The NAD+ Question Nobody's Asking (But Should Be)
•Posted on May 29 2026
I've lost count of the number of times a practitioner or a well-read client has asked me some version of this: "If you're serious about NAD+ restoration, why aren't you using NMN or NR? Niacinamide is the slowest precursor in the pathway."
It's a reasonable question. And five years ago, I might have agreed with the premise. The precursor speed hierarchy — NR converts faster than niacinamide, NMN sits one enzymatic step closer to NAD+ than NR — is technically accurate when tested in young, healthy cells with fully functioning enzymes.
But here's what nobody in the NAD+ industry seems to want to talk about: the speed of your precursor is almost irrelevant if the system it's entering is broken. And in an ageing body, the system is broken in at least three distinct ways — none of which a faster precursor fixes.
The question the industry keeps asking is "which precursor is fastest?" The question they should be asking is "why is NAD+ declining in the first place — and can we fix that?"
That second question led us to build Re:NRG (previously announced as NAD+ Next Gen). And it's why the formula looks nothing like anything else on the market.
What's Actually Going Wrong With NAD+
NAD+ doesn't decline with age because you run out of precursor material. If it did, the solution really would be as simple as taking more NMN. But the research tells a very different story — one involving at least three simultaneous failures that no single-ingredient supplement can address.
The Factory Floor Problem
The NAD+ salvage pathway is your body's primary NAD+ recycling system. At the heart of it sits NAMPT — nicotinamide phosphoribosyltransferase — the rate-limiting enzyme that converts niacinamide back into NMN and then into NAD+. NAMPT determines the speed limit of the entire pathway.
NAMPT activity drops with age. Measurably, consistently, significantly.
This means it doesn't matter how fast your precursor converts on paper — if NAMPT can't keep up, the cell can't process the input. Flooding NR or NMN into a system with impaired NAMPT is like dumping raw materials onto a factory floor where the assembly line has slowed to a crawl. Output doesn't increase. The materials pile up. And that pile-up triggers the next problem.
The Methyl Donor Drain
When NAD+ precursors accumulate faster than NAMPT can process them, the cell activates a clearance pathway. An enzyme called NNMT — nicotinamide N-methyltransferase — methylates the surplus nicotinamide, diverting it out of the salvage pathway and excreting it. That sounds harmless until you look at what NNMT uses as its methyl donor: SAMe, S-adenosylmethionine.
SAMe isn't a minor player in cellular metabolism. It's the universal methyl donor — the molecule your body uses for DNA repair and methylation, epigenetic regulation (turning genes on and off), neurotransmitter synthesis (serotonin, dopamine, norepinephrine), phase II liver detoxification, and cardiovascular protection via homocysteine metabolism.
The Drain That Gets Bigger With Age
The third failure is arguably the most important, and it's the one the precursor market almost entirely ignores.
Research from Dr Eduardo Chini's group at the Mayo Clinic identified CD38 as the dominant NAD+-consuming enzyme in the human body. CD38 isn't a minor player — it degrades more NAD+ than sirtuins and PARPs combined. And here's what makes it devastating: CD38 expression increases several-fold with age, driven directly by chronic inflammatory cytokines released by senescent cells.
The implication is stark. The older and more inflamed you are, the faster CD38 chews through your NAD+ — no matter how much precursor you take. As researchers in this field have observed, dysfunctional cells consume NAD+ even more aggressively than healthy ones. If you flood precursor into a system dominated by CD38 without suppressing the enzyme, you're not restoring youthful NAD+ levels. You're feeding the largest drain on the system.
This creates a vicious feedback loop: inflammation drives CD38 upward, CD38 depletes NAD+, low NAD+ impairs the repair mechanisms that would clear senescent cells, and the resulting cellular dysfunction produces more inflammation. A faster precursor doesn't break this cycle. It doesn't even touch it.
Why Peter Attia Is Right — About Precursor-Only Approaches
Peter Attia classifies NAD+ precursor supplementation as "noise" for geroprotection. He doesn't take NMN, NR, or NAD+ infusions. A lot of the NAD+ industry dismisses this, but I think Attia is asking the right question: is NAD+ decline causal, or is something upstream driving it?
His scepticism is completely justified — for precursor-only strategies. If all you're doing is pouring more substrate into a system where the recycling enzyme is failing, the dominant drain is accelerating, and the overflow is depleting your methyl donors, then yes — that is noise.
But Attia's critique doesn't apply to an intervention that addresses all three of those failures at once. That's a fundamentally different approach, and it's exactly what Re:NRG was designed to be.
Inside the Formula: Seven Ingredients, Three Levers
Re:NRG contains seven ingredients. Each targets a specific failure mechanism in the NAD+ ecosystem. None are filler. None are there for marketing. Here's what each one does, and why the formula wouldn't work without it.
NMN (Uthever®) — The Direct Precursor
NMN (Uthever®) is a direct NAD+ precursor that enters the salvage pathway one step from NAD+.
Niacinamide — The Foundation
Niacinamide is the precursor — the substrate that enters the salvage pathway via NAMPT and gets recycled into NAD+. On its own, in an aged cell, it would be exactly what the critics say: slow and inefficient. But niacinamide was never meant to carry this formula alone. It's the raw material for a pathway that the other six ingredients restore and protect.
What niacinamide contributes beyond precursor function is significant. It has decades of established human safety data across multiple clinical contexts. It produces no flushing (unlike nicotinic acid). It creates no methylation burden in MTHFR-compromised individuals. Niacinamide and NMN enter the salvage loop at different points: niacinamide upstream of NAMPT, NMN one step from NAD+. That's why Re:NRG uses both.
