Coach — NAD+ Precursors (The Kit)

Kit page: salvage tickets after the vest. Diet-first; when a precursor is still elected, the essay discusses IR nicotinic acid as information, not a prescription. NR/NMN are not the default recommendation.

The Kit · Sage · Surfer · MB · Fuel · Strength

Few molecules have been marketed as hard in the last decade as NAD+. The pitch is simple and flattering. Levels fall with age, so raise them and you turn back the clock. Shelves fill with nicotinamide mononucleotide and nicotinamide riboside, blood tests promise to show your number rising, and the price climbs with every patent and every celebrity endorsement.

The working hypothesis behind this essay is colder. NAD+ is not the engine. It is closer to a ticket the engine uses to move electrons, and a receipt that the cell's repair enzymes tear each time they spend energy on maintenance. Printing more tickets does not create the traffic. It does not rebuild the folded inner membranes of mitochondria, it does not supply the fuel, and it does not tell a sedentary body living out of step with daylight that it needs to make more energy. In an engine that is already being asked to work, a precursor may relieve a bottleneck. Used first, it is one more attempt to change a reading on the dashboard without changing what the dashboard reports.

What NAD+ actually does

Inside every cell, NAD+ and its partner NADH shuttle the hydrogen and electrons stripped from food into the first complex of the mitochondrial energy chain. A close relative, NADP+, supports building new molecules and recharging the cell's antioxidant defenses. The same oxidized molecule is also spent by three families of maintenance enzymes: the sirtuins, the DNA-repair enzymes called PARPs, and an enzyme on immune cells called CD38. Every one of those maintenance acts uses up a molecule of NAD+ and releases nicotinamide, which the cell then has to recycle.

That recycling is the heart of the story. Most of the body's NAD+ is not made fresh from the amino acid tryptophan. It is salvaged. The everyday route rebuilds NAD+ from nicotinamide through an enzyme called NAMPT, which is the rate-limiting step, costs energy to run, follows a daily clock, and responds to nutrients and demand. Nicotinic acid, the original niacin, takes a separate route through an enzyme called NAPRT. Nicotinamide riboside skips NAMPT through its own kinases. Nicotinamide mononucleotide is the direct product of NAMPT, and researchers still argue about whether it crosses cell membranes intact or must first be converted to riboside.

So the size of the pool at any moment matters less than how fast it turns over. When demand is real and energy is being made and spent quickly, the body makes more NAMPT and the cycle speeds up. When demand is low, inflammation is high, and the repair enzymes keep draining the supply, the pool shrinks. In that reading, falling NAD+ with age is more often a consequence of how the engine is being run than its original cause.

Why the pool falls

The extended report names four causes that interlock. Mitochondrial capacity shrinks and becomes leakier. NAMPT falls in tissues that are inactive, inflamed, and out of step with their daily clock. Consumption by CD38 and the repair enzymes rises. And food quality thins even when calories are abundant. None of these is "the molecule got old." Each is a statement about operating conditions, and each points back toward food, daylight, sleep, and physical load before it points toward a capsule.

This also explains why measuring NAD+ in a blood sample can mislead. Blood levels after an oral precursor are not the same as energy production in muscle, brain, or liver. A test that glows after a supplement shows that the supplement was absorbed. It does not show that capacity has been restored.

The gut decides what the pill becomes

One of the more surprising findings in this field concerns what happens to these supplements before they reach the tissues. Tracer studies and head-to-head comparisons suggest that a large share of oral riboside and mononucleotide is broken down and converted toward nicotinic acid by gut microbes, then delivered to the liver along the nicotinic acid route. Our own cells leak nicotinamide into the gut as well, and the microbes convert it in the same direction.

In other words, part of what a premium precursor delivers is what a healthy gut community, fed a proper human diet, was going to deliver anyway. That is the logic behind the hypothesis's frugality. Boutique prices are not the default, and adding a precursor to a disrupted gut is not a way to add fuel to the fire.

