Comprehensive assessment of cellular NAD+ metabolism from a dried blood spot. Six analytes measured by LC-MS/MS, yielding a composite Niacin Number reflecting mitochondrial function and metabolic resilience.
6 analytes + composite index
3–5 working days
The NAD+ Index is a comprehensive panel that quantifies the key molecules of NAD+ metabolism from a single dried blood spot. It measures both oxidised and reduced forms of the two principal nicotinamide coenzymes (NAD+ / NADH and NADP+ / NADPH), along with two vitamin B3 precursors (nicotinamide and nicotinic acid), producing a composite Niacin Number that reflects overall cellular energy status.
Clinical indications include:
| Analyte | Role | Clinical Significance |
|---|---|---|
| NAD+ | Nicotinamide adenine dinucleotide (oxidised) | Central coenzyme in catabolic energy metabolism; electron carrier in mitochondrial respiration |
| NADH | Reduced NAD+ | Delivers electrons to the electron transport chain for ATP production; elevated levels may indicate metabolic bottleneck |
| NADP+ | Nicotinamide adenine dinucleotide phosphate (oxidised) | Coenzyme in anabolic biosynthetic pathways including fatty acid and cholesterol synthesis |
| NADPH | Reduced NADP+ | Essential for glutathione regeneration, antioxidant defence, and reductive biosynthesis |
| Nicotinamide (NAM) | Vitamin B3 form; NAD+ precursor (salvage pathway) | Elevated levels may indicate recent B3 supplementation; very high levels may inhibit sirtuin activity |
| Nicotinic Acid (NA) | Niacin; NAD+ precursor (Preiss–Handler pathway) | Found in meat, fish, and fortified foods; supports NAD+ synthesis via an alternative biosynthetic route |
The Niacin Number (NAD/NADP Index) is a composite score calculated as (NAD+/NADH × NADP+/NADPH) × 100. This integrates the catabolic (energy production) and anabolic (biosynthetic) redox systems into a single metric reflecting overall NAD+ metabolic health. The optimal range is 90–350.
Nicotinamide adenine dinucleotide (NAD+) is one of the most important molecules in human biology. Present in every living cell, it serves as a critical coenzyme in over 500 enzymatic reactions, functioning as an electron carrier in mitochondrial energy production and as a co-substrate for key regulatory enzymes including sirtuins, PARPs, and CD38.
NAD+ participates in over 500 enzymatic reactions across all major metabolic pathways
Tissue NAD+ levels decline significantly with age, contributing to metabolic dysfunction
PARP enzymes consume NAD+ during DNA repair; chronic damage accelerates depletion
In its role as an electron shuttle, NAD+ accepts electrons during glycolysis and the citric acid cycle (becoming NADH), which then delivers them to the mitochondrial electron transport chain to drive ATP synthesis. This redox cycling between NAD+ and NADH is fundamental to cellular energy production, and the NAD+/NADH ratio serves as a key indicator of catabolic metabolic health.
The phosphorylated counterpart, NADP+/NADPH, operates in parallel but supports anabolic processes — fatty acid synthesis, cholesterol biosynthesis, and critically, the regeneration of glutathione, the cell's primary antioxidant defence molecule. The balance between these two redox couples provides a comprehensive picture of cellular metabolic function.
NAD+ levels decline with age through multiple mechanisms: increased consumption by CD38 (an enzyme upregulated by chronic inflammation), increased PARP activation due to accumulated DNA damage, and reduced biosynthetic capacity. This decline has been implicated in mitochondrial dysfunction, metabolic disease, neurodegeneration, and accelerated ageing. Restoring NAD+ levels through precursor supplementation (NMN, NR, niacin) has emerged as a major area of longevity and metabolic research.
NAD+ levels decline with age, making age-stratified interpretation essential for meaningful results. Key points to understand about NAD+ reference ranges:
As NAD+ testing is a relatively new clinical biomarker, reference ranges are continually being refined. Your report includes percentile-based interpretation against our tested population.
NAD+ is one of the most important molecules in human biology — essential for energy production, DNA repair, and cellular signalling. Testing is particularly relevant for:
Declining NAD+ is one of the hallmarks of ageing, but research shows it can be meaningfully increased through targeted strategies:
Re-test your NAD+ index after 8–12 weeks of intervention to objectively measure the impact of supplementation or lifestyle changes.
All six analytes are measured simultaneously from a single DBS sample using liquid chromatography with tandem mass spectrometry (LC-MS/MS), the gold standard method for NAD+ biomarker measurement. Isotope-labelled internal standards are employed for each analyte to ensure accurate and reproducible quantification across the full dynamic range.
LC-MS/MS provides the sensitivity and specificity required to resolve structurally similar nicotinamide coenzymes (NAD+, NADH, NADP+, NADPH) within a single chromatographic run, while simultaneously quantifying the B3 precursors nicotinamide and nicotinic acid. The Niacin Number composite score is calculated from the measured ratios.
The DBS format enables convenient home collection for longitudinal NAD+ monitoring, making it well suited for supplementation tracking and ageing research. Samples are stable at ambient temperature during postal transit.
From enquiry to results in a few simple steps — no clinic visit required.
This test is available to healthcare professionals, wellness brands, clinics, and research institutions worldwide. We currently serve partners in:
Whether you need testing services for your patients, white-label kits for your brand, or method transfer to your own laboratory — get in touch to discuss how we can work together.
The NAD+ index is a comprehensive panel that measures NAD+, NADH, NADP+, NADPH, and the vitamin B3 precursors nicotinamide and nicotinic acid from a single dried blood spot. These six analytes reflect cellular energy production and mitochondrial function. NAD+ is essential for over 500 enzymatic reactions in the body, and the composite Niacin Number calculated from the results provides a single metric of overall NAD+ metabolic health.
NAD+ levels decline significantly with age, driven by increased consumption from CD38 and PARP enzymes, and reduced biosynthetic capacity. This decline is linked to mitochondrial dysfunction, impaired DNA repair, and cellular senescence. Testing reveals your baseline NAD+ status before starting supplementation, allowing you to measure whether interventions like NMN or NR are actually restoring your levels.
The test uses a simple finger-prick to collect a few drops of blood onto a dried blood spot (DBS) card. You can do this at home or in a clinic — no venous blood draw is needed. The DBS card is stable at room temperature and can be posted to our laboratory by regular mail from anywhere in the world.
Results are typically delivered within 3 to 5 working days from the time your sample arrives at our laboratory. The analysis is performed by LC-MS/MS (liquid chromatography-tandem mass spectrometry), which provides highly accurate quantification of all six NAD+ metabolites simultaneously.
NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are the most common NAD+ precursors used in supplementation. Niacin and nicotinamide are also effective but may have different side effect profiles. Testing before and after a supplementation period allows you to track your response objectively rather than relying on subjective improvements alone.
Masdiag's NAD+ index test is available worldwide through our partner network. We currently serve healthcare professionals, wellness brands, and clinics in Europe, the United Kingdom, Asia, Australia, New Zealand, and the United States. Contact us to discuss testing services, white-label kits, or method transfer to your laboratory.
Whether you need testing services, method transfer, or white-label kit development — we'd love to hear from you.