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NAD+

Also known as Nicotinamide adenine dinucleotide, NAD, beta-NAD+

Not a peptide but a coenzyme: central to energy metabolism, popular as an infusion on strikingly thin evidence.

early-clinical Immune & longevity supplement

At a glance

Category
Immune & longevity
Status
supplement
Route
intravenous (infusion), subcutaneous, intranasal, oral (as precursor)
Half-life
very short in plasma; NAD+ is cleared rapidly during infusion and mainly metabolites appear in the urine
Onset
not reliably established
Molecular weight
663.43 g/mol

NAD+ is not a peptide but a dinucleotide coenzyme, built from nicotinamide mononucleotide and adenosine monophosphate. It is nowhere registered as a medicine for ageing, fatigue or cognition. Oral precursors (nicotinamide riboside, nicotinamide mononucleotide) are sold as food supplements; their status differs per country and NMN has been excluded by the FDA as a dietary supplement in the US. Intravenous NAD+ infusions are offered by private clinics and fall outside any registration.

Doping status: Not listed by WADA; an infusion of more than 100 ml per 12 hours does fall under the ban on intravenous infusions (WADA M2.2)

Checked against the WADA 2026 Prohibited List. For a specific product and country, Global DRO is the lookup athletes are expected to use — the List names substances, not brand names.

Mechanism of action

NAD+ is the central redox coenzyme of the cell: it takes up electrons in glycolysis, beta-oxidation and the citric acid cycle and passes them to the electron transport chain. Without NAD+, ATP production comes to a halt.

In addition, NAD+ is a substrate — not a cofactor — for three enzyme families that consume the molecule: sirtuins (SIRT1-7, involved in gene regulation and mitochondrial biogenesis), PARPs (DNA repair) and CD38 (immune signalling). In DNA damage and chronic inflammation, PARPs and CD38 consume a great deal of NAD+, which feeds the theory that NAD+ declines with age.

The problem with infusions: NAD+ is a large, negatively charged molecule that does not enter cells directly. It must be broken down outside the cell into nicotinamide riboside or nicotinamide, which are then taken up and rebuilt into NAD+ inside the cell via the salvage pathway. This means that physiologically an NAD+ infusion functions as a roundabout way of administering nicotinamide.

The frequently heard claim that an infusion gives '100% bioavailability' confuses presence in the blood with uptake into the cell. What reaches the blood is indeed the full dose; what reaches the cell are the breakdown products.

What the research shows

The biochemistry of NAD+ is uncontested, the clinical claims around it are not. For intravenous NAD+ there is one small pharmacokinetic study and beyond that almost nothing: a 2026 PRISMA-guided systematic review of human and rodent intervention studies published between January 2010 and October 2025 identified 113 eligible studies and states that no eligible outcomes trial evaluated intravenous or intramuscular NAD+ itself for anti-ageing or wellness indications 5. Such evidence as exists concerns oral precursors, where it has indeed been shown that the NAD+ level in blood rises — but where clinical effects in healthy people are largely absent. NAD+ infusions are offered commercially on the basis of a biochemical rationale, not on the basis of clinical evidence.

Research in humans

Grant et al. (2019) gave eight healthy men 750 mg NAD+ intravenously over six hours (approximately 2 mg per minute) and tracked the NAD+ metabolome in plasma and urine 12. A rise in plasma NAD+ appeared only after about two hours and there was considerable excretion of NAD+ and metabolites in the urine 12 — an indication that a large part of the dose leaves the body unused. That study had no clinical endpoints. For oral precursors there are dozens of randomised studies with nicotinamide riboside and NMN: these reliably raise the NAD+ concentration in blood and are well tolerated, but show few consistent effects in healthy adults on muscle strength, exercise capacity, insulin sensitivity or cognition. That picture is what the 2026 systematic review reports: across 33 human intervention studies it found no eligible outcomes trial of intravenous or intramuscular NAD+ for anti-ageing or wellness indications, classified the intravenous NAD+ pharmacokinetic pilot as contextual evidence only because it lacked eligible clinical outcomes, and concluded that clinical effectiveness for these outcomes remains inconclusive 5. Retrospective research into the tolerability of NAD+ infusions in practice mainly describes side effects during the infusion 3.

