The Complete Longevity Lab Testing Guide: What to Test, When, and What the Numbers Mean

The gap between what standard medical care measures and what longevity-optimized care requires is substantial. A typical annual physical with standard bloodwork orders: CBC, CMP (comprehensive metabolic panel), standard lipid panel (total cholesterol, LDL-C, HDL-C, triglycerides), TSH, and perhaps HbA1c. This panel is designed to detect established disease — anemia, kidney disease, diabetes, thyroid disease, and hyperlipidemia by standard definitions. It was not designed to optimize for longevity or to detect the early upstream dysfunction that precedes disease by 10 to 20 years.

This guide presents the longevity-optimized testing framework: organized by category, with longevity-optimized target ranges alongside standard reference ranges, testing frequency recommendations, and the clinical significance of each marker.

What standard bloodwork covers, and what it misses

A typical annual physical includes a complete blood count, a comprehensive metabolic panel, a standard lipid panel (total, LDL and HDL cholesterol and triglycerides) and often TSH and HbA1c. These tests are designed to find anemia, kidney disease, diabetes, thyroid disease and high cholesterol once they meet diagnostic definitions. A few additional tests say much more about risk that is still developing, and most are available from standard commercial labs.

Cardiovascular risk

ApoB: counting the particles

Apolipoprotein B sits on every particle that can lodge in an artery wall (VLDL, IDL, LDL and Lp(a)), one molecule per particle, so the ApoB level is a count of atherogenic particles. LDL cholesterol measures how much cholesterol those particles carry, and the two can diverge, especially in people with insulin resistance, whose LDL particles tend to be smaller and carry less cholesterol each. A meta-analysis of the major prospective studies estimated that a treatment strategy based on ApoB would prevent more cardiovascular events than one based on LDL or non-HDL cholesterol.¹ In the Framingham Offspring Study, LDL particle number tracked risk better than LDL cholesterol when the two disagreed.³

The 2018 US cholesterol guideline treated an ApoB of 130 mg/dL or more as a risk-enhancing factor; the 2026 guideline replaced it.² How much lower to aim depends on overall risk: many preventive cardiologists aim below 80 mg/dL, and lower in people with established heart disease or diabetes. That is a target to set with a clinician, not a laboratory cut-off. More in our ApoB article.

Lp(a): test once

Lipoprotein(a) is an LDL-like particle with an extra protein, apolipoprotein(a), attached. Its level is set mainly by genes and changes little with diet or exercise. A European Atherosclerosis Society consensus concluded that elevated Lp(a) is a cause of premature cardiovascular disease, with risk rising continuously rather than above a single threshold, and recommended a desirable level below about 50 mg/dL, roughly the 80th percentile.⁴ The 2026 US dyslipidemia guideline counts 50 mg/dL (125 nmol/L) or more as a risk-enhancing factor.¹⁷

Because the level is largely inherited, one measurement is enough for most adults. No approved drug lowers Lp(a) specifically; RNA-based drugs designed to do so were in phase 3 trials in 2025. Until then, a high result is a reason to manage the risk factors you can change more aggressively. More in our Lp(a) article.

hsCRP: inflammation in the arteries

High-sensitivity C-reactive protein (hsCRP) measures low-grade inflammation and is reported in milligrams per liter. In the JUPITER trial, 17,802 people with LDL cholesterol below 130 mg/dL but hsCRP of 2.0 mg/L or more were randomized to rosuvastatin or placebo; the statin cut the combined rate of heart attack, stroke, revascularization, unstable angina and cardiovascular death by 44% over a median of 1.9 years.⁵ The 2018 US guideline treated an hsCRP of 2.0 mg/L or more as a risk-enhancing factor.² Any infection or injury raises hsCRP for a while, so a high reading is worth repeating before acting on it.

Other cardiovascular tests

NMR lipoprotein testing reports LDL particle number and size.³ Apolipoprotein A1, fibrinogen and interleukin-6 are also available from some labs; they add detail, but there is less evidence for acting on them than for ApoB, Lp(a) and hsCRP.

Metabolic health

Fasting insulin and HOMA-IR

As insulin resistance develops, the pancreas makes more insulin to keep blood sugar normal, so insulin rises for years before fasting glucose does. Joseph Kraft's insulin-response studies described this pattern in the 1970s.⁶ HOMA-IR combines the two fasting values: fasting insulin (µIU/mL) multiplied by fasting glucose (mg/dL), divided by 405. Cut-offs for insulin resistance vary by population and lab, commonly between about 2 and 2.9; lower is better, and there is no agreed "optimal" value. More in our fasting insulin and HOMA-IR article.

