Section 01
What it's used for
Lifespan extension in animals
Restoring NAD+ directly, a molecule cells need to produce energy, has been shown to extend lifespan in animal models. This remains an animal-only finding; it has not been shown to extend lifespan in people yet.
▸Clinical wording
- Direct NAD+ restoration has been shown to extend lifespan in animal models
- IV NAD+ infusions rapidly increase blood and tissue NAD+ levels with 100% bioavailability
- Supports DNA repair, mitochondrial function, and sirtuin activation — key longevity pathways
Cellular energy production
NAD+ is studied for boosting how efficiently mitochondria, the energy factories inside cells, produce ATP, the molecule cells burn as fuel, which supports the body's overall energy production throughout each day.
▸Clinical wording
- Enhances mitochondrial energy production and ATP synthesis
- Improves insulin sensitivity and supports healthy glucose metabolism
- Reduces chronic low-grade inflammation linked to metabolic syndrome
Link to Alzheimer's and Parkinson's
Falling NAD+ levels in the body are closely linked to how Alzheimer's disease and Parkinson's disease progress, an association researchers are studying, though it does not by itself prove that raising NAD+ changes outcomes.
▸Clinical wording
- NAD+ depletion is closely linked to Alzheimer’s and Parkinson’s disease progression
- IV NAD+ therapy is being studied for neuroprotective effects in neurodegenerative conditions
- Supports neuronal energy supply and DNA damage repair in brain cells
Blood vessel health
NAD+ is studied for promoting healthy function of the endothelium, the thin inner lining of blood vessels, and for supporting the natural elasticity that lets blood vessels flex and relax properly with each heartbeat.
▸Clinical wording
- Promotes healthy endothelial function and blood vessel elasticity
- Helps reduce arterial stiffness associated with aging
- Supports cardiac energy metabolism and heart muscle contractility
Support during addiction recovery
Intravenous NAD+ therapy, delivered directly into the bloodstream through a vein, is being researched as a possible support during recovery from substance abuse, though this use is still being actively investigated.
▸Clinical wording
- IV NAD+ therapy is being researched for substance abuse recovery support
- May help reduce withdrawal symptoms and cravings
- Supports neurochemical balance restoration
Section 02
Mechanism of Action
The cell's reusable energy shuttle
- A helper molecule (NAD+) accepts electrons in energy-releasing reactions and is reused rather than used up.
- The nucleus, the cell fluid and the mitochondria each keep a separate supply, built by different enzymes.
- Mitochondria also import ready-made NAD+ through a carrier that three research groups identified independently.
- Several enzymes cut this molecule apart instead of recycling it, so the cell must keep rebuilding it.
▸Clinical wording
Redox cycling and compartmentalized NAD+ pools
NAD+ is the electron-accepting cofactor of catabolic reactions, cycling between the oxidized and reduced forms without being consumed. Separate nuclear, cytosolic and mitochondrial pools are maintained by distinct adenylyltransferases: NMNAT1 in the nucleus, NMNAT2 on the cytosolic face of the Golgi, NMNAT3 in mitochondria. Mitochondria do not rely on local synthesis alone; three groups independently identified SLC25A51 as the carrier that imports intact NAD+ across the inner membrane. Because sirtuins, PARPs and CD38 cleave NAD+ rather than recycle it, these pools depend on continuous resynthesis.
Three ways the body builds it
- One route starts from the amino acid tryptophan and runs mainly in the liver.
- A second route converts nicotinic acid taken in from food through an intermediate step.
- A third route recycles the nicotinamide released by enzymes that consume NAD+, the slowest and controlling step.
- All three meet at the final step that adds an adenyl group to give NAD+.
▸Clinical wording
Three biosynthetic routes converging on NMN
NAD+ is built by three routes. The de novo or kynurenine pathway starts from tryptophan and runs mainly in the liver, with indoleamine 2,3-dioxygenase as its rate-limiting step and quinolinate phosphoribosyltransferase feeding the product forward. The Preiss-Handler pathway converts dietary nicotinic acid through nicotinic acid mononucleotide. The salvage pathway recycles the nicotinamide released by NAD+-consuming enzymes, with NAMPT catalysing the rate-limiting conversion to NMN. All three converge on the NMNAT-catalysed step that adds the adenylyl group to give NAD+.
