NAD+: The Levels Go Up. The Question Is What Follows.

What is NAD+?

NAD+ is not a peptide and does not belong to the same family as anything else in this library. It is a coenzyme, present in every cell, and it does two jobs that matter here.

The first is energy. NAD+ carries electrons through the reactions that convert food into ATP, which makes it a hard requirement rather than an optimisation.

The second is repair. Sirtuins and PARP enzymes, which maintain DNA and regulate how genes are expressed, consume NAD+ to do their work. When NAD+ is scarce, those systems compete with energy production for what is left.

Levels fall with age. That decline is the entire basis of the interest, and it is also why supplementing precursors is a plausible idea rather than a marketing invention. Regenerative Resilience covers it at pp. 158–163 and The Longevity Map at pp. 66–68.

What does the research show?

Safety first, because it is the clearest finding. NR-SAFE, published in Nature Communications in 2023, was a randomised double-blind trial of high-dose nicotinamide riboside (reference 1). Trials of this class have generally found it well tolerated.

Cognition and ageing. A randomised placebo-controlled trial of NR in older adults with mild cognitive impairment was published in GeroScience in 2024 (reference 2), and a phase-II randomised pilot in older adults appeared in Alzheimer’s & Dementia in 2026 (reference 3). These are genuine trials in the population that matters, and they measured real if undramatic effects — which is the normal shape of early clinical work in healthy ageing.

Where a signal is clearer. A 2025 double-blind trial in Aging Cell studied nicotinamide riboside in patients with Werner syndrome, a genetic condition of accelerated ageing (reference 4). Conditions with a specific defect are often where a mechanism shows itself first.

Where the evidence stands. Raising NAD+ is established. Translating that into measurable clinical benefit in otherwise healthy people has produced small effects so far, and the clearest results come from populations with a particular deficit — which is often where a mechanism shows itself first. That is the current state of the field, and it is the reason to read the marketing around this category carefully without dismissing the biology.

Is NAD+ legal or FDA approved?

Not an approved drug. Neither NAD+ nor its precursors are approved medicines for any indication.

NR and NMN are not in the same regulatory position, which surprises most people. Nicotinamide riboside is sold as a dietary supplement. NMN’s status as a dietary supplement has been contested by the FDA on the grounds that it was investigated as a drug first, which is why its availability has shifted around and why some retailers have pulled it.

Injectable and IV NAD+ sits somewhere else again: it is offered by clinics, and it is not an approved product.

Sport: not named on the 2026 WADA prohibited list.

This page is reviewed and updated as the status changes.

Risk, benefit, and the conversation this page is for

The gap here is between a measurement and an outcome. Raising NAD+ with a precursor works, and the trials agree on it because they measure it directly. What that produces clinically in otherwise healthy people has been modest, with the clearer signals showing up in populations that have a specific deficit. The toxicology has stayed quiet across those trials, so the realistic downside on current evidence is that it delivers less than the marketing promises, not that it does damage. The safety section above carries the one question worth raising specifically.

The regulatory picture is moving, and it is moving one compound at a time. In July 2026 an FDA advisory committee recommended six peptides, BPC-157, TB-500, KPV, MOTS-c, Epitalon and Semax, for the list of bulk substances compounding pharmacies may use. The same committee has turned peptides down and still does: ipamorelin and CJC-1295 sit in Category 2, barred from compounding. The distinction is the useful part. Each compound is being read on its own risk record rather than lumped under one verdict called unapproved.

The clinicians working with these compounds are not fringe, and their reasoning is comparative rather than enthusiastic. The approved options for chronic inflammation and slow-healing tissue carry burdens that are thoroughly documented: long-term anti-inflammatories on the gut and kidneys, repeated corticosteroid injections on connective tissue, glucose control and bone. Weighed against that, a compound with a quiet toxicology record and an incomplete efficacy record is a reasonable thing to discuss. It is not a reasonable thing to promise, and that is the line this page tries to hold.

Which is the point of the series. Nothing here is a recommendation to use NAD+. People misuse approved medicines and unapproved compounds alike, and that is neither the purpose nor the intent of this page. The point is a better conversation than the internet usually allows: with a clinician who knows your history, your labs and everything else you take, and who can help build a plan that fits you.

Where NAD+ appears in our books

This page is the plain-language overview. The books go further: mechanism detail, evidence tiers, how NAD+ fits a full protocol, and the cautions that go with it. Page numbers refer to the print editions.

Books marked Look Inside include these exact pages in their free preview.

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