HbA1c and fasting glucose

HbA1c reflects average blood sugar over about three months. Below 5.7% is normal, 5.7% to 6.4% indicates prediabetes, and 6.5% or more indicates diabetes. In the EPIC-Norfolk cohort of 4,662 men, the risk of death rose continuously with HbA1c across the whole range, including the normal range, and was lowest in men below 5%; each one-point increase was associated with 28% higher mortality, independent of age, blood pressure, cholesterol, body mass index and smoking.⁷

Triglycerides, HDL and uric acid

In a study that followed 7,735 middle-aged British men for about 13 years, body mass index was the strongest predictor of type 2 diabetes, and higher triglycerides, lower HDL cholesterol, a higher heart rate and higher uric acid also predicted it.⁸ Fasting triglycerides of 150 mg/dL or more are a standard threshold, and the 2018 US guideline treated persistently elevated triglycerides (175 mg/dL or more) as a risk-enhancing factor.² The ratio of triglycerides to HDL is sometimes used as a rough marker of insulin resistance. More in our uric acid article.

Hormones

Testosterone and estradiol

For men with symptoms such as low libido, fatigue or loss of morning erections, testosterone is measured in the morning while fasting and repeated if low. The Endocrine Society recommends diagnosing low testosterone only when symptoms and consistently low levels coincide, using the lower limit of a standardized reference range (264 ng/dL in the harmonized range it cites); free testosterone helps when SHBG is abnormal.⁹ In women around menopause, estradiol and FSH fluctuate widely and are interpreted together with symptoms. More in our testosterone article.

Thyroid

Guidelines use TSH as the first test of thyroid function, adding free T4 when TSH is abnormal; measuring T3 is not recommended for diagnosing hypothyroidism.¹⁰ Subclinical hypothyroidism, a raised TSH with normal free T4, becomes more common with age, and whether to treat it depends on how high TSH is, age and symptoms. More in our thyroid article.

Nutritional markers

Homocysteine

Homocysteine rises when vitamin B12, folate or B6 is low, with kidney disease and with some genetic variants. In a meta-analysis of observational studies, a 25% lower homocysteine level (about 3 µmol/L) was associated with an 11% lower risk of heart disease and a 19% lower risk of stroke, which the authors described as at most a modest independent effect.¹¹ Trials that lowered homocysteine with B vitamins did not reduce heart attacks or deaths: a Cochrane review of 12 trials in 46,699 people found no difference in heart attacks (relative risk 1.02).¹² Testing is useful for uncovering B12 or folate deficiency; lowering homocysteine to protect the heart is not supported. More in our homocysteine article.

Vitamin D

Low vitamin D levels are linked to worse health in observational studies, but correcting them with supplements has mostly not changed outcomes. In the VITAL trial, 25,871 adults took 2,000 IU of vitamin D3 a day or placebo for a median of 5.3 years; supplementation did not lower the rate of cancer or of major cardiovascular events.¹³ Deficiency is usually defined as below 20 ng/mL. Testing makes most sense for people at higher risk of deficiency, such as those with little sun exposure, darker skin, malabsorption or osteoporosis. More in our vitamin D article.

Blood count and ferritin

A complete blood count detects anemia, which is common in older adults and easy to miss. Ferritin reflects iron stores: low values mean iron deficiency, while high values can mean iron overload or simply inflammation, so a high ferritin is read alongside transferrin saturation before investigating conditions such as hemochromatosis. More in our iron article.

Biological age tests

Consumer epigenetic tests estimate biological age from DNA methylation and often report several "clocks". GrimAge, built from methylation markers of plasma proteins and smoking history, predicted time to death and to disease in large validation cohorts.¹⁴ DunedinPACE measures the pace of aging; in the CALERIE trial, two years of calorie restriction slowed DunedinPACE while other clocks did not change significantly.¹⁵ Results can differ between labs and between repeat samples, and these tests are research tools rather than diagnoses. More in Epigenetic Clocks Explained.

Standard ranges and the tighter targets some clinicians use

Many longevity-focused clinicians aim for values tighter than standard laboratory reference ranges, an approach popularized by books such as Outlive.¹⁶ Most of these tighter targets have not been tested in trials as treatment goals, and some, such as the vitamin D target, conflict with the trial results above. Treat the right-hand column as questions to discuss with your clinician, not as diagnoses.

How often to test

This is a reasonable schedule rather than a guideline. A single abnormal value usually needs repeating before it is acted on.

Getting the tests ordered

Many clinicians will order ApoB, Lp(a), fasting insulin and hsCRP if asked. In most US states, direct-to-consumer lab services also let you order tests yourself. Either way, review results with a clinician who knows your history.

Derek Giordano

Founder & Editor, IQ Healthspan

Derek Giordano is the founder and editor of IQ Healthspan. A father of four with a lifelong interest in athletics, fitness and the supplement industry, he built the site to show what the research actually supports. Derek is not a physician: articles cite peer-reviewed studies with numbered references you can check, and corrections are logged publicly. Articles are researched, drafted and fact-checked with the help of AI tools, and every claim is checked against the studies it cites. IQ Healthspan has no supplement brand partnerships, affiliate relationships or financial conflicts of interest.

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Sources Listed With Numbered Citations

17 references at the end of this article, each linked to its PubMed record or identified as a book