How the supplements get inside cells
- Gene experiments showed one enzyme (NRK1) is necessary and rate-limiting for using supplemental nicotinamide riboside and NMN.
- The same enzyme is not needed for nicotinamide or nicotinic acid.
- Tracer studies showed NMN outside the cell loses a phosphate and enters as nicotinamide riboside.
- In humans single oral doses of 100, 300 and 1000 mg raised blood NAD+ markers dose-dependently.
▸Clinical wording
NRK1-dependent entry of nicotinamide riboside and NMN
Genetic gain- and loss-of-function work showed nicotinamide riboside kinase 1 is necessary and rate-limiting for the use of exogenous NR and NMN, while being dispensable for nicotinamide or nicotinic acid. Stable-isotope tracing showed extracellular NMN is dephosphorylated to NR before uptake, which explains the overlapping effects of the two compounds; CD73 performs that dephosphorylation, and a direct NMN transporter, SLC12A8, has been described in intestinal epithelium. In humans single oral doses of 100, 300 and 1000 mg NR raised the blood NAD+ metabolome dose-dependently, with NAAD emerging as a sensitive marker of repletion.
Switching on cellular maintenance enzymes
- In cells and mouse tissues nicotinamide riboside raised NAD+ and activated two maintenance enzymes (SIRT1 and SIRT3).
- Those mice showed more oxidative metabolism and protection against abnormalities caused by a high-fat diet.
- One enzyme strips chemical tags from a protein that switches on fat-burning genes in fasting muscle.
- The same enzyme also lowers inflammation-related gene transcription (NF-kappaB) by modifying a partner protein.
▸Clinical wording
Sirtuin activation and mitochondrial oxidative metabolism
In mammalian cells and mouse tissues NR raised NAD+ and activated SIRT1 and SIRT3, with enhanced oxidative metabolism and protection against high-fat-diet-induced metabolic abnormalities. SIRT1 deacetylates PGC-1alpha, and in fasting skeletal muscle that deacetylation is required to switch on mitochondrial fatty-acid-oxidation genes. SIRT1 also deacetylates FOXO3, tipping the oxidative-stress response toward cell-cycle arrest and stress resistance rather than apoptosis, and deacetylates RelA/p65 at Lys310, which lowers NF-kappaB-dependent transcription.
Enzymes that burn through the supply
- A DNA-repair enzyme (PARP1) does roughly 90% of that repair work and competes for the same NAD+ pool.
- A surface enzyme (CD38) breaks NAD+ down, and a nerve enzyme (SARM1) does the same while driving axon degeneration.
- Across mouse tissues the surface enzyme rises two- to threefold with age and moves opposite to NAD+ levels.
- Mice lacking it kept NAD+ constant with age, with higher liver enzyme activity and mitochondrial oxygen consumption.
▸Clinical wording
NAD+-consuming enzymes and the age-related decline
PARP1 accounts for roughly 90% of PARP activity after DNA damage and competes with sirtuins for the same NAD+ pool; the ectoenzyme CD38 hydrolyses NAD+ to nicotinamide and ADP-ribose; the neuronal TIR-domain enzyme SARM1 is an NAD+ hydrolase whose activity drives axon degeneration. CD38 expression and activity rise two- to threefold across mouse tissues with age and correlate inversely with NAD+ (r = -0.95); in CD38-knockout mice tissue NAD+ stayed constant with age, liver SIRT3 activity was 3.5-fold higher and mitochondrial oxygen consumption about 2.5-fold higher. CD38 also degrades NMN directly.
What human trials have actually shown
- Six weeks of oral nicotinamide riboside in healthy middle-aged and older adults was tolerated and raised NAD+ metabolism.
- The authors framed blood pressure and arterial stiffness as effects worth testing further, not as demonstrated benefits.
