Half the longevity internet will tell you to "test your NAD+ levels" and track them like a number on a standard blood panel. The evidence is more careful. You can measure NAD+ in blood — researchers do it in clinical trials using specialized lab assays — but there is no standardized, validated at-home or routine clinical NAD+ blood test sold to consumers, no agreed-upon "normal range" to compare yourself against, and no proven link between a single NAD+ number and how you feel or age. Right now, measuring NAD+ is a research tool, not a personal diagnostic.
Key takeaways
- NAD+ can be measured in blood and tissue, but only with specialized lab methods used in research — not a test you can reliably order for yourself.
- There is no FDA-cleared consumer NAD+ blood test with a validated reference range, and no established "healthy" number to aim for.
- In trials, NAD+ precursors increased blood NAD+ — but that group-level finding doesn't translate into a meaningful personal readout.
- For now, consistency, sensible dosing, and a transparent, third-party-tested product matter more than chasing a number.
Can you actually measure NAD+ in blood?
Yes — in a laboratory. NAD+ (nicotinamide adenine dinucleotide) is present in blood and in every tissue, and researchers quantify it using sensitive techniques such as liquid chromatography–mass spectrometry and enzymatic assays. These are the methods behind the headlines you read about NAD+ "declining with age" or "rising with supplementation." They are precise, but they are also expensive, technically demanding, and run in controlled research settings — not the kind of turnkey panel your primary-care lab hands you at a checkup.
The clinical trials in this field make the point. A 2018 randomized, placebo-controlled trial found that the NAD+ precursor nicotinamide riboside was well tolerated and increased blood NAD+ by roughly 60% in healthy middle-aged and older adults — a number that only exists because the researchers drew blood and measured it in the lab. A separate 2023 dose-finding trial in 80 healthy middle-aged adults measured blood NAD+ concentrations directly to show that NMN increased them in a dose-dependent way. In other words, NAD+ is measurable — when a research team with the right equipment does the measuring.
Is there a NAD+ blood test I can buy?
Not in any standardized, validated sense. A handful of specialty labs and direct-to-consumer kits have marketed NAD+ or "NAD" testing, but the category has real problems: there is no FDA-cleared consumer NAD+ blood test, no agreed reference range, and little standardization between methods, so two labs can return numbers that aren't comparable. Results also depend on exactly what is measured — whole blood, plasma, or the NAD+ inside specific cells — which are not the same thing.
There is also a practical catch that trips up even good labs: NAD+ is chemically unstable and begins to break down quickly once blood is drawn, so a sample has to be collected, chilled, and processed carefully or the reading drifts. That fragility is one reason NAD+ measurement has stayed in the research world rather than becoming a routine test. If you have seen a slick "know your NAD+ age" offer, treat the precision it implies with healthy skepticism.
What would a NAD+ number even tell you?
Less than the marketing suggests. Even if you got a clean, accurate NAD+ reading, there is no validated target to compare it against and no established relationship between one person's blood NAD+ level and their health, energy, or rate of aging. Levels vary by tissue, by time of day, and by assay, so a single figure is hard to interpret on its own.
The trial data illustrate the gap. In the 2023 NMN study, the strongest signal on both blood NAD+ and a six-minute walking test appeared around 600 mg per day — but that is an average across a group in a 60-day, industry-funded study, not a personal diagnostic you can act on. A 2026 review of targeted supplementation for healthy aging is careful in the same way, describing NAD+ precursors as potential rather than proven tools whose benefits are still emerging and vary between people. Knowing a trial moved a biomarker is not the same as knowing your own number means anything for you.
Better questions than "what's my number?"
If a validated NAD+ test isn't available, what is actually useful? For most people, the productive questions are about the routine, not the readout: Are you taking a disclosed, sensibly dosed form? Is the product third-party tested with a certificate you can verify? Are you consistent over months rather than chasing a quick change? Those are the inputs you can control, and they matter more right now than a number no one can yet interpret for you. If you want a simple, no-blood starting point for thinking about your cellular-health habits, our free Cellular Age Check is a 2-minute self-assessment: take the free Cellular Age Check →.