Ranking by mechanism, not by brand

The four common precursors differ in ways that matter. Nicotinamide is the body's everyday currency and is already present in food. At high supplemental doses it can inhibit the very sirtuins people buy precursors to feed, which is the irony of taking it in large amounts. Dermatology has its own separate evidence for it, a different question from this one. Nicotinic acid enters through its own pathway and does not occupy that inhibitory site. Its well-known costs, flushing and a worsening of insulin resistance, belong to the gram-scale pharmacologic amounts and sustained-release forms used in lipid clinics, not to a small immediate-release amount taken with food. Nicotinamide riboside has the cleanest trial record and bypasses NAMPT, which is a genuine distinction when that step is impaired, but it also sits behind an aggressive patent estate, and the hypothesis does not treat it as the default. Nicotinamide mononucleotide raises blood NAD+ about as much as riboside in head-to-head data, with open questions about product quality, and with no good evidence that it reaches tissues better.

What all four share is a limit. None of them rebuilds conductance through the energy chain, restores the membrane fat cardiolipin, or adds mitochondria. None substitutes for the electron-transport support discussed in the essay on methylene blue, for CoQ10, or for the animal-fat membrane lipids discussed under fuel.

Where a precursor would fit, if at all

The order the hypothesis proposes puts any precursor last. Food is the starting point: animal fats and proteins and a working partnership with gut microbes, with the industrial contaminants discussed under fuel toxins kept out. Then daily rhythm, through light, temperature, and meal timing, as set out in the essay on circadian rhythm. Then strength, because muscular work in the active part of the day induces NAMPT without any patent. Then support for electron transport itself. Only after all of that does the question of a supplement arise.

If someone still chooses one after that foundation is in place, the amount the extended report names is 25 mg of immediate-release nicotinic acid. It is stated as information about the hypothesis, not as a prescription, and it is deliberately small: above the dietary reference amount, below the point where many people flush, and far below the lipid-clinic range. It is not sustained-release or timed-release niacin, not the "no-flush" inositol form, not gram amounts of nicotinamide, not the old clinic habit of taking aspirin before niacin to blunt the flush, and not riboside or mononucleotide as the starting point. The extended report also reasons from timing. The NAD+ recycling machinery runs on a daily clock, and in mice a pulse of NAD+ before the active period helped metabolic markers while a pulse before rest inverted the liver's clock. On that reading, the bedtime extended-release niacin convention of lipid clinics points the wrong way. That is a mechanism, not a timetable to follow.

The more important rule is what to do if nothing happens. If grip strength, aerobic capacity, sleep, and metabolic markers do not move once the foundation is in place, the hypothesis says to stop, not to climb toward pharmacologic niacin or switch to a branded nucleoside as if the missing piece were the label. Silence is not a reason to escalate.

Safety and the boundaries of this essay

NAD+ precursors interact with methylation, one-carbon metabolism, and certain drugs, and they are not for unsupervised megadosing. Anyone taking medicines where those interactions matter needs their prescribing physician involved, not a decision made from an essay. A proper human diet already contains niacin equivalents, and a capsule that becomes part of someone's identity is just another dashboard.

How to judge it

The test of any precursor is whether the engine changes. The readouts that matter are the ones that reflect capacity: grip strength, an estimate of aerobic fitness, insulin resistance markers, the normal drop in blood pressure during sleep, and lean mass. A blood NAD+ test that glows while those stay poor is a painted odometer. If a precursor seems to "work" only on the assay, it has not worked.

The extended report is clear about what would weaken its own case. If precursors restored capacity in sedentary, poorly fed people without any change to food, rhythm, or load, the ticket model would be in trouble. So would evidence that a small immediate-release amount of nicotinic acid worsened insulin resistance the way gram-scale doses do. So far, the human record looks mostly like dashboards moving, which is what the model expects if these molecules are salvage tickets.

NAD+ matters enormously. It is simply downstream. Fix the engine, keep it fed, timed, and loaded, and the ticket supply largely takes care of itself. The neighboring essays on aspirin and aging apply the same reasoning to other molecules marketed as shortcuts.

For the full argument, read the extended report on NAD+ precursors. The short version is in the lessons. Talk with your own physician before changing medications or supplements.

A working hypothesis, open to correction and revised as new evidence arrives. Last revised October 17, 2026.

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