfunction, reduced cognitive function, reduced libido, and lower quality of life. Know your baseline so that trajectory can be monitored over years. For men, total testosterone below 400 ng/dL with symptoms warrants consideration of intervention; for women, maintaining levels appropriate to their age and menopausal status is important for bone density and muscle preservation.
IGF-1 (Insulin-like Growth Factor 1): IGF-1 reflects growth hormone status and overall tissue anabolism. Both very high IGF-1 (associated with cancer risk) and very low IGF-1 (associated with sarcopenia and premature aging) are linked to adverse outcomes. Optimal range for longevity: 100-200 ng/mL in adults, with lower values in older adults being acceptable.
TSH (Thyroid Stimulating Hormone) with free T3 and free T4: Thyroid dysfunction is common — affecting approximately 10% of the population — frequently underdiagnosed, and causes significant metabolic disruption ranging from fatigue and weight gain (hypothyroid) to cardiac arrhythmias and bone loss (hyperthyroid). TSH alone is insufficient for a complete picture; requesting the full thyroid panel including free T3 and free T4 provides a more complete assessment.
DHEA-S (Dehydroepiandrosterone Sulphate): A precursor to both testosterone and oestrogen produced by the adrenal glands, DHEA-S declines with age and low levels are associated with higher all-cause mortality in some studies, particularly in men.
Cortisol (fasting morning): Chronically elevated cortisol from long-term stress drives inflammation, visceral fat accumulation, cognitive decline, and immune suppression. A morning fasting cortisol test provides a baseline; unusually elevated values warrant investigation of cortisol dynamics throughout the day.
25-Hydroxyvitamin D: Most people in northern latitudes are significantly deficient, with studies suggesting 40-70% of adults have levels below optimal. Optimal for longevity: 40-60 ng/mL. Multiple meta-analyses find associations between vitamin D deficiency and higher all-cause mortality, with the relationship most pronounced below 20 ng/mL. Many people need 3,000-5,000 IU/day of Vitamin D3 to maintain optimal levels.
Omega-3 Index: The percentage of EPA + DHA in red blood cell membranes, reflecting long-term omega-3 status more accurately than blood plasma levels. Optimal: above 8%. Below 4% is associated with significantly elevated cardiovascular risk. A 2021 meta-analysis in the Journal of Clinical Lipidology found that the omega-3 index predicted heart attack risk comparably to total cholesterol, yet it is almost never routinely measured. Nordic Naturals Omega-3 Liquids or similar high-quality fish oil can improve a low omega-3 index within months.
Ferritin: While most commonly associated with iron deficiency anaemia, ferritin is also an acute phase reactant that rises in the context of chronic inflammation. Optimal: 50-100 ng/mL for men; 30-80 ng/mL for women. Both very low ferritin (iron deficiency, fatigue, cognitive impairment) and very high ferritin (haemochromatosis, liver disease, inflammatory burden) are problematic.
B12 and folate: Particularly important for those eating plant-heavy diets (B12 is found almost exclusively in animal products), taking metformin (which depletes B12 through impaired absorption), or over age 65 (gastric absorption of B12 from food declines with age due to reduced acid secretion).
Magnesium (RBC Magnesium): Standard serum magnesium is insensitive to true deficiency because the body maintains serum levels at the expense of cellular stores until deficiency is severe. RBC magnesium better reflects cellular magnesium status. Deficiency is extremely common and associated with hypertension, insulin resistance, cardiovascular disease, and sleep disorders.
Complete Metabolic Panel: Including creatinine and eGFR (kidney filtration capacity), AST/ALT (liver enzyme markers of hepatocellular damage), bilirubin, albumin (liver synthetic function), and electrolytes.
GGT (Gamma-Glutamyltransferase): A more sensitive early marker of liver health and oxidative stress than standard ALT. Elevated GGT independently predicts all-cause mortality even within the so-called "normal" range. It is particularly sensitive to alcohol consumption and oxidative stress and has been called a "canary in the coal mine" for systemic oxidative damage.
Complete Blood Count with differential: Haemoglobin, haematocrit, platelet count, and the five-part white cell differential. The neutrophil-to-lymphocyte ratio (NLR) can be derived from this and serves as an emerging marker of immune aging (inflammaging) — higher NLR is associated with higher biological age and poorer outcomes.
In the United States, direct-to-consumer lab testing has made most of these tests accessible without a physician's order:
InsideTracker: Comprehensive blood testing optimised specifically for longevity, with personalised actionable recommendations based on your results. Their Ultimate plan covers most of the markers above and includes algorithm-based guidance on lifestyle changes to optimise each biomarker.
Marek Health: Offers comprehensive panels with physician oversight, hormone optimisation services, and particularly useful for men interested in testosterone optimisation with appropriate medical supervision.
Function Health: Founded by Mark Hyman, MD, offers 100+ biomarker testing panels with physician-reviewed results and a digital health platform for tracking results over time.
Ulta Lab Tests or Any Lab Test Now: For individual tests ordered a la carte at very low cost without any subscription or platform fees.
The goal of this testing is not to create anxiety over numbers but to reveal what is happening in your body years or decades before clinical disease would become apparent. Most of the diseases that kill people in wealthy countries — cardiovascular disease, type 2 diabetes, Alzheimer's — have decade-long preclinical periods during which they are detectable and largely modifiable with lifestyle intervention. Comprehensive blood testing provides the data infrastructure that makes genuinely proactive longevity medicine possible.