What we know — and what we don't
What we know: NAD+ can be quantified in blood and tissue with laboratory assays; those assays are how trials show NAD+ precursors like NMN and nicotinamide riboside increase blood NAD+; and NAD+ appears to decline in many tissues with age, at least in animal models.
What we don't know: whether any single person's blood NAD+ level predicts their health or how they age; what a "normal" or "optimal" number would be; and whether tracking NAD+ over time changes any decision worth making. The consumer testing has run ahead of the science that would make it meaningful.
What a NAD+ test will not do
To keep this honest: a NAD+ test — even a good one — is not a medical test, will not reveal your "biological age," will not prove whether a supplement is "working" for you, and will not replace a conversation with your own clinician. Anyone selling a NAD+ number as a verdict on your health is offering more certainty than the science currently supports. If you are considering testing or supplementing for a specific health concern, talk to your clinician first.
Where CELLSHE fits
We build supplements for people who want an evidence-informed, anti-hype routine — not a number to obsess over. Our NAD+ → is formulated to support the NAD+ pathway and cellular metabolism,* and pairs an antioxidant and polyphenol approach with cellular vitality and resilience,* alongside third-party testing you can verify. The evidence behind NAD+ support is still early, so we frame these as studied directions, not guarantees. We don't promise it will move a lab value you can check at home, because that test doesn't meaningfully exist yet — we promise a clean, honestly labeled product and the context to decide for yourself. If you want the bigger picture, our guide to NAD+ supplements: what actually works → and our explainer on what NAD+ is and how it works → are the honest places to start; and if you're weighing the two most common precursors, our NMN vs NR comparison → breaks down the difference.
Frequently asked questions
Can you test your NAD+ levels at home?
There is no standardized, validated at-home NAD+ blood test with an established reference range. Some direct-to-consumer kits exist, but methods aren't standardized and NAD+ degrades quickly after a sample is taken, so results are hard to interpret and compare.
How do researchers measure NAD+?
In studies, NAD+ is measured with sensitive laboratory techniques such as liquid chromatography–mass spectrometry or enzymatic assays, on carefully handled blood or tissue samples. These methods are precise but require specialized equipment and controlled sample handling.
Is there a normal or optimal NAD+ level?
Not one that has been validated for individuals. NAD+ varies by tissue, time of day, and assay, and no agreed reference range or personal target has been established, which is why a single number is difficult to interpret.
Does a higher NAD+ level mean better health?
There is no proven link between one person's blood NAD+ level and their health or rate of aging. Trials show precursors can increase blood NAD+ on average, but a higher reading has not been shown to translate into a specific benefit for you.
Should I get my NAD+ tested before taking a supplement?
A NAD+ test isn't a reliable way to guide that decision today, since there is no validated consumer test or target. If you are considering a supplement for a specific health reason, talk to your clinician rather than relying on a number.
References
- Martens CR, et al. (2018). Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications 9:1286. PMID: 29599478. pubmed.ncbi.nlm.nih.gov/29599478
- Elhassan YS, et al. (2019). Nicotinamide riboside augments the aged human skeletal muscle NAD+ metabolome. Cell Reports 28(7):1717–1728. PMID: 31412242. pubmed.ncbi.nlm.nih.gov/31412242
- Yi L, et al. (2023). The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, dose-dependent clinical trial. GeroScience 45(1):29–43. PMID: 36482258. pubmed.ncbi.nlm.nih.gov/36482258
- Kurtz JA, et al. (2026). Targeted supplementation and nutritional strategies for healthy aging: a review of physiological and molecular benefits. Current Nutrition Reports. PMID: 42234350. pubmed.ncbi.nlm.nih.gov/42234350
