NAD+ (IV/SubQ)

Overview

Nicotinamide adenine dinucleotide (NAD+) is a coenzyme present in every cell, central to cellular energy metabolism — acting as an electron carrier in glycolysis, the citric acid cycle, and oxidative phosphorylation — and to non-redox signaling functions, including as a substrate for sirtuins (NAD+-dependent deacetylases implicated in aging biology) and PARP enzymes involved in DNA repair. NAD+ levels decline with age, and this decline has been proposed as a contributor to age-related metabolic and mitochondrial dysfunction. That basic biology is well established.

What is not well established is the clinical benefit of directly infusing NAD+ intravenously or subcutaneously in humans. The great majority of human clinical trial evidence cited in support of "NAD+ therapy" was actually conducted using oral NAD+ precursor supplements — nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) — not intravenous or subcutaneous NAD+ itself. This distinction matters and is addressed directly in the evidence section below: IV/SubQ NAD+ marketing routinely borrows credibility from a different, oral-precursor evidence base.

Also known as: NAD+ (oxidized form); related precursor compounds nicotinamide riboside (NR, sold under proprietary names such as Niagen) and nicotinamide mononucleotide (NMN). No FDA-approved NAD+ drug product exists; NR and NMN are marketed as dietary supplements, with NMN's supplement status subject to ongoing regulatory uncertainty. IV/SubQ NAD+ used in clinics is generally a compounded preparation, prepared under state pharmacy law and physician order.

How it works

NAD+ exists in oxidized (NAD+) and reduced (NADH) forms and shuttles electrons through core metabolic pathways, making it essential to ATP production. Beyond its redox role, NAD+ is the obligate substrate for two enzyme families implicated in aging and cellular-stress biology: sirtuins (SIRT1-7), which regulate mitochondrial biogenesis, inflammation, and stress resistance and are proposed to decline in activity as NAD+ falls with age; and PARPs, which consume NAD+ during DNA-damage repair. CD38, an NAD+-consuming enzyme whose activity increases with age and chronic inflammation, contributes further to age-related NAD+ decline.

NAD+ itself is a large, charged molecule with poor oral bioavailability — the scientific rationale offered for IV/SubQ administration, which bypasses gut absorption. But whether intravenously infused NAD+ is taken up intact by peripheral tissues in a way that meaningfully raises intracellular NAD+ levels in tissues relevant to aging or energy claims — versus being metabolized or cleared before reaching target tissue — has not been rigorously established in humans. By contrast, the oral precursors NR and NMN are smaller molecules absorbed and enzymatically converted to NAD+ intracellularly via well-characterized salvage pathways. It is this oral-precursor pathway, not direct IV NAD+ infusion, that carries the stronger human trial support.

There is a striking lack of published human pharmacokinetic data specifically for IV NAD+ infusion. A 2022 review that searched for clinical evidence supporting IV NAD+ supplementation found very limited published data.² No large (more than 100 participants) randomized controlled trial of IV NAD+ has been published in a peer-reviewed journal, and no long-term (more than 6 months) safety study of repeated IV NAD+ infusions exists. IV infusions are typically administered over one to four-plus hours in clinic settings; subcutaneous injections use smaller volumes; oral NR/NMN are taken as capsules.

What the research shows

Animal / preclinical evidence

Basic-science work on sirtuins, PARPs, and CD38 establishes the mechanistic rationale for NAD+'s role in aging and cellular-stress biology, and underlies the broader hypothesis that restoring declining NAD+ levels could have metabolic benefit. This preclinical and mechanistic foundation is genuinely well grounded — the gap is specifically in translating it to a validated clinical benefit from IV or subcutaneous NAD+ administration in humans.

Human evidence

The best human data available for the NAD+ pathway come from oral precursor trials, not IV. Martens et al. (2018) ran a randomized, double-blind, placebo-controlled crossover trial in 60 adults aged 55–79: six weeks of oral nicotinamide riboside (500 mg twice daily) was well tolerated and increased blood NAD+ metabolites.¹ This is an oral precursor trial, not an IV NAD+ trial, and its primary endpoints were NAD+ metabolite levels and tolerability, not hard clinical outcomes. Multiple additional oral NR/NMN human trials from 2016–2023 have similarly shown that oral precursors raise blood NAD+ levels and are generally well tolerated at studied doses (typically 250–1000 mg/day), with some smaller trials suggesting modest improvements in specific surrogate markers such as blood pressure or insulin sensitivity in select populations — but effect sizes are generally modest and results are inconsistent across trials for many claimed benefits.