Animal and lab research

In mice, raising NAD+ via precursors improves mitochondrial function, muscle regeneration and metabolic parameters, and effects on lifespan have been described in certain strains. These results have so far not translated into convincing clinical effects in humans.

Caveats. The human evidence for infusions consists of one pharmacokinetic study with eight participants and no clinical endpoint 12. There are no placebo-controlled studies of the frequently cited applications (fatigue, withdrawal, cognition, ageing) — the 2026 systematic review searched for exactly this and found no eligible outcomes trial 5. The commercial providers of infusions do not publish their outcomes. For precursors, a rise in NAD+ in the blood is a surrogate marker that does not automatically say anything about health or ageing.

What it is used for

  • Intravenous infusions in private clinics for 'energy', fatigue, cognition and ageing — without controlled evidence; a 2026 systematic review found no eligible outcomes trial of intravenous NAD+ for these indications 5
  • Support during withdrawal from alcohol and opioids (widely claimed, not confirmed in randomised studies)
  • Oral precursors (nicotinamide riboside, NMN) to raise the NAD+ level — for these, randomised research does exist
  • Nicotinic acid and nicotinamide as vitamin B3 in pellagra and in dyslipidaemia — registered, well-supported applications that are unrelated to the anti-ageing claims

Dosing

Dose
Infusions in practice 250-1500 mg per session; the only published pharmacokinetic study used 750 mg over six hours. Oral precursors: nicotinamide riboside 250-1000 mg per day, NMN 250-1000 mg per day.
Frequency
Infusions: in clinics often a series over several consecutive days, then monthly. Precursors: 1x daily.
Route
intravenous (slow infusion), subcutaneous, intranasal, oral
Duration
Not established; the published precursor studies ran 6-12 weeks
  • The infusion rate determines tolerability: rapid infusion causes shortness of breath, nausea, a pressing sensation in the chest and muscle cramp 3. Clinics therefore usually infuse over 2 to 8 hours.
  • Doses for infusions come from clinics and user protocols, not from validated clinical studies. There is no dose-response research, and no eligible outcomes trial of intravenous NAD+ was found by the 2026 systematic review 5.
  • A considerable part of an intravenous dose is excreted unchanged or as a metabolite in the urine.
  • Oral precursors are better studied, considerably cheaper and demonstrably raise the NAD+ level in blood — whether that delivers anything clinically in healthy people is another question.
  • These doses are given descriptively and do not constitute advice.
  • The clinic-infusion and DIY-injection practice is set out as a circulating protocol below. The only published intravenous study is a single eight-person pharmacokinetic pilot with no clinical endpoint 1; what circulates is repeated commercial infusions and self-injection sold for energy, ageing and withdrawal, for which a 2026 systematic review found no outcomes trial 5. It is recorded because readers encounter it, not because it is validated.

These figures describe what the literature and published protocols report. They are not advice and not a dosing instruction.

Protocols

Intravenous NAD+ pharmacokinetic study

published trial

Source: Frontiers in Aging Neuroscience, 2019 - pilot study of plasma and urine NAD+ during infusion

Single session, 6 hours750 mg NAD+ by slow intravenous infusion

A pharmacokinetic pilot in a handful of participants, not an efficacy trial: it tracked where the NAD+ went, and a considerable part appeared in urine. Clinic infusions of 250-1500 mg per session repeated over consecutive days are not this schedule and have no published basis; infusion rate, not dose, is what determines tolerability.

Clinic IV drips and DIY injection (circulating)

user protocol — not validated

Source: Private IV-clinic menus, wellness providers and user reports

This is not a validated schedule. It is a pattern that circulates among users and sellers, reproduced because it is what people actually follow — not because it has been tested. No trial established these doses, this interval or this duration, and nobody is checking what is in the vial. Treat every number below as an assertion, not a finding.

