Peptide Health Lab

Longevity & cellular

NAD+

Also known as: Nicotinamide adenine dinucleotide, NAD

Regulatory status
Rx via compounding
Evidence grade
Anecdotal reports only

Last reviewed August 2, 2026 · 16 sources

What NAD+ is and how it works

NAD+ is not a peptide and it is not a drug candidate in the usual sense. It is nicotinamide adenine dinucleotide, a coenzyme present in every cell, and its first job is redox chemistry: it carries electrons through the reactions that turn food into usable energy.[12]

Its second job is what made it a longevity target. NAD+ is a required substrate, not merely a cofactor, for three families of enzymes that consume it as they work: sirtuins, poly(ADP-ribose) polymerases, and CD38. Through them it is wired into DNA repair, chromatin remodeling, cellular senescence, immune-cell function and metabolic signalling.[12] Because these enzymes destroy NAD+ in the act of using it, cellular NAD+ is a continuously spent and continuously resynthesized pool.

The observation the field is built on is that this pool declines with age across multiple organisms including humans, and that the decline has been linked to age-associated conditions.[12] From there the logic is simple and appealing: if the pool falls, refill it.

Refilling it is where the distinction that governs this entire page appears. NAD+ itself is a large, charged molecule that does not readily cross cell membranes, so most research has used precursors: nicotinamide riboside and nicotinamide mononucleotide, which the body converts into NAD+ internally.[2] Nearly every randomized controlled trial in this area tested a precursor taken by mouth. Almost none tested NAD+ itself, and the intravenous NAD+ that dominates the wellness conversation has been formally studied in humans exactly once, as a pharmacokinetic pilot.[8] When this page grades NAD+ at the compound level as anecdotal while grading several individual claims as randomized-trial evidence, it is marking the gap between what has been trialled and what is actually being administered.

What the research actually shows

Precursors reliably raise NAD+ in people. This is the field's solid ground. The first human pharmacokinetic trial of nicotinamide riboside found dose-dependent increases in the blood NAD+ metabolome after single doses of 100, 300 and 1,000 mg.[1] A randomized, double-blind, placebo-controlled crossover trial in healthy middle-aged and older adults confirmed chronic supplementation was well tolerated and stimulated NAD+ metabolism.[3] A dose-ranging trial in overweight adults reported whole-blood NAD+ rising 22%, 51% and 142% at the three dose levels within two weeks and holding for the rest of the study.[5] In aged men, 1 g daily for 21 days raised the skeletal muscle NAD+ metabolome directly, measured in biopsies.[6]

Functional outcomes are inconsistent, and often null. Twelve weeks of oral nicotinamide riboside in obese, insulin-resistant men produced no improvement in insulin sensitivity, glucose disposal, energy expenditure, lipolysis or body composition. That was a well-powered trial with a clean negative result.[4] A separate randomized trial found no change in muscle mitochondrial respiration, content or morphology.[10] The aged-muscle study found NAD+ rose while mitochondrial bioenergetics did not.[6] Against that, a randomized placebo-controlled trial of nicotinamide mononucleotide in postmenopausal women with prediabetes did report increased insulin-stimulated glucose disposal and muscle insulin signalling.[13] A meta-analysis of nineteen randomized trials found reductions in total cholesterol and triglycerides and no significant effect on other metabolic syndrome parameters, rating the evidence quality very low to low.[15]

Some signals are worth watching. Nicotinamide riboside depressed circulating inflammatory cytokines in aged men,[6] and a randomized phase I trial in thirty treatment-naive Parkinson's disease patients found 1,000 mg daily for 30 days raised cerebral NAD+ variably, altered cerebral metabolism in those whose brain NAD+ rose, and produced mild clinical improvement. The authors presented that as grounds for larger trials.[14] Other trials examined body composition and muscle acetylcarnitine[11] and endocrine pancreatic function.[7]

Injected NAD+ has been characterized once. A pilot study infused NAD+ at 3 µmol per minute over six hours and measured plasma and urine. Plasma NAD+ and its metabolites did not change until after the second hour, implying the molecule was rapidly and completely removed from circulation, and urinary methylnicotinamide and NAD+ rose by hour six.[8] That is a description of disposal, with no clinical endpoint attached.