- In a 10-week placebo-controlled trial, NMN raised insulin-stimulated glucose disposal in postmenopausal women with prediabetes.
- Muscle samples in that trial also showed changed signalling and changed expression of remodelling genes.
▸Clinical wording
Human observations on precursor supplementation
Six weeks of oral NR in healthy middle-aged and older adults was well tolerated and raised NAD+ metabolism in a randomized crossover trial, with the authors framing blood pressure and arterial stiffness as effects worth testing further rather than as demonstrated benefits. In a 10-week randomized, placebo-controlled trial in postmenopausal women with prediabetes who were overweight or obese, NMN increased insulin-stimulated glucose disposal measured by hyperinsulinaemic-euglycaemic clamp, along with skeletal-muscle AKT and mTOR phosphorylation and expression of PDGF receptor beta and other remodelling genes.
Section 03
Biological Pathways
- NRK1-dependent precursor uptakeNicotinamide riboside kinase 1 is necessary and rate-limiting for cells to use exogenous NR and NMN, dephosphorylated to NR by CD73 before uptake; oral NR raises the blood NAD+ metabolome dose-dependently.
- Salvage synthesis converging on NAD+Three routes, the kynurenine, Preiss-Handler and salvage pathways, all feed an NMNAT-catalysed step producing NAD+; NAMPT catalyses the salvage pathway's rate-limiting conversion of nicotinamide to NMN.
- Sirtuin-driven metabolic signalingRestored NAD+ activates SIRT1 and SIRT3; SIRT1 deacetylates PGC-1-alpha to switch on fatty-acid-oxidation genes in fasting muscle and deacetylates FOXO3, tipping stress response toward resistance over apoptosis.
- CD38 consumption and age-related declineThe ectoenzyme CD38 hydrolyses NAD+ and NMN directly; its activity rises two- to threefold with age and correlates inversely with tissue NAD+, while CD38-knockout mice keep NAD+ constant with age.
- Human metabolic effects of repletionIn randomized trials, oral NR was well tolerated and raised NAD+ metabolism in older adults, while NMN improved insulin-stimulated glucose disposal and muscle AKT/mTOR signaling in overweight prediabetic women.
Section 04
Dosage Information
| Route / system | Context | Range studied | Limitation |
|---|---|---|---|
| Oral — nicotinic acid (niacin) | FDA lipid label — the only approved NAD precursor | Slow-release niacin, 500 mg nightly up to 1000–2000 mg daily — 11–29 mg/kg. In muscle disease, 1 g daily for a year raised NAD+ 8-fold | Approved for lipids, not for NAD+. A 2 g trial in 25 673 patients found no heart benefit and more diabetes, infection and bleeding; flushing is near universal. |
| Oral — nicotinamide | Phase 3 skin-cancer prevention trial | 500 mg twice daily for a year in 386 people with past skin cancer — about 11–14 mg/kg for a 70–90 kg adult. Non-melanoma cases fell 23% | The only precursor with a positive phase 3 result — a skin outcome in people already prone to skin cancer. The same dose did nothing in transplant patients. |
| Oral — nicotinamide riboside | Randomised trials, from healthy adults to patients | 100–1000 mg daily raised NAD+ 22–142% in 8 weeks; 2 g daily for 12 weeks in insulin-resistant men; 3 g daily for 30 days in Parkinson's | The most-studied precursor and the clearest miss: 2 g a day for 12 weeks changed nothing — insulin sensitivity, energy burn, fat breakdown, body composition. |
| Oral — nicotinamide mononucleotide | Randomised trials, healthy and prediabetic adults | 250–900 mg daily for 30–90 days doubled to tripled blood NAD+; 250 mg raised muscle insulin sensitivity 25%; tested to 1250 mg, 4 weeks | Better marketed than NR, not better proven: the one clinical result rests on 25 participants, and the walking and wellbeing result is the maker's own trial. |
| Intravenous — NAD+ itself | Wellness-clinic drips; one blood-level pilot | Clinics drip 250–1000 mg over 2–4 hours. Published: 750 mg over 6 hours in 8 healthy men, one 500 mg drip, and 500 mg over ~97 minutes | No controlled trial has tested a course of drips against placebo. All six clients in that chart review had moderate to severe cramps, nausea or chest pressure. |
| Oral, under-tongue and injected products | The intact molecule sold directly, outside any trial | Labels list 250–1000 mg per oral or under-tongue dose, 50–200 mg per injection two to three times a week, and 10–30 mg per nasal spray | None of these figures comes from a trial: every human number above is a swallowed precursor or a vein drip, carried onto routes nobody has measured. |
Results
Syringe Fill Level (100u syringe)
Set positive values for: Recommended dose per kg.
