A longevity blood test is not one single test that tells you how long you will live. The term covers everything from standard blood markers, such as glucose and cholesterol, to newer biological age tests and NAD+ testing. Some of these give doctors useful information today. Others are still developing.

NAD+ can be measured in blood, but there is an important catch. A blood NAD+ result does not currently tell us, on its own, how quickly someone is aging. New human research makes that distinction especially important. (1)

Key Takeaways:

• There is no single medically accepted blood test for longevity.

• NAD+ can be measured, but there is no agreed ideal NAD+ level for healthy aging.

• New research questions how useful whole-blood NAD+ is as a standalone aging marker.

• Established markers such as ApoB, HbA1c, glucose, and kidney function can provide more actionable health information.

What Is a Longevity Blood Test?

“Longevity blood test” is more of an umbrella term than a specific medical test.

A longevity-focused blood panel may look at markers linked with conditions that affect health and lifespan, including cardiovascular disease, diabetes, inflammation, and kidney or liver problems.

Some longevity clinics go further by adding biological age tests, hormone panels, nutritional markers, or newer biomarkers such as NAD+.

Here is a simple way to separate them:

No single result tells the full story. Think of longevity testing more like a dashboard than a speedometer.

What Is an NAD Test?

An NAD test measures nicotinamide adenine dinucleotide, or NAD+, in a biological sample.

NAD+ is involved in cellular energy production, DNA repair, and many enzyme reactions. Because of its role in cellular function, researchers have become interested in NAD+ as a potential marker related to aging.

Laboratories can measure NAD+ using methods such as mass spectrometry and enzymatic testing.

The difficult part comes after the test.

Scientists do not yet have one universally accepted NAD+ reference level that separates “young,” “old,” or “healthy” aging.

A 2022 study involving 1,518 adults found an average whole-blood NAD+ concentration of around 33.0 μmol/L. Researchers saw age-related differences among men, but the same pattern was not clear among women. (2)

That means comparing your NAD+ number with a single online “ideal range” can be misleading.

Can Your NAD Level Tell You How Well You Are Aging?

Not reliably, based on the evidence we have today.

This is where newer research has changed the conversation.

A 2026 study examined whole-blood NAD+ across seven independent human cohorts. Researchers found that NAD+ concentrations stayed relatively stable across age groups and several lifestyle interventions. They concluded that whole-blood NAD+ may have limited value as a standalone biomarker of aging. (1)

Interestingly, the researchers could detect changes after supplementation with nicotinamide riboside, an NAD+ precursor. So the testing method could pick up biological changes. The bigger issue was that normal aging itself did not produce a simple, predictable decline in whole-blood NAD+.

That helps explain an important point:

An NAD test can tell you how much NAD+ is present in the sample tested. It cannot currently tell you your biological age or how quickly you are aging.

NAD+ concentrations inside individual tissues may also behave differently from NAD+ measured in whole blood, which adds another layer of complexity.

Can a Blood Test Measure Your Biological Age?

Scientists are working on it, but biological age is not yet a single standardized measurement.

Some tests combine common blood biomarkers. Others examine DNA methylation, proteins, metabolites, or changes across several body systems.

One well-known example is DunedinPACE. Researchers developed it using changes in 19 biomarkers across multiple organ systems measured over about 20 years. The resulting DNA methylation measurement aims to estimate how quickly someone is aging rather than simply predicting their chronological age. (3)

Even these newer tests have limitations.

A 2025 systematic review examined 56 studies on biological age assessment. Researchers found several competing approaches, including PhenoAge, the Klemera-Doubal method, principal component analysis, and other scoring systems. They concluded that there is still no agreed gold standard for measuring biological age. (4)

So if a test says your biological age is 35 when you are 42, it should not be read like a clinical diagnosis.

Which Blood Tests Are Most Useful for Longevity?

For most people, the strongest starting point is not an exotic aging test. It is getting a clear picture of established health risks.

Depending on your age, medical history, and clinician's advice, that may include:

• ApoB and a standard lipid panel

• Lipoprotein(a)

• HbA1c

• Fasting glucose

• Blood pressure

• Kidney function

• Liver function

• hs-CRP

• Complete blood count

• Nutrient tests when deficiency is suspected

These measurements can identify health issues that doctors already know how to interpret and manage.

NAD+, epigenetic clocks, metabolomics, and similar tests may provide interesting extra information. Their clinical meaning is less settled.

How Often Should You Do Longevity Testing?

There is no universal schedule. How frequently you test depends on your age, health history, medications, existing conditions, and what you are measuring. A clinician may want to repeat some markers within a few months after treatment or lifestyle changes, while others may only need checking during routine health visits.

One principle makes sense regardless of the schedule: tracking the same meaningful markers over time can be more informative than chasing a new longevity score every few months.

Trends tell a story that a single result cannot.

Final Words

Longevity testing sounds futuristic, but the most useful information can still come from fairly familiar blood tests. NAD+ testing adds an interesting window into cellular metabolism, yet the latest human evidence suggests that a single blood NAD+ number should not be used as an aging score.

If supporting NAD+ metabolism is already part of your healthy-aging routine, Omre NMN + Resveratrol combines NMN, an NAD+ precursor, with resveratrol in a research-led formula. 

Supplements can complement healthy habits, but they should not replace medical testing, exercise, sleep, nutrition, or advice from your healthcare professional.

FAQs

Can you test NAD levels?

Yes. Specialized laboratories can measure NAD+ in blood and other biological samples. However, NAD+ testing is not as standardized or clinically established as tests such as glucose, HbA1c, or cholesterol.

What is a good NAD level?

There is no universally accepted NAD+ level that defines healthy aging. A study of 1,518 adults reported an average whole-blood NAD+ concentration of about 33.0 μmol/L, but results differed between groups and should not be treated as a universal target. (2)

Can a blood test tell your biological age?

Some tests estimate biological age using blood biomarkers, DNA methylation, or other biological measurements. However, researchers have not agreed on one gold-standard method. (4)

What blood tests are best for longevity?

Tests that assess cardiovascular, metabolic, kidney, liver, and inflammatory health tend to provide the most established clinical information. Examples include ApoB, HbA1c, glucose, lipids, kidney function, liver enzymes, and hs-CRP.

Is NAD testing worth it?

It may be interesting if you want to track NAD+ itself, particularly in a research or specialized health setting. It should not be treated as a standalone test of longevity or biological age.

References

1. Human whole-blood NAD+ levels do not vary with age or lifestyle interventions, Nature Metabolism, 2026

2. Association of human whole blood NAD+ contents with aging, 2022

3. DunedinPACE, a DNA methylation biomarker of the pace of aging, 2022

4. Methods for the assessment of biological age: A systematic review, 2025