Clinic infusioncommonly 250-1500 mg intravenously per session over 2-8 hours, often a series on consecutive days and then monthly 'top-ups'
DIY routessubcutaneous self-injection and intranasal sprays of reconstituted powder, for 'energy', focus, anti-ageing or addiction recovery
How reports divergeno agreed dose, session length or course exists — the figures vary several-fold between clinics and sellers

The clinical block above is a single pharmacokinetic study in eight men with no clinical endpoint 1; the circulating use is repeated commercial infusions and DIY injection sold for energy, cognition, ageing and withdrawal. A 2026 systematic review that screened the field found no eligible outcomes trial of intravenous or intramuscular NAD+ for anti-ageing or wellness indications 5, so the clinic practice rests on a biochemical rationale rather than evidence, and providers do not publish their outcomes. Two facts about the figures matter. Tolerability is set by infusion rate, not dose: rapid infusion causes chest tightness, breathlessness, nausea and cramp, which is why clinics run it over hours 3. And a large part of an intravenous dose leaves the body unused in the urine 1, so the popular '100% bioavailability' claim confuses what reaches the blood with what reaches the cell. Subcutaneous and intranasal self-dosing have no published pharmacokinetic or safety basis at all. These figures are recorded because they circulate, not because any of them has been shown to do anything.

Schedules are reproduced as their source states them. Units, IU and milligrams explains why the figures are not interchangeable between products.

Reconstitution

Vial sizes
100 mg, 500 mg, 750 mg (powder for injection)
Solvent
sterile water for injection; for infusion further diluted in 0.9% NaCl or 5% glucose
Storage
Powder dry, cool and protected from light. NAD+ has limited stability in solution and is sensitive to hydrolysis; store reconstituted solution at 2-8 °C and use promptly.

Worked example

500 mg vial + 5 ml sterile water = 100 mg/ml. For an infusion this is diluted in 250-500 ml physiological saline and administered over several hours.

NAD+ is unstable in an alkaline environment. A discoloured solution indicates decomposition. Material sold as a research chemical has no pharmaceutical quality control and its purity is unknown.

This is given as an intravenous infusion, diluted further into a much larger volume. An insulin syringe is not the instrument involved, so no unit conversion is offered here.

Safety

Side effects

  • During infusion very common: a pressing or tight sensation in the chest, shortness of breath, nausea, abdominal cramp, muscle cramp, a sensation of warmth, restlessness — these complaints are strongly related to the infusion rate and disappear on slowing down 3
  • Headache and fatigue afterwards
  • A fall or indeed a rise in blood pressure during the infusion
  • Reaction at the infusion site, phlebitis; general risks of intravenous access such as infection
  • Flushing with nicotinic-acid-containing precursors (not with nicotinamide or NR)
  • Long-term safety of repeated infusions has not been studied

Do not use if

  • Pregnancy and breastfeeding: no data
  • Active malignancy: NAD+ supports DNA repair and cell proliferation; the effect on tumour growth has not been studied and is theoretically undesirable
  • Severe renal or hepatic impairment: clearance not studied
  • Infusions without medical supervision — the acute infusion reactions require the ability to slow down or stop the administration

Interactions

Not systematically studied. Nicotinamide in high doses can in fact inhibit the action of sirtuins and affects methylation status because it consumes methyl groups via nicotinamide N-methyltransferase. Interaction with chemotherapy that relies on DNA damage is theoretically relevant and has not been studied.

Common questions

What is NAD+ and what is it used for?
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme central to how cells produce energy. Its levels fall with age, which has made it popular as an anti-ageing infusion — but that popularity runs well ahead of the evidence.
Do NAD+ infusions work for anti-ageing or energy?
The human evidence is thin. NAD+ is genuinely important in metabolism, but that an IV drip meaningfully slows ageing or boosts energy in healthy people has not been shown in good trials. It is an expensive intervention on weak evidence.
What is the difference between NAD+, NMN and NR?
NAD+ is the coenzyme itself, usually given by infusion; NMN and nicotinamide riboside (NR) are oral precursors the body converts toward it. All three ride the same limited evidence.
Is NAD+ a peptide?
No — despite being sold in the same market, NAD+ is a coenzyme, not a peptide. It is included here because it is a mainstay of the longevity scene.

Sources