Where the evidence is weak

The form with the most marketing has the least evidence. A 2026 PRISMA-guided systematic review screened human and rodent intervention studies from 2010 to 2025 and found 113 eligible studies. It stated that no eligible outcomes trials evaluated intravenous or intramuscular NAD+ itself for anti-aging or wellness indications.[16] The NAD+ infusion is not an under-studied intervention; on outcomes, it is an unstudied one.

Precursor evidence does not transfer to NAD+ itself. Nicotinamide riboside and nicotinamide mononucleotide are different molecules with different pharmacokinetics, and a trial of one is not evidence for the other.[2] Reading the randomized-trial literature as support for an infusion is the single most common error in this area.

Target engagement is not benefit. The same systematic review found that oral precursors consistently demonstrated biochemical target engagement but that effects on functional, metabolic and vascular outcomes were heterogeneous and often null or endpoint-specific.[16] Raising a laboratory value is the beginning of an argument, not the end of one.

Commercial interests are disclosed throughout. Several foundational pharmacokinetic and safety papers carry declarations of employment, equity or patent interests in companies that sell the compounds studied. The disclosures are published and appropriate; they are also a reason to weight independent replication over the earliest positive reports.[1][5]

Evidence quality is formally rated low. The metabolic-syndrome meta-analysis graded its evidence very low to low, citing risk of bias, imprecision and indirectness, with participant numbers outside lipid outcomes described as tiny.[15]

Long-term safety in humans is unknown. Trials ran weeks to months. Reviews state plainly that much remains to be learned about whether restoring NAD+ is safe in ageing humans, particularly given NAD+'s position inside DNA repair and senescence biology.[12]

Legal and regulatory status

NAD+ occupies two regulatory positions at once, and conflating them causes most of the confusion.

There is no FDA-approved injectable NAD+ drug product. Injectable NAD+ reaches patients as a compounded preparation made by a licensed pharmacy under a prescription. That is a clinical fact with consequences: a compounded preparation has no manufacturer-assigned indication, has not been through the approval process that establishes strength, purity and stability for a marketed drug, and is not evaluated by the FDA for effectiveness before it is dispensed.[16] Prescription-only also means the decision, the amount, the route and the monitoring are a clinician's to make against an individual clinical picture.

Oral precursors are a separate track. Nicotinamide riboside and nicotinamide mononucleotide have been studied as supplement ingredients rather than as approved drugs, and the trials on this page evaluated them in that capacity.[5] Being lawfully sold as a supplement ingredient is a regulatory status, not a finding of efficacy.

PHL does not sell anything and takes no position on how any preparation reaches anyone. What the regulatory picture means for a reader is narrower and more useful: the injectable form has no approved label and no outcomes trial, and the oral forms have trials whose functional results are mixed.[16]

Questions to bring to a provider

Because injectable NAD+ is prescription-only, this conversation is not optional. It is the mechanism by which the compound is accessed at all. Questions worth raising:

  • What is the actual problem being addressed, whether fatigue, cognitive complaints or a metabolic finding, and has it been worked up? Fatigue has a long differential that a coenzyme does not shorten.
  • Given that no outcomes trial of infused NAD+ exists, what specifically is the expected benefit and on what evidence does that expectation rest?[16]
  • Would an oral precursor, which does have randomized trials behind it, answer the same question at lower cost and lower risk?[3]
  • If glucose-lowering medication is already in use, how should the reported effects on insulin sensitivity be accounted for?[13]
  • Does a personal or family history of malignancy change the calculus, given NAD+'s position in DNA repair and senescence biology?[12]
  • Which laboratory work, symptom scales or functional testing would make it possible to tell whether anything actually changed, rather than relying on how a session feels afterwards?
  • For a compounded preparation, what does the dispensing pharmacy's own label say about strength, storage and beyond-use date?

A clinician who says the infusion evidence does not exist yet is describing the published record accurately.

Evidence by claim

Grades describe how strong the evidence is; the line under each grade describes what kind of studies it is. How we grade evidence.

