NAD+ (Nicotinamide Adenine Dinucleotide)
The central redox coenzyme itself, sold and administered directly (usually by IV infusion or injection) as an anti-aging and recovery therapy. Tissue NAD+ decline is a genuine hallmark of aging, but evidence that infusing exogenous NAD+ meaningfully raises intracellular levels or improves outcomes in humans is weak; oral bioavailability is poor.
01 Overview
Nicotinamide adenine dinucleotide is the coenzyme at the heart of cellular energy metabolism and a substrate for sirtuins, PARPs, and CD38. Its tissue levels fall with age, which is the rationale for the entire NAD+-boosting field. Direct NAD+ is marketed as IV drips, subcutaneous injections, and (less effectively) oral or sublingual products.
Unlike its precursors, intact NAD+ is a large, charged molecule that is poorly absorbed orally and is largely degraded to nicotinamide and other metabolites before entering cells, so much of an IV dose likely acts as a precursor pool rather than being taken up whole. Clinical evidence is dominated by uncontrolled clinics and small studies; rigorous trials showing that exogenous NAD+ infusions extend healthspan or treat age-related disease are lacking. IV administration also carries infusion-related discomfort.
02 Mechanism
Serves as the electron carrier in redox reactions and as substrate for NAD+-consuming enzymes; supplied exogenously it is largely broken down to precursors that cells then re-synthesise into NAD+.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| SC injection | 50–100 mg/day | SubQ | Lower-volume home protocols; evidence base minimal. |
| IV drip (clinic) | 250–1000 mg | IV | Infused slowly over hours; rapid infusion causes flushing and chest tightness. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Restores a declining NAD+ poolAims to counter the well-documented age-related fall in tissue NAD+, though direct uptake of infused NAD+ is uncertain. | variable | Preclinical | |
| Subjective energy / recoveryUsers and clinics report improved energy and mental clarity; not established in controlled trials. | unquantified | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Cost and unproven benefitIV NAD+ is expensive and lacks controlled evidence of durable benefit over cheaper oral precursors. | Mild | Inherent | Unconfirmed | |
| Infusion reaction (flushing, chest tightness, nausea)Rapid IV NAD+ commonly causes flushing, chest or abdominal tightness, and nausea that resolve when the drip is slowed. | Moderate | Common with fast IV | Observational |