The coenzyme behind cellular energy, DNA repair, and healthy aging — and how to restore levels that decline with age.
Nicotinamide adenine dinucleotide (NAD+) is a coenzyme found in every living cell. It is essential for hundreds of metabolic processes including ATP energy production, DNA repair, and the regulation of aging-related pathways.
NAD+ declines with age, and that decline is linked to mitochondrial dysfunction, cognitive decline and metabolic disease. The best primary human measurement is Massudi 2012 (PMID 22848760): pelvic skin tissue from 49 people aged newborn to 77, showing a strong inverse correlation between NAD+ and age (males r = −0.706, p = 0.001; females r = −0.537, p = 0.01), alongside rising PARP activity.
This guide previously said levels “decline by roughly 50% by age 40.” That specific figure circulates widely but we could not source it to a primary human study. What the data supports is a correlation measured in one tissue in 49 people, with sex differences — a real finding, and a smaller one than the headline number implies.
There are two primary ways to raise NAD+:
Not FDA approved for anti-aging. Available through compounding pharmacies and research suppliers. Not prohibited by WADA.
NAD+ is a critical electron carrier in the mitochondrial electron transport chain. Without adequate NAD+, ATP synthesis slows and cellular energy drops.
Sirtuins are NAD+-dependent enzymes that regulate DNA repair, genomic stability, inflammation, fat metabolism, insulin sensitivity, and circadian rhythm. They cannot function without NAD+.
PARP enzymes consume NAD+ to repair DNA strand breaks. As DNA damage accumulates with age, PARP activity increases, further depleting NAD+ in a vicious cycle.
NAD+ levels naturally oscillate throughout the day. Disrupted NAD+ levels contribute to circadian dysfunction, poor sleep, and metabolic dysregulation.
CD38, an enzyme that increases with age and inflammation, is a major consumer of NAD+. CD38 inhibition is a recognized NAD+-preservation strategy (PMIDs 33353981, 24786309); compounds like quercetin and apigenin are commonly cited but their efficacy as CD38 inhibitors at practical oral doses in humans has not been confirmed.
NAD+ research spans decades, and a 2026 PRISMA systematic review (Gallagher, PMID 41655607) is the best single summary of where it stands: 113 eligible studies, 33 of them human interventions. Oral NR and NMN consistently raise NAD-related metabolites and are well tolerated over weeks to months — biochemical target engagement is not in doubt. But effects on functional, metabolic and vascular outcomes were “heterogeneous and often null or endpoint-specific,” and the reviewers conclude clinical effectiveness for anti-aging remains inconclusive.
The finding that matters most for this page: that review identified no outcomes trials of intravenous or intramuscular NAD+ itself for anti-aging or wellness. One non-randomised IV NMN study contributed short-term safety and biomarker data, and an IV NAD+ pharmacokinetic pilot had no clinical outcomes. The injectable protocols below are extrapolated from oral-precursor biochemistry, not from trials of injected NAD+.
| Benefit | Evidence |
|---|---|
| Cellular energy | Directly fuels ATP production in the electron transport chain; users often report improved energy within the first week |
| Metabolic health | Contested. Yoshino 2021 (Science, PMID 33888596) reported improved muscle insulin sensitivity on NMN in prediabetic women — and drew four published comments. Brenner (PMID 34326206) noted the NMN group began with hepatic lipid of 6.3% versus 14.8% in placebo (p = 0.003) and argued that since liver-fat clearance is an NMN target, “this was not an effectively randomized trial” |
| Cognitive function | Sirtuin-mediated neuroprotection; improved mental clarity and focus commonly reported |
| DNA repair | PARP-dependent repair of DNA strand breaks; critical for genomic stability and cancer prevention |
| Anti-aging | Addresses a root cause of aging — NAD+ depletion drives mitochondrial dysfunction, inflammation, and cellular senescence |
| Cardiovascular support | Supports vascular function and endothelial health; may help maintain healthy blood pressure |
| Addiction recovery | IV NAD+ used in clinical detox settings to support neurotransmitter repair during substance dependence recovery |
Build your protocol, log every dose, monitor your body's response, and get reminders so you never miss a dose.