Research Use Only. This information is for educational and research purposes only. Not intended for medical advice or self-medication.
Section 05
Protocols
- Protocol 01
Comprehensive Longevity Stack
Multi-peptide anti-aging protocol combining telomerase activation, mitochondrial support, and GH optimization.
- Focus
- Anti-Aging
- Level
- Advanced
- Duration
- 3–6 months
- Protocol 02
NAD+ Restoration Protocol
Protocol for restoring cellular NAD+ levels using one of three interchangeable approaches: direct NAD+ administration, NMN supplementation, or Nicotinamide Riboside (NR). Choose ONE approach based on your budget, preferred route, and goals. NAD+, NMN, and NR all raise NAD+ levels — they are alternatives, not a stack. NAD+ levels decline ~50% between ages 40-60, contributing to aging, cognitive decline, and metabolic dysfunction. Restoring NAD+ supports DNA repair, mitochondrial function, sirtuin activation, and cellular energy production.
- Focus
- Anti-Aging
- Level
- Beginner
- Duration
- Ongoing
Section 06
Stability & Storage
Storing the product
NMN and NR are relatively stable as dry powders and are kept at room temperature in cool, dry conditions; some products recommend refrigeration instead. NMN is generally more stable than NR.
After opening
Once opened, containers are resealed promptly and kept away from moisture and heat, since both compounds degrade with humidity exposure. NR is more sensitive than NMN, so refrigeration after opening is a common precaution for both.
Section 07
Side Effects & Precautions
NAD+ precursors are well tolerated at standard doses in clinical trials; effects appear at higher doses and differ by form, and a theoretical cancer-metabolism concern has not been observed in human studies.
Dose-related effects
At standard doses, NAD+ precursors are well tolerated in clinical trials. At higher doses, mild digestive discomfort can occur, including nausea and bloating.
Flushing depends on the form
Flushing (skin warmth and redness) occurs with high-dose niacin, but not with NMN or NR.
A theoretical cancer-metabolism concern
Cancer cells use NAD+ in their metabolism, raising a theoretical concern, though this has not been observed in human studies.
Section 08
Regulatory Status
Nicotinamide Riboside (NR)
Lawful dietary ingredient
FDA cleared it twice as a New Dietary Ingredient (NDI 882 in 2015, NDI 1062 in 2018) and once as GRAS (GRN 635, 2016); the EU authorised it as a novel food in 2020. Sold worldwide as Niagen / Tru Niagen.
Nicotinamide Mononucleotide (NMN)
Reinstated as a supplement in 2025
FDA excluded NMN from the dietary-supplement definition in 2022 over a prior drug investigation, then reversed that call on 29 September 2025 after a citizen petition and a lawsuit. It stays a disputed Novel Food in the EU and is banned outright in China.
Intravenous NAD+
Not a dietary supplement
FDA treats injectable NAD+ as a drug; no NAD+ injectable is FDA-approved, so IV clinics use product compounded under 503A/503B pharmacy rules with a prescription, and no published randomised trial confirms a clinical benefit from the infusions.
WADA
Not on the Prohibited List
Neither NR, NMN nor NAD+ itself appears anywhere in WADA's 2026 Prohibited List, under S0, S2 or any other category.
Regulatory status differs by exact compound and by route of administration, and it keeps changing — NMN's swing from excluded to reinstated inside three years is the clearest example. Check the current rules where you are before buying or using any of these products.
