NAD+ (nicotinamide adenine dinucleotide) is a coenzyme central to redox reactions and energy metabolism in every cell. Cellular NAD+ levels decline measurably with age, which has motivated longevity-research interest in NAD+ supplementation. NAD+ itself has poor oral bioavailability, so research protocols use subcutaneous or IV administration, or precursors like NMN and NR.
Research notes
How does NAD+ work?
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme involved in hundreds of metabolic reactions, particularly the redox reactions that drive ATP production and the sirtuin enzyme family that's been studied in aging research. Cellular NAD+ levels decline measurably with age, which has motivated interest in supplementation as a longevity-protocol target.
NAD+ itself is a large, polar molecule with poor membrane permeability. Most research-protocol NAD+ administration is subcutaneous or IV because oral bioavailability is low. Precursors like NMN and NR are common alternatives because they cross membranes more efficiently and convert to NAD+ intracellularly.
What doses are used in research?
The published research-protocol literature spans a wide range. Common reference doses:
- 100–250 mg subcutaneous as a maintenance protocol
- 500 mg IV as an intensive single-dose research administration
- NMN / NR oral analogs typically dosed in the 250–1000 mg range
Half-life is short — NAD+ is rapidly partitioned across compartments and converted to downstream metabolites. The clinical question of whether boosting circulating NAD+ produces meaningful increases in tissue NAD+ levels is still being characterized in human trials.
What does the research show about side effects?
Most-reported research-protocol observations are administration-route specific. Subcutaneous NAD+ commonly produces flushing and a transient burning sensation at the injection site — this is mechanistically expected and generally resolves within minutes. IV administration at high doses can produce nausea and chest tightness if infused too quickly; protocols specify slow infusion rates accordingly.
What does this guide cover?
Vendor audits for NAD+ focus on:
- Identity confirmation — NAD+ is sometimes shipped as the precursor (NMN or NR) labeled as NAD+. Mass-spec identity confirmation is essential.
- Purity — NAD+ degrades during storage and shipping if not properly handled. Lower-purity batches often reflect storage problems rather than synthesis problems.
- Bacteriostatic water reconstitution — NAD+ is unstable in solution. Some research protocols specify sodium chloride 0.9% rather than bacteriostatic water; vendor packaging instructions vary.
What it's researched for
- cellular energy
- mitochondrial function
- aging research
Where to source it
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Frequently asked about NAD+
What is NAD+?
NAD+ is nicotinamide adenine dinucleotide, a coenzyme involved in hundreds of metabolic reactions — particularly the redox reactions that drive ATP production and the sirtuin enzyme family that has been extensively studied in aging research.
Why is NAD+ studied for longevity?
Cellular NAD+ levels decline measurably with age, and this decline is correlated with reduced sirtuin and PARP activity in published research. The hypothesis driving longevity-protocol interest is that restoring NAD+ levels may slow age-related metabolic dysfunction. Causal evidence in humans is still developing.
Why isn't NAD+ taken orally?
NAD+ is a large, polar molecule with poor membrane permeability and is rapidly broken down in the gut. Oral bioavailability is low. This is why most research-protocol NAD+ administration is subcutaneous or IV, and why NAD+ precursors like NMN and NR are popular alternatives — they cross membranes more efficiently and convert to NAD+ intracellularly.
What doses are used in NAD+ research?
Published research literature cites 100–500 mg subcutaneous or IV, with protocols ranging from single-dose tolerability studies to weekly maintenance schedules. Doses are highly variable across studies and protocols; this is not a settled dose range.
Is research-grade NAD+ the same as IV NAD+ at clinics?
The molecule is the same. The difference is that clinic-administered NAD+ is typically pharmaceutical-grade with a chain of custody under medical supervision, whereas research-grade NAD+ from peptide vendors is for laboratory research only and is not formulated, tested, or distributed for human use.