Raising NAD+ and its metabolites in humans with oral precursors
Human RCT evidence human observational · human RCT

This is the best-established claim on the page and it is a biochemical one. Single oral doses of nicotinamide riboside produced dose-dependent increases in the blood NAD+ metabolome in the first human pharmacokinetic trial; chronic supplementation elevated NAD+ in healthy middle-aged and older adults in a randomized crossover trial; a dose-ranging trial reported whole-blood NAD+ increases of 22%, 51% and 142% at 100, 300 and 1,000 mg within two weeks; and 1 g daily for 21 days raised the NAD+ metabolome in aged human skeletal muscle. Target engagement is real.

[1] [3] [5] [6]

Insulin sensitivity and metabolic outcomes
Human RCT evidence human RCT · review

The results conflict. A 10-week randomized placebo-controlled trial of oral nicotinamide mononucleotide in postmenopausal women with prediabetes reported increased insulin-stimulated glucose disposal and muscle insulin signalling. A 12-week randomized placebo-controlled trial of nicotinamide riboside in obese, insulin-resistant men found no improvement in insulin sensitivity, energy expenditure, lipolysis or body composition. A meta-analysis of 19 randomized trials found reductions in total cholesterol and triglycerides but no significant effect on other metabolic syndrome parameters, with evidence quality rated very low to low.

[13] [4] [15]

Skeletal muscle mitochondrial function and body composition
Human RCT evidence human RCT

Largely null. Nicotinamide riboside raised the muscle NAD+ metabolome in aged men but downregulated energy-metabolism and mitochondrial gene pathways without altering mitochondrial bioenergetics; a separate randomized trial found no change in mitochondrial respiration, content or morphology in muscle from obese, insulin-resistant men; a third reported altered body composition and muscle acetylcarnitine concentrations in healthy obese participants. Biochemistry moves; function largely does not.

[6] [10] [11]

Endocrine pancreatic function and incretin hormones
Human RCT evidence human RCT

A randomized controlled trial in nondiabetic men with obesity examined nicotinamide riboside's effects on endocrine pancreatic function and incretin hormones. It belongs on this page as an example of the pattern: well-conducted trials asking specific mechanistic questions and returning modest or null answers.

[7]

Inflammatory markers and neurological disease
Human RCT evidence human RCT

Nicotinamide riboside depressed circulating inflammatory cytokines in aged men, and a randomized phase I trial in thirty newly diagnosed, treatment-naive Parkinson's disease patients found that 1,000 mg daily for 30 days was well tolerated, raised cerebral NAD+ variably, and, in those whose brain NAD+ rose, altered cerebral metabolism with mild clinical improvement. The authors describe it as nominating the compound for further investigation in larger trials, which is the correct reading.

[6] [14]

Healthspan and disease models in rodents
Animal studies only review

The rodent literature is where the enthusiasm comes from. Reviews describe NAD+ augmentation improving metabolic, mitochondrial, inflammatory and functional outcomes across many mouse models, and a 2026 systematic review counted 80 rodent studies against 33 human intervention studies. Effects varied across models and endpoints.

[2] [16]

Intravenous or injected NAD+ for energy, wellness or anti-aging
Anecdotal reports only human observational · review

This is the form most people mean when they say NAD+, and it is the form with the least evidence. The only published human study of an NAD+ infusion is a pilot pharmacokinetic investigation with no clinical endpoints, and a 2026 PRISMA-guided systematic review states directly that no eligible outcomes trials evaluated intravenous or intramuscular NAD+ itself for anti-aging or wellness indications. There is no efficacy literature here to grade.

[8] [16]

Slowing or reversing human aging
Anecdotal reports only review

NAD+ declines with age in multiple organisms and that decline is linked to age-associated disease, which is the biological premise for the whole field. Reviews are explicit that much remains to be learned about whether restoring NAD+ is beneficial or safe in ageing humans, and the most recent systematic review concludes that clinical effectiveness for anti-aging or wellness outcomes remains inconclusive.

