NAD Level Test

NAD is the molecule your cells use to turn food into usable energy and to repair DNA. Levels are widely discussed and rarely measured.

This test measures how much of it is in your blood, from a finger-prick dried blood spot you take at home, and places the figure against a reference range matched to your age and sex.

What you get is one figure: total NAD in capillary blood, in micromoles per litre, measured by enzymatic cyclic assay on a dried blood spot.

We say that plainly because some marketing in this field implies more. The test does not report NAD⁺ and NADH separately, and it does not give you a redox ratio between them. It gives you one well-measured number, against a reference range built from a study of 1,068 people, narrowed to those meeting health-based exclusion criteria, then split by age and sex.

Your result falls into one of five bands, from low through optimal to elevated. Both ends are worth knowing about. Low NAD is the one people expect. An elevated result matters too, and often reflects heavy supplementation rather than anything else.

What's in the box

• Finger-prick lancets and a dried blood spot card

• Step-by-step collection instructions

• Pre-paid return packaging

• Your result with the age and sex matched reference range and band

Is this right for me?

Worth doing if

• You are taking NMN, NR or another NAD precursor and want to know whether it is moving the number

• You want a baseline before starting one

• You are generally well and curious about a measurement rather than a claim

Something else should come first if

• You have persistent tiredness, breathlessness, dizziness or unexplained weight loss. See a GP and get a proper set of blood tests. Fatigue has many common causes worth excluding first, and this test will not find any of them.

What this test is, and what it is not

The NAD Level Test is a wellness test, not a diagnostic one.

It does not diagnose any condition, it does not explain fatigue, and it is not a measure of biological age or of how long you will live, whatever the wider marketing in this field suggests.

There is no established clinical target for blood NAD and no evidence that moving your number changes a health outcome. What the test gives you is a measurement against a population reference range — useful if you are already supplementing and want to see whether anything is happening, and not much use otherwise.

Your GP is unlikely to act on the result, and that is not a criticism of your GP. It is not a test used in NHS practice.

Questions

Does it measure NAD⁺ and NADH separately?

No. It reports total NAD, combining both forms. It does not give a redox ratio. We would rather be clear about that than let the name imply more.

What is a good result?

One that falls in the optimal band for your age and sex. There is no evidence-based target beyond that, and higher is not automatically better — elevated results usually reflect heavy supplementation.

Will my GP act on this?

Probably not. It is not a test used in NHS practice and there is no established clinical action tied to the result. If you feel unwell, see your GP for standard blood tests rather than bringing this.

I take NMN. Should I stop before testing?

No. If you want to know what your supplement is doing, test while taking it as usual. If you want an untreated baseline, that is a different question and means stopping for several weeks first.

How should I collect the sample?

Warm hands, a firm finger-prick, and let large drops fall onto the card rather than smearing. Fill every circle and let it dry fully before sealing.