D tier · weak
Injected NAD+ itself has only small pilot human studies with a poor tolerability profile relative to alternatives, and the substantial randomised human literature people cite for it actually belongs to oral precursors, not to IV NAD+.
nad+ (injectable/iv)
NAD+ is a dinucleotide coenzyme, not a peptide, and injectable or intravenous NAD+ is a distinct proposition from the oral precursors nicotinamide riboside and nicotinamide mononucleotide that carry most of the published randomised evidence. Human data on IV NAD+ amount to small pilot studies showing that it does raise circulating NAD+ metabolites but is slow and unpleasant to infuse compared with an infused precursor.
// we supply this one
available as a research reagent
≥ 99% HPLC · lyophilised powder · batch certificate published. Grade D above is our own and is not adjusted because we stock it.
the explanation
NAD+ is a molecule every cell uses to run its energy chemistry, and it drops with age. Clinics sell it as an IV drip, but the actual human research behind the anti-ageing claims mostly comes from pills containing NAD+ building blocks, not from the drip itself.
regulatory status
Not an FDA-approved drug in any injectable form
There is no FDA-approved NAD+ injection or infusion product for any indication. Injectable NAD+ administered in clinics is compounded material; NAD is not currently listed on FDA's Category 2 roster of bulk drug substances that may present significant safety risks, but absence from that list is not approval and does not constitute an efficacy finding. Oral NAD+ precursors are marketed as dietary supplements, which is a separate regulatory category with no efficacy review.
how it works · proposed mechanism
NAD+ is a redox cofactor and a consumed substrate, and the distinction between those two roles drives most of the confusion around supplementing it.
Redox cofactor role
NAD+/NADH cycling carries electrons through glycolysis, the TCA cycle and oxidative phosphorylation. This pool is recycled rather than consumed, so it is not obviously limited by supply.
Consumed-substrate role
Sirtuins, PARPs and CD38 cleave NAD+ and release nicotinamide, genuinely consuming the molecule. This consumption, and rising CD38 activity with age, is the usual argument for declining tissue NAD+.
Why the route matters
NAD+ is too large and charged to enter cells intact and is degraded extracellularly before salvage. Infusing NAD+ therefore delivers precursors indirectly, which is why an infused precursor can outperform it on the same molar dose.
what’s reported
evidence shape
5 sourcesThe composition of the cited literature by study type. This describes the shape of the evidence, not its quality — and it does not by itself set the grade.
⚠ the catch
This entry is not a peptide at all - it is a nucleotide coenzyme - and it is routinely bundled into peptide catalogues where it does not belong. Nearly every randomised trial cited in support of NAD+ therapy tested an oral precursor, so the strongest-sounding evidence for IV NAD+ is evidence for something else entirely.
key published findings
- Human trial (open pharmacokinetic pilot, Grant et al., Frontiers in Aging Neuroscience 2019, n=11 with 8 treated): during a 6-hour 750 mg IV NAD+ infusion, no change in plasma NAD+ or metabolites was detectable until after 2 hours, then NAD+ rose about 398%, nicotinamide about 409%, ADP-ribose about 393% and methylnicotinamide about 350% by 6 hours, with increased urinary methylnicotinamide excretion.
- Human trial (randomised, double-blind pilot, medRxiv 2024, study 1 n=37 and study 2 n=16): IV nicotinamide riboside produced a 20.7% blood NAD+ rise at 3 hours, statistically superior to both IV NAD+ and oral NR (p<0.01), on a matched 500 mg dose.
- Human trial (same 2024 pilot): IV NAD+ required a mean 99 minutes of infusion time versus about 25 minutes for IV NR, and was associated with nausea, headache and gastrointestinal disturbance during infusion, plus elevated white blood cell and neutrophil counts not seen with NR.
- Human observational (retrospective tolerability comparison, Frontiers in Aging 2026): a real-world review comparing IV NAD+ with IV nicotinamide riboside again found NAD+ infusions less well tolerated.
- Mechanistic: the delayed onset and metabolite pattern in the 2019 pilot are consistent with extracellular degradation via CD38 glycohydrolase and NAD+ pyrophosphatase followed by intracellular salvage, rather than direct cellular uptake of intact NAD+.
limitations of the evidence
- Human IV NAD+ studies are pilot-scale (roughly a dozen to a few dozen participants), short, and measure blood metabolites rather than any clinical outcome.
- No randomised trial has shown that IV NAD+ improves a clinically meaningful endpoint - cognition, fatigue, function or longevity - in any population.
- The much larger randomised literature on nicotinamide riboside and nicotinamide mononucleotide applies to oral precursors and cannot be transferred to intravenous NAD+.
documented safety signals
- Infusion-associated nausea, headache, chest discomfort and gastrointestinal upset are common enough that infusion rate has to be slowed, which is why documented infusion times run to roughly 99 minutes for 500 mg.
- A 2024 randomised pilot reported elevated white blood cell and neutrophil counts after IV NAD+ that were not seen with IV nicotinamide riboside, raising an inflammatory-response question.
- Compounded injectable NAD+ has been subject to FDA recall activity over sterility and endotoxin-related quality concerns; product quality is a live issue independent of the molecule itself.
- No long-term safety data exist for repeated high-dose intravenous NAD+ in humans.
identity
| full name | Nicotinamide adenine dinucleotide, injectable and intravenous forms |
| category | Longevity |
| modality | small molecule |
| formula | C21H27N7O14P2 |
| molar mass | 663.43 g/mol |
| cas | 53-84-9 |
laboratory handling
| storage | Reference-grade NAD+ free acid is a crystalline solid specified for storage at -20C, protected from moisture; it is hygroscopic and hydrolytically unstable in neutral to alkaline aqueous solution, so solutions are prepared fresh. |
| solubility | Freely water-soluble; reference material dissolves in PBS at pH 7.2 at approximately 10 mg/mL, and much higher concentrations are achievable in water. |
| co-studied with | The comparative human evidence available so far favours infused nicotinamide riboside over infused NAD+ on both NAD+ elevation at 3 hours and tolerability, and the oral precursor literature (NR, NMN) is far larger than anything supporting the intravenous route. This is an evidence comparison, not a recommendation. |
Handling information describes laboratory practice for a research reagent. It is not a preparation guide for use in humans.
the receipts
5 citedUS Food and Drug Administration · 2025 · official
Frontiers in Aging Neuroscience · 2019 · randomized
medRxiv preprint · 2024 · randomized
Frontiers in Aging · 2026 · observational
Cayman Chemical technical documentation · 2025 · preclinical
others in Longevity