For IV NAD+ specifically: a 2022 review of the clinical evidence base found the literature "remarkably bare," consisting primarily of case reports, small uncontrolled pilot studies, and clinic-published case series rather than peer-reviewed randomized controlled trials.² No large randomized controlled trial of IV NAD+ has been published in a peer-reviewed journal as of this writing. No head-to-head trial comparing IV NAD+ to oral NMN/NR for any clinical outcome has been published, meaning claims that IV administration is "more effective" than oral precursors are not evidence-based. No long-term (more than 6 months) safety study of repeated IV NAD+ infusions has been published. IV NAD+ clinics frequently market the therapy for substance-use-disorder withdrawal support and chronic fatigue syndrome; these claims rest primarily on case series, anecdotal clinical reports, and preclinical or animal work on NAD+ depletion in addiction neurobiology — not on placebo-controlled human trials specific to IV NAD+.

Honest assessment: The scientific case for NAD+ biology and aging is well grounded in basic science. The human clinical trial evidence that exists is for oral NAD+ precursors, and even that evidence, while real and peer-reviewed, mostly shows favorable tolerability and biomarker changes rather than robust improvements in hard clinical endpoints. Evidence for IV or subcutaneous NAD+ specifically — the form Aurafil dispenses — is essentially absent from the peer-reviewed literature. Claims made by IV therapy clinics extrapolate from the oral precursor data and animal models, a gap patients considering this therapy should understand clearly.

Typical use and dosing

The ranges below reflect published trials (for oral precursors) and clinic-practice conventions (for IV/SubQ NAD+, which lack dose-ranging trial support) — presented for education, not as a prescribing recommendation.

IV and subcutaneous dosing patterns reflect clinic-practice convention, not published dose-ranging trials — this gap is a meaningful part of the honest picture for anyone considering the therapy.

Safety, side effects, and who should avoid it

Oral NR and NMN are the better-characterized forms: generally well tolerated in trials, with occasional mild gastrointestinal upset, flushing, or headache. The Martens 2018 trial specifically concluded NR was "well-tolerated" over six weeks in older adults.¹ IV NAD+ is less well characterized — reported adverse effects during infusion (nausea, cramping, chest tightness, flushing) come from clinical practice experience and small case series rather than controlled trial safety data, and many clinics slow infusion speed in response.

There's a theoretical, unestablished concern regarding NAD+'s role in supporting cellular proliferation broadly — cancer biology research on NAD+ metabolism has raised hypothetical questions about whether NAD+-boosting therapies could theoretically support tumor metabolism, though this has not been demonstrated as a clinical risk in the precursor trials conducted to date. Injection-site reactions are reported with subcutaneous administration. No standardized clinical monitoring protocol exists specifically for NAD+ IV therapy, reflecting its status outside formal drug development and clinical trial infrastructure.

Regulatory status

No FDA-approved NAD+ drug product exists for IV or subcutaneous administration; IV/SubQ NAD+ is generally provided as a compounded preparation under state pharmacy and medical practice law. NAD+ for injection does not appear on the FDA's 503A/503B Category 1/2/3 interim bulk substance lists, meaning it has not been through the same nomination-and-safety-review process applied to peptides like BPC-157 and CJC-1295 — its regulatory status is best described as an unreviewed compounding gray area rather than an explicitly sanctioned or explicitly prohibited one.³

Oral NR is broadly marketed as a dietary supplement under DSHEA. Oral NMN's dietary-supplement status has been contested in FDA correspondence in recent years, and remains a moving target worth checking against current FDA guidance. No specialty medical society has issued a clinical practice guideline or position statement on IV or subcutaneous NAD+ therapy — no endocrine, geriatric, internal medicine, or addiction medicine society has endorsed IV NAD+ for any indication. The oral precursor literature has been reviewed in geroscience and nutrition science circles with cautious optimism about NAD+ biology as an aging-research target, but no oral precursor supplement has been endorsed by a clinical guideline body for a specific disease indication either — the field remains investigational.

NAD+, NR, and NMN are not listed on the WADA Prohibited List — they are not banned substances in competitive sport, unlike GHRH analogs, GHRPs, and IGF-1 analogs discussed elsewhere on this site.⁴ No FDA safety communication specific to IV NAD+ clinics has been issued as part of the broader 2023–2026 peptide-regulation wave, which focused on injectable peptides rather than NAD+ coenzyme therapy.

Frequently asked questions