Nicotinamide Riboside (NR)
Also known as: NR, Niagen, nicotinamide riboside chloride.
Ethanol metabolism consumes NAD⁺ at both the ADH and ALDH2 steps, crashing the NAD⁺/NADH ratio. NR raises NAD⁺ via the salvage pathway (NR → NMN → NAD⁺) with the cleanest human PK data of the precursors. Without restored NAD⁺, ALDH2 throttles even when enzyme is abundant; gluconeogenesis stalls; SIRT3 — which deacetylates and activates ALDH2 — loses its substrate. Tier 1 because this is the cofactor side of the same enzymatic clearance pathway L-cysteine cannot rescue at supplement doses.
Where this fits in the system
What it does
Ethanol metabolism burns through NAD⁺ — the cofactor your liver uses to oxidize alcohol to acetaldehyde and then acetaldehyde to acetate. NR raises the NAD⁺ pool through the salvage pathway, restoring the cofactor that ALDH2, SIRT3, and the TCA cycle all depend on. Without it, the enzymatic clearance you nominally have is throttled at the cofactor step.
How it works
The mechanism
Each step of ethanol oxidation reduces NAD⁺ to NADH. ADH at the first step, ALDH2 at the second. Two doses of cofactor consumption per molecule of ethanol. The NAD⁺/NADH ratio in liver mitochondria collapses within the first hour of drinking and stays collapsed long after the last drink.
The downstream consequences are the morning. Gluconeogenesis stalls because it needs NAD⁺ at multiple steps — that's the hypoglycemia and the wired-but-empty feeling. The TCA cycle slows. SIRT3, an NAD⁺-dependent deacetylase that activates mitochondrial ALDH2, runs out of substrate — so even ALDH2 enzyme that is physically present is not catalytically maximal.
NR is a salvage-pathway precursor: NR → NMN → NAD⁺. It bypasses the slow de novo tryptophan path and the rate-limited NAMPT step that limits niacin-based repletion. Trammell 2016 established the human pharmacokinetic profile; Conze 2019 and Martens 2018 confirmed sustained whole-blood NAD⁺ elevation at 300–1000 mg doses.
Buying guidance
Tru Niagen 300 mg or another nicotinamide riboside chloride product. NMN at the same molar dose is an acceptable substitute, but NR has the cleaner human pharmacokinetic dataset and the longer safety record at the doses used here. Avoid generic "niacin" or "nicotinamide" — both are NAD⁺ precursors but with markedly less efficient repletion at the salvage step that matters here.
Take with food when possible. Skip the Nightcap dose: NR can be mildly activating at higher single doses and the protocol prioritizes uninterrupted sleep over additional cofactor topping-up in the middle of the night.
Deep science · Nicotinamide Riboside — deep dive
Why NR over NAD⁺ itself
Oral NAD⁺ is largely degraded in the gut and on first pass; circulating NAD⁺ does not freely cross cell membranes. The body builds NAD⁺ inside cells from precursors. NR is taken up by cells via the equilibrative nucleoside transporters and converted to NMN by NRK1/NRK2, then to NAD⁺ by NMNAT. That two-step intracellular conversion is what gives NR its measurable plasma-NAD⁺ rise where direct NAD⁺ supplementation does not.
SIRT3 and ALDH2
ALDH2 is regulated post-translationally by acetylation on lysine residues; acetylation suppresses activity. SIRT3 — an NAD⁺-dependent mitochondrial deacetylase — removes those marks and restores activity. So NAD⁺ availability acts on ALDH2 in two distinct ways: as the direct catalytic cofactor and as the substrate for the deacetylase that keeps the enzyme tuned. Both require NAD⁺ regeneration.
The Conze 2019 trial
A double-blind RCT (Conze et al., Sci Rep 2019) at 100, 300, and 1000 mg/day demonstrated dose-responsive whole-blood NAD⁺ elevation over eight weeks with no adverse safety signal. Trammell 2016 (Nat Commun) established acute pharmacokinetics: a single 300 mg dose roughly doubles whole-blood NAD⁺ within ~8 hours. Martens 2018 (Nat Commun) confirmed safety at 1000 mg/day for six weeks in older adults.
Why the Mayday dose doubles
Mayday is the salvage scenario — NAD⁺ pools are most depleted, gluconeogenesis is most impaired, and SIRT3-mediated ALDH2 reactivation matters most for clearing the residual aldehyde load. 600 mg lands well within the established human safety envelope and produces the steepest plasma NAD⁺ response in the published dose-response curves.
Layer interaction
NR works upstream of nearly every other Tier 1 lever in the protocol. Sulforaphane's Nrf2-mediated ALDH2 induction needs NAD⁺ for the enzyme to actually catalyze. NAC's glutathione restoration is downstream of redox balance, which NAD⁺/NADH controls. Electrolytes handle the water-and-sodium side; NR handles the cofactor side. The two together are the protocol's spine.