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Mitochondrial Research

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

In plain language

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.

Technical detail

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.

Interactive diagram

How cells make energy

Tap each stage to see what happens.

Fuel: Glucose and fatty acids are broken down in the cell.

Background: Mitochondrial Research

Mitochondria turn nutrients and oxygen into ATP, the cell's energy currency. Their function declines with age and in several diseases.

Compounds in this area target the inner mitochondrial membrane, NAD+ supply or signalling peptides encoded by mitochondrial DNA. Human outcome data remains sparse.

Research Areas & Routes Studied

Areas studied
  • Mitochondrial function
  • Ageing biology
  • Exercise capacity
  • Cognition and fatigue
Routes used in research
  • 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.

Evidence pyramid

Higher tiers carry more weight. Filled tiers have evidence for NAD+; tap to read it.

Human clinical trials
  • 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.
  • Registered trials examine NAD+ precursors in ageing, heart failure, Parkinson's disease and post-viral fatigue.
Source breakdown

3 cited sources.

  • Randomised controlled trial1
  • Narrative review1
  • Regulatory document1

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.

How to Read This Research

Questions to ask
  • Did the study show a functional change (exercise capacity, fatigue) or only a lab marker?
  • Was the population healthy, elderly or living with a specific mitochondrial disease?
Reading tips
  • Raising blood NAD+ levels does not confirm tissue-level benefit.
  • Disease-specific trial results do not automatically apply to healthy people.
ATP
Adenosine triphosphate, the cell's energy currency.
Cardiolipin
A lipid unique to the inner mitochondrial membrane.
NAD+
A coenzyme central to energy metabolism and DNA repair.

Compare With Other Compounds

Compare side by side
NAD+MOTS-c
Evidence gradeC — Early Human ResearchD — Preclinical Research
Regulatory statusNot FDA ApprovedResearch Use Only
Human dataLimitedLimited
Clinical trialsRegistered trials existNone identified
Research routesIntravenous infusion (clinics), Subcutaneous injection (research), Oral precursors (NR, NMN) in most published trialsIntraperitoneal (animal research), Subcutaneous (animal research)
Cited sources32
Also in Mitochondrial Research

Frequently Asked Questions

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

    View Study
  • Narrative review

    NAD+ metabolism in ageing and disease

    View Study
  • Regulatory document

    Registered NAD+ and NAD+ precursor trials

    View Clinical Trial
This page is an educational research summary. It is not medical advice, does not recommend human use, and does not provide individualised dosing. Many compounds discussed here are research use only and are not approved medicines.