When the salvage pathway is restored by the rest of the formula, niacinamide delivers sustained, efficient NAD+ recycling. Not a spike and crash — ongoing intracellular maintenance. That's what an ageing body actually needs.
Quercetin (95%) — Three Jobs, One Molecule
Quercetin is the most multi-functional ingredient in the formula, and the 95% standardisation matters — it ensures you're getting standardised potency, not the diluted quercetin found in commodity supplements.
Quercetin does three things simultaneously. It inhibits CD38, directly reducing the dominant enzymatic drain on cellular NAD+. It upregulates NAMPT expression through AMPK-dependent transcription, actively restoring the rate-limiting salvage pathway enzyme that declines with age. And it activates both AMPK and SIRT1 — the cellular maintenance and longevity signalling pathways that caloric restriction and exercise trigger.
Think about what that means within the formula's architecture. Quercetin blocks the biggest drain on NAD+, restores the machinery that produces it, and switches on the longevity pathways that use it. It connects every part of the system — production, protection, and utilisation — in a single compound.
Rutin — Reinforcing the Rate-Limiting Step
NAMPT is the single most important enzyme in the entire NAD+ salvage pathway. If it fails, nothing downstream works properly — regardless of which precursor you use. Given how critical NAMPT is, relying on a single activating compound felt like an unnecessary risk.
Rutin is a Sophora japonica flavonoid that drives NAMPT upregulation alongside quercetin, working through AMPK-dependent mechanisms via a related but distinct molecular interaction. Two activators on the most critical enzyme in the pathway provide more resilient and sustained upregulation than one alone — especially in individuals with significant age-related NAMPT decline.
Rutin also contributes independent anti-inflammatory and vascular support properties. In a formula where reducing systemic inflammation is part of the broader strategy for protecting NAD+ from CD38, every compound that supports the anti-inflammatory architecture earns its inclusion.
Apigenin — Dual Coverage on the Biggest Drain
CD38 expression can ramp up dramatically in aged, inflamed systems — driven by multiple inflammatory signalling cascades originating from senescent cells. Relying on a single CD38 inhibitor carries a real risk: if inflammatory signalling overwhelms that one compound's capacity, you lose suppression at the most critical point in the entire formula.
Apigenin provides the second arm of dual CD38 inhibition. Together with quercetin, it delivers more comprehensive and robust suppression of the enzyme consuming more NAD+ than any other in the body. Two inhibitors, two distinct molecular interactions, one target — the kind of redundancy that serious formulation requires when the target is this important.
Beyond CD38 inhibition, apigenin has documented effects on cellular senescence pathways, contributing additional value to the formula's anti-ageing architecture.
EGCG (Green Tea Extract) — Supporting Activity
EGCG, a green tea polyphenol, adds supporting activity alongside resveratrol.
EGCG's second role in the formula is supporting mitochondrial biogenesis — the generation of new mitochondria. This matters because mitochondria are both the primary consumers of NAD+ for ATP production and the organelles most damaged when NAD+-dependent repair declines. Restoring NAD+ without supporting the mitochondria that use it is only half the job. EGCG ensures the formula addresses both — more NAD+ and healthier mitochondria to put it to work.
Trans-Resveratrol — Activating What NAD+ Is Actually For
Restored NAD+ levels are only valuable if the enzymes that depend on NAD+ are activated to use it. SIRT1 — the most extensively studied longevity sirtuin — requires NAD+ as a co-substrate for every deacetylation reaction it performs. Without NAD+, SIRT1 can't function. But without SIRT1 activation, a restored NAD+ pool sits underutilised.
Trans-resveratrol directly activates SIRT1, creating a deliberate synergistic loop: the rest of the formula restores NAD+, and resveratrol ensures SIRT1 is primed to use it for cellular maintenance, DNA repair, metabolic regulation, and stress resistance.
Resveratrol also activates AMPK and supports mitochondrial biogenesis — working alongside EGCG to drive mitochondrial renewal from two complementary angles. The combination means Re:NRG doesn't just increase NAD+ levels. It increases the cellular capacity to convert that NAD+ into functional longevity benefits.
The System, Not the Parts
It's worth stepping back from the ingredients to see the architecture, because the architecture is the point.
The salvage pathway is restored (quercetin + rutin driving NAMPT upregulation). The precursor feeds into functioning machinery (niacinamide entering a restored pathway). The dominant drain is suppressed (apigenin + quercetin providing dual CD38 inhibition). EGCG, a green tea polyphenol, adds supporting activity alongside resveratrol. And the longevity signalling that NAD+ fuels — SIRT1, AMPK, mitochondrial biogenesis — is activated (trans-resveratrol + EGCG + quercetin) so the restored NAD+ pool actually drives cellular repair and maintenance.
No single ingredient produces this outcome. No precursor-only supplement touches most of these pathways. It's the coordinated action of all seven — the system — that makes the formula work.
Re:NRG and Re:juvenate Pro
Re:NRG stands on its own. You don't need anything else to start it. Re:juvenate Pro works on different systems, immune and gut, so if you already take it, the two pair well. Start with whichever fits where you are.
The Real Question
The NAD+ market will keep competing on precursor speed. Companies will keep launching the next NMN variant, the next NR formulation, the next single-ingredient product promising higher NAD+ levels faster.
We chose not to enter that race — because the evidence told us it was the wrong race.
NAD+ decline in ageing is not a precursor deficiency. It's a systems failure: enzymatic impairment, inflammatory drain, methylation diversion, mitochondrial decline, and reduced longevity signalling, all compounding simultaneously. You don't fix a systems failure with a faster ingredient. You fix it by restoring the system.
Seven ingredients working across three levers: precursor supply, protecting NAD+ from CD38, and sirtuin support. Every one essential. That's what Re:NRG is — and that's why it works.