NAD+
Also referenced as: Nicotinamide adenine dinucleotide, NAD+ 500 mg vial
A central metabolic coenzyme studied for mitochondrial function and ageing biology, usually supplied as a 500 mg lyophilised research vial.
- Evidence grade
- CEarly Human Research
Early Human Research
- Regulatory status
- Not FDA Approved
NAD+ is not an approved medicine. Injectable and infused NAD+ products are sold outside the drug approval pathway, and research-use-only material is not intended for human use.
- Human data
- Limited
Registered clinical trials exist
- Last reviewed
- September 14, 2026
Overview
Nicotinamide adenine dinucleotide is a coenzyme present in every cell, where it carries electrons in energy metabolism and acts as a substrate for sirtuins and PARP enzymes.
Tissue NAD+ levels decline with age in several models, which is the basis for most interest in raising them. Whether raising NAD+ changes meaningful health outcomes in people remains unresolved.
Commonly supplied for research as a 500 mg vial. It is a nucleotide coenzyme rather than a peptide, and is grouped here because it is studied and discussed alongside peptide research compounds.
Why It's Being Studied
- Age-related decline in cellular NAD+ availability.
- Mitochondrial energy metabolism and exercise capacity.
- Sirtuin-dependent pathways in DNA repair and metabolic regulation.
- Fatigue, cognition and recovery, where claims greatly exceed the published data.
Mechanism of Action
NAD+ is a helper molecule the cell uses to turn food into usable energy and to run repair enzymes. Interest centres on topping it up as levels fall with age.
NAD+ cycles between oxidised and reduced (NADH) forms in glycolysis, the TCA cycle and oxidative phosphorylation, and is consumed as a co-substrate by sirtuins, PARPs and CD38. Direct extracellular NAD+ is largely degraded to nicotinamide and mononucleotide species before cellular uptake, so intracellular effects of infused NAD+ are likely mediated by precursor salvage through NAMPT and NMNAT enzymes.
Research Areas & Routes Studied
- Mitochondrial function
- Ageing biology
- Exercise capacity
- Cognition and fatigue
- Intravenous infusion (clinics)
- Subcutaneous injection (research)
- Oral precursors (NR, NMN) in most published trials
Evidence Summary
Human studies exist mostly for NAD+ precursors such as nicotinamide riboside and nicotinamide mononucleotide. Direct injected or infused NAD+ has very little controlled human data, and clinical outcome evidence is preliminary.
Human clinical evidence
- Randomised trials of oral nicotinamide riboside reliably raise blood NAD+ metabolites but show small or absent effects on functional endpoints.
- Controlled data on injected or infused NAD+ itself are very sparse, with mostly open-label or uncontrolled reports.
Clinical trials
- Registered trials examine NAD+ precursors in ageing, heart failure, Parkinson's disease and post-viral fatigue.
Animal studies
- Rodent work links restored NAD+ to improved mitochondrial function, stem-cell activity and metabolic parameters.
Anecdotal / community information
- Infusion clinics report subjective energy and clarity benefits. These reports are uncontrolled and open to placebo effects.
Reported Adverse Events in Research
- Infused NAD+ commonly causes flushing, chest tightness, nausea and cramping when given quickly.
- Injection-site reactions and infection risk apply to any injected preparation.
- Long-term safety of sustained supraphysiological NAD+ signalling has not been established.
Limitations of Current Evidence
- Most human evidence concerns precursors, not NAD+ itself, so results cannot be transferred directly.
- Blood NAD+ metabolite levels are a biomarker, not a health outcome.
- Dose, route and duration vary widely across reports, preventing comparison.
Why It Is Used
- Longevity
Energy and Mitochondrial Function
Fatigue that sleep does not fix is the entry point. Mitochondrial compounds are the most biologically interesting and least resolved category on this site.
Read the case study - Longevity
Healthy Ageing and Longevity
The category with the largest gap between ambition and evidence, and the one where the quality of the underlying research matters most.
Read the case study
Research References
- Randomised controlled trial
Nicotinamide riboside supplementation and NAD+ metabolism in humans
- Narrative review
NAD+ metabolism in ageing and disease
- Regulatory document
Registered NAD+ and NAD+ precursor trials