[12] [16]

Typical protocol range in the research

  • The oral nicotinamide riboside amounts used in published randomized controlled trials, described as trial arms rather than as guidance

    100, 300 and 1,000 mg daily for 8 weeks in a dose-ranging safety trial; 1,000 mg daily for 21 days in aged men; 1,000 mg twice daily for 12 weeks in obese, insulin-resistant men; 1,000 mg daily for 30 days in newly diagnosed Parkinson's disease [5] [6] [4] [14]

  • Single-dose oral nicotinamide mononucleotide amounts used in a non-randomized safety study of ten healthy men

    Single oral administrations of 100, 250 and 500 mg [9]

  • Intravenous NAD+ itself, in the only published human pharmacokinetic description of an infusion

    3 µmol per minute infused over 6 hours; plasma NAD+ and its metabolites did not change until after the second hour [8]

  • Subcutaneous, intramuscular or intravenous NAD+ for energy, wellness or anti-aging indications

    No published trial establishes an amount for any of these indications; a 2026 PRISMA-guided systematic review found no eligible outcomes trials evaluating intravenous or intramuscular NAD+ itself for anti-aging or wellness [16]

The first two entries describe nicotinamide riboside and nicotinamide mononucleotide, oral precursor molecules rather than NAD+ itself. Both are trial arms, not schedules anyone is being pointed toward. The third is a pharmacokinetic experiment, not a treatment. Compounded NAD+ is prescription-only, which means the amount, route and interval are set by a prescribing clinician against an individual clinical picture, and no published literature supplies that number.

Ranges are what published research reports, not a recommendation. PHL does not prescribe, and nothing here is personalized to you.

Side effects & safety signals

  • Oral precursors were generally well tolerated in trials

    No serious adverse events attributed to treatment across the randomized trials reviewed, over weeks to months · A dose-ranging trial of oral nicotinamide riboside in overweight adults reported that the compound was well tolerated with normal safety laboratory results, and a 2026 systematic review of 33 human intervention studies characterized oral nicotinamide riboside and nicotinamide mononucleotide as generally well tolerated over weeks to months. That is a statement about oral precursors in trial populations, not about injected NAD+ and not about indefinite use.

    [5] [16]

  • Parenteral NAD+ has no safety trial behind it

    Not established · The only published human study of infused NAD+ is a pilot pharmacokinetic investigation, and a 2026 systematic review identified no eligible outcomes trials of intravenous or intramuscular NAD+ for anti-aging or wellness indications. Absence of reported harm from a literature that has barely looked is not evidence of safety. Infusion-route risks such as line access, infusion reactions and volume are clinical matters that belong with the supervising clinician.

    [8] [16]

  • Infusion and injection tolerability, the risk readers actually meet and the one nobody has measured

    Not characterized in any published trial · Infusion-site discomfort, flushing, nausea, chest tightness and lightheadedness during an NAD+ drip are the effects most commonly described by people who have had one, and the published literature has nothing to say about any of them. The single human study of an NAD+ infusion measured plasma and urine metabolites over six hours and reports no adverse-event data at all. It contains no tolerability table, no infusion-reaction count, and no symptom log. A 2026 PRISMA-guided systematic review found no eligible outcomes trials of intravenous or intramuscular NAD+ and classified that pharmacokinetic pilot as contextual evidence only. It is worth being precise about what the oral literature does and does not lend here: the dose-ranging trial of oral nicotinamide riboside specifically reported no flushing, which is a finding about an oral precursor taken by mouth and says nothing about what an intravenous dinucleotide feels like going in. Rate, volume, line access and any reaction during an infusion are matters for the clinician supervising it, and the honest description of the evidence is that this is uncharacterized rather than reassuring.

    [8] [16] [5]

  • Rapid clearance and methyl-group consumption

    Observed in the single published infusion study · During a 6-hour infusion, NAD+ was removed from plasma rapidly and completely for at least the first two hours, and urinary excretion of methylnicotinamide rose by hour six. Nicotinamide disposal consumes methyl groups, so sustained high-dose exposure has a theoretical interaction with methyl-donor status. It has not been studied over time in people and is a reason to raise the compound with a clinician.