Section 09
Research Studies
- [1]NAD+ metabolism and its roles in cellular processes during ageingCovarrubias AJ, Perrone R, Grozio A, Verdin E. · Nature Reviews Molecular Cell Biology · 2021
- [2]Maestro of the SereNADe: SLC25A51 Orchestrates Mitochondrial NAD+Ouyang Y, Bott AJ, Rutter J. · Trends in Biochemical Sciences · 2021
- [3]NRK1 controls nicotinamide mononucleotide and nicotinamide riboside metabolism in mammalian cellsRatajczak J, Joffraud M, Trammell SA, et al. · Nature Communications · 2016
- [4]Nicotinamide riboside is uniquely and orally bioavailable in mice and humansTrammell SA, Schmidt MS, Weidemann BJ, et al. · Nature Communications · 2016
- [5]The NAD+ precursor nicotinamide riboside enhances oxidative metabolism and protects against high-fat diet-induced obesityCanto C, Houtkooper RH, Pirinen E, et al. · Cell Metabolism · 2012
- [6]Metabolic control of muscle mitochondrial function and fatty acid oxidation through SIRT1/PGC-1alphaGerhart-Hines Z, Rodgers JT, Bare O, et al. · The EMBO Journal · 2007
- [7]Stress-dependent regulation of FOXO transcription factors by the SIRT1 deacetylaseBrunet A, Sweeney LB, Sturgill JF, et al. · Science · 2004
- [8]Modulation of NF-kappaB-dependent transcription and cell survival by the SIRT1 deacetylaseYeung F, Hoberg JE, Ramsey CS, et al. · The EMBO Journal · 2004
- [9]CD38 Dictates Age-Related NAD Decline and Mitochondrial Dysfunction through an SIRT3-Dependent MechanismCamacho-Pereira J, Tarrago MG, Chini CCS, et al. · Cell Metabolism · 2016
- [10]Distinct developmental and degenerative functions of SARM1 require NAD+ hydrolase activityBrace EJ, Essuman K, Mao X, et al. · PLoS Genetics · 2022
- [11]Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adultsMartens CR, Denman BA, Mazzo MR, et al. · Nature Communications · 2018
- [12]Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic womenYoshino M, Yoshino J, Kayser BD, et al. · Science · 2021
Section 10
Frequently Asked Questions
Every precursor route reliably raises the blood NAD+ metabolome, but that is a laboratory marker, not a symptom. Individual clinical results are mixed: nicotinamide reduced non-melanoma skin cancer 23% in a phase 3 trial, while nicotinamide riboside at 2 g daily for 12 weeks changed nothing metabolic in insulin-resistant men. No controlled trial has tested a course of IV NAD+ drips against placebo at all.
This has not been measured. The published human data describe infusion length, not onset of effect - 750 mg over 6 hours in 8 healthy men, a single 500 mg drip, and 500 mg over about 97 minutes - with no trial tracking when, or whether, a subjective or clinical effect appears.
Oral precursors are generally well tolerated in trials, with mild nausea or bloating at higher doses. The IV route looks different in the only published look at real-world use: a retrospective chart review found all six clients experienced moderate to severe cramps, nausea or chest pressure during their drip, and no controlled trial has assessed IV NAD+ safety over repeated sessions.
No interaction study has been published for NAD+ or its precursors with any of these medications. The absence of data is not evidence of safety; it means the combination has simply not been tested.
Nicotinamide riboside carries FDA GRAS status as a dietary-supplement ingredient; NMN's regulatory status varies by country and has been debated in the US regarding supplement versus investigational-drug classification. IV NAD+ itself is not FDA-approved as a drug and is offered by wellness clinics outside that framework; none of these forms is on WADA's prohibited list.
NMN and NR are kept as dry powders at room temperature in cool, dry conditions, though some product labels call for refrigeration instead; NMN is generally the more stable of the two. Once opened, containers are resealed promptly, since both compounds degrade with moisture exposure - NR more so than NMN.
This has not been studied. None of the clinical trials behind NAD+ precursors enrolled pregnant women or people with significant kidney or liver disease, so no safety data exist for those groups specifically.