Overview
Candidacy here is less about a test result than about two things: what has already been ruled out, and what you are expecting.
There is no biomarker that identifies who will respond. NAD+ levels are not routinely measured in clinical practice, there is no established threshold, and no test currently predicts response. So candidacy is assessed from the clinical picture and from whether the groundwork has been done.
| Fits well | Fits poorly |
|---|---|
| A panel has already been run and correctable causes addressed | Fatigue that has never been investigated |
| Realistic expectations, agreed in advance | Expecting a defined, guaranteed result |
| Interested in it as one part of a broader plan | Looking for a single intervention to replace the rest |
| Willing to assess honestly at the end of a course | Committed to continuing regardless of outcome |
| Comfortable with the regulatory position and the cost | Uncertain about either |
| Able to tolerate the infusion sensations | — |
Situations where something else comes first: an untreated thyroid problem, iron depletion, undiagnosed sleep apnea, poorly controlled glucose, depression, or heavy alcohol use. None of these is a reason NAD+ could not be added later — they are things that will dominate the picture until they are addressed, and will make it impossible to tell what anything else did.
Why there is no candidacy test
This surprises people, and it is worth explaining rather than glossing.
NAD+ levels are not routinely measured in clinical practice. Measuring them reliably is technically demanding, blood levels do not straightforwardly reflect tissue levels, and there is no established reference range or threshold defining who is deficient.
So a provider offering to test your NAD+ level and treat accordingly is offering something the science does not currently support. We do not do it, and we would be cautious about anyone who does — not because measurement is a bad idea in principle, but because the interpretation does not exist yet.
What is assessed instead is the clinical picture: what your symptoms are, what has been excluded, what else is going on, and what you are hoping for.
What should be ruled out first
Not because NAD+ is a last resort, but because these are common, checkable and treatable, and because they will otherwise dominate whatever you try next.
Thyroid function. Hypothyroidism peaks in this age group and produces fatigue, weight change, low mood and cold intolerance. Which test does what.
Ferritin. Iron depletion is the most commonly missed cause of midlife fatigue, and ferritin is not on a standard panel. Why it gets missed.
B12 and vitamin D.
Glucose and insulin, because insulin resistance produces afternoon crashes years before glucose moves. Insulin first.
Sleep, including a screen for apnea — common over 45, mostly undiagnosed, and it produces this exact presentation.
Mood and alcohol, both under-asked and both significant.
Hormonal status, in both men and women, where the picture suggests it.
If one of these turns up, correcting it is the highest-yield thing available. If none does, you have a cleaner baseline and anything you try afterward is far easier to interpret.
Who should not have it without further conversation
Some situations need a specific discussion rather than a general one.
Pregnancy or breastfeeding — safety has not been established.
Active cancer, or a history of it. NAD+ is involved in cellular metabolism and DNA repair, which are processes relevant to cancer biology in ways that are not fully characterized. This warrants a conversation with your oncology team rather than a decision made independently.
Significant kidney or liver impairment, which affects how anything administered is handled.
A complex medication regimen, which is worth reviewing before adding anything.
Anyone who has had a reaction to a previous infusion.
And more generally: if you are under the care of a specialist for a significant condition, they should know what you are taking. Treatments obtained outside a primary care relationship frequently do not make it onto the record, and that is a real problem rather than an administrative one.
What to expect if you proceed
The session itself. Infusions produce rate-dependent flushing, nausea, chest tightness and cramping when given quickly. Given slowly, most people are comfortable. Tell whoever is administering it if you feel these — the response is to slow the rate. More on what a session involves.
The timeframe. A course rather than a single session, with an assessment at the end of it rather than after each one.
Individual variation. Responses differ, and there is currently no way to predict yours. Agreeing in advance what you are looking for, and when you will judge it, is what makes the assessment meaningful.
An honest review. If nothing has changed by the end of a course, that is information. More of the same is not automatically the next step.
What we would suggest alongside
Whatever anyone decides about NAD+, these have the largest documented effects on energy and function in this age group and they are worth doing regardless.
Resistance training, which addresses the muscle loss of midlife directly and improves insulin sensitivity independent of weight change.
Sleep, treated as a health intervention rather than a preference, including screening for apnea.
Correcting what the panel finds, which is the highest-yield single action for most people.
Reducing alcohol, which affects sleep, mood and energy simultaneously.
None of that is a substitute for a considered conversation about what else might help. It is the foundation that makes anything else worth assessing.
Frequently asked questions
Who is a good candidate for NAD+ therapy? Someone who has had the common causes of their symptoms checked and addressed, who has realistic and agreed expectations, and who is treating it as one part of a plan rather than the whole of it.
Can I get my NAD+ level tested? Not usefully. NAD+ is not routinely measured clinically, blood levels do not straightforwardly reflect tissue levels, and there is no established threshold or reference range.
Who should avoid it? Anyone pregnant or breastfeeding, anyone with active cancer or a cancer history without oncology input, anyone with significant kidney or liver impairment, and anyone who has reacted to a previous infusion.
What if I have already tried everything? Worth checking what "everything" covered — ferritin, a full thyroid panel and a sleep apnea screen are missed more often than people expect.
How will I know if it helped? By agreeing in advance what you are looking for and when you will judge it, then reviewing honestly at the end of a course.
Where this fits in your plan
Candidacy comes down to sequence: check the common causes, correct what is correctable, then decide what else is worth adding with a clear view of what it involves.
That way the decision is made on your actual picture rather than on a symptom, and whatever you try afterward can be judged properly. What we check, what NAD+ therapy involves here, and what it costs.
We measure first. Then we act.
Diagnostic testing does not diagnose or rule out disease on its own and is interpreted by a licensed provider alongside your history and examination.
Ready to start your second act?
It starts with measuring, not guessing. A short, clinician-reviewed assessment shows what fits you.
This article is educational and is not medical advice. Treatments are available only to eligible patients following clinical evaluation and within applicable regulations. Individual results vary.