    [8] [12]

  • Metabolic activity relevant to glucose-lowering therapy

    Reported in one randomized trial, absent in others · A randomized placebo-controlled trial of oral nicotinamide mononucleotide in postmenopausal women with prediabetes reported increased insulin-stimulated glucose disposal, while a randomized trial of oral nicotinamide riboside in obese men found no change in insulin sensitivity. Where glucose-lowering medication is already in use, an agent with any reported effect on this axis is a provider-discussion flag rather than an afterthought.

    [13] [4]

  • Intersection with cancer and DNA-repair biology

    Not quantified in humans · NAD+ is a required cofactor for poly(ADP-ribose) polymerases, sirtuins and CD38, placing it directly inside DNA repair, senescence and immune signalling. Reviews are explicit that much remains unknown about whether raising NAD+ is safe in ageing humans. A personal or family history of malignancy is a reason to raise this with a clinician before considering anything.

    [12] [2]

  • Compounded preparations carry no manufacturer label

    Not quantified · A compounded injectable is prepared by a licensed pharmacy under a prescription; it is not an FDA-approved drug product, has no manufacturer-assigned indication, and has not been through the approval pathway that establishes strength, purity and stability for a marketed drug. That is a structural fact about the category, and it sits on top of whatever the molecule itself does.

    [16]

Published lists are never exhaustive, so report anything unexpected to a licensed provider.

Storage, handling & reconstitution

Lyophilized storage
Where NAD+ is supplied as a lyophilized powder it is conventionally kept refrigerated at 2–8 °C and protected from light, with freezing used for long-term holding. The published NAD+ literature is concerned with metabolism and clinical outcomes rather than vial shelf life, so no study cited on this page establishes a storage window; the conventions here come from general practice for a light-sensitive dinucleotide.
Reconstituted storage
Once in solution, NAD+ preparations are conventionally refrigerated at 2–8 °C, protected from light, and treated as short-dated. A compounded preparation dispensed under a prescription carries a beyond-use date assigned by the compounding pharmacy on its own label. That label, not a reference page, governs how long the preparation is considered usable.
Reconstitution diluent
Compounded NAD+ for injection is frequently dispensed as a prepared sterile solution rather than as a powder needing reconstitution; where a lyophilized form is dispensed, the diluent is specified on the pharmacy's own label. Sterile or bacteriostatic water are the conventional diluents for lyophilized parenteral preparations generally, but for a compounded product the dispensing label is the governing instruction, not a general convention.
Reconstitution & handling
Conventional handling: sanitize the stopper before piercing it, add any specified diluent slowly down the inside wall of the vial rather than directly onto the powder, allow it to dissolve without shaking, and protect the solution from light. Anything cloudy, discolored, or carrying visible particulate is discarded. PHL does not publish volume or unit calculations, because those are dosing decisions, and for a prescription-only compounded preparation those decisions belong to the prescribing clinician.
Handling notes
There is no FDA-approved injectable NAD+ drug product, so there is no manufacturer label, no approved stability programme, and no lot-level release testing behind any general storage claim. Where a compounded preparation is dispensed, the pharmacy's labeling is the authoritative document and any question about it belongs with the prescribing clinician or that pharmacy.

The how-to guides cover the conventions behind these fields, and what the published stability data does and does not establish: Storage, Reconstitution, Handling.

Goal pages that include NAD+

Each one starts from the goal rather than the molecule, and grades what the evidence supports for that goal specifically.

  • Anti-Aging

    A research reference for the compounds mapped to longevity and healthy aging. It sets out what the randomized human trials of oral NAD+ precursors and DHEA actually measured, why the injected forms have no outcomes evidence at all, and where the rest is mice and cell culture.

  • Cognitive Function

    An honest map of a goal this library cannot serve. No compound reviewed on this site has human evidence of improving cognition, and the three that were tested against a cognitive endpoint each returned a null result.

Questions for your provider

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Citations

16 sources · every identifier checked against PubMed

Before you act on any of this

This page is educational only and is not medical advice. It does not diagnose, treat, or prescribe. Review it with a licensed provider before making any health decision. Peptide Health Lab does not sell peptides.

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