Start Tracking FreeNot medical advice. These figures describe what is reported in the literature and what practitioners and communities do — not a recommendation, and for most compounds here no human dose-finding study exists. Talk to a qualified healthcare provider.
SubQ NAD+ often causes a short-lived flushing / burning sensation. Start small, inject slowly, and scale only if tolerated.
On the two “support” compounds usually listed here. Resveratrol is routinely called a sirtuin activator; two papers found it is not a direct one — Beher 2009 (PMID 19843076) and Pacholec 2010 (PMID 20061378), the latter also clearing SRT1720, SRT2183 and SRT1460. The original activation signal was an artefact of the fluorophore-tagged substrate used in the assay. Resveratrol may still act on sirtuin pathways indirectly, but “SIRT1 activator” is not an accurate description.
Quercetin is listed for CD38 inhibition. As the mechanism section above already notes, CD38 inhibition is a real NAD-preservation strategy, but quercetin’s efficacy as a CD38 inhibitor at practical oral doses in humans has not been confirmed. Both are commonly stacked; neither is established.
Not medical advice. These figures describe what is reported in the literature and what practitioners and communities do — not a recommendation, and for most compounds here no human dose-finding study exists. Talk to a qualified healthcare provider.
Injectable NAD+ comes as a lyophilized powder. Reconstitution is straightforward but note the shorter shelf life compared to most peptides.
500 mg vial + 3 mL BAC water = 166.7 mg/mL
| Dose | Volume | Syringe Units |
|---|---|---|
| 25 mg (starter) | 0.15 mL | 15 units |
| 50 mg | 0.30 mL | 30 units |
| 100 mg | 0.60 mL | 60 units |
Vial duration: ~10 days at 50 mg/day, ~5 days at 100 mg/day
Pre-filled with a typical NAD+ setup. Edit any field — the draw updates live.
Insulin syringe — 100 units = 1 mL
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How fast does it work?
Most people notice energy and mental clarity improvements within the first week. Deeper benefits (DNA repair, mitochondrial function) accumulate over weeks to months.
Injectable vs. oral?
Injectable provides direct bioavailability and faster results. Oral precursors (NMN/NR) are more convenient for long-term maintenance. Many use injectable loading followed by oral maintenance.
What should I stack with NAD+?
TMG (methylation support), B vitamins, and SS-31 (dual mitochondrial support). Resveratrol and quercetin/apigenin are commonly added — but resveratrol is not a direct SIRT1 activator (PMIDs 19843076, 20061378) and quercetin’s CD38 inhibition is unconfirmed at human oral doses. Note: CD38 inhibition is a recognized NAD+-preservation strategy (PMIDs 33353981, 24786309), but the specific efficacy of quercetin or apigenin as CD38 inhibitors at practical oral doses in humans has not been confirmed in the referenced sources — treat the “CD38 inhibitor” framing as mechanistically plausible rather than human-validated.
Do I need to cycle?
Injectable: loading phase (7–10 days), then ongoing maintenance 1–3× weekly. Oral precursors can be taken continuously. No strict cycling required.
NAD+ is sold for research use only. If you are sourcing it for research, we recommend Lyvn — every batch third-party tested with the full laboratory panel published on the product page.
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For research use only. Not for human consumption. 21+.
Build your protocol, log every dose, monitor your body's response, and get reminders so you never miss a dose.
Start Tracking FreeNo. NAD+ is not FDA approved as a drug for any indication. Injectable NAD+ is compounded by pharmacies by compounding pharmacies; oral and sublingual forms are sold as dietary supplements under DSHEA without FDA approval. NMN (nicotinamide mononucleotide) lost its dietary-supplement status in late 2022 after FDA determined a pharmaceutical company had filed an IND; NR (nicotinamide riboside) and NAD+ itself remain available as supplements.
Subcutaneous: community-practice 50–250 mg per injection, daily or every other day, often in 4–8 week cycles. IV: clinic protocols typically run 250–1000 mg per infusion, weekly to monthly. Oral / sublingual: 100–500 mg/day. None of these dose ranges come from FDA-approved labeling — they reflect clinic and community convention.
For a 500 mg lyophilized vial, a typical reconstitution is 500 mg + 3 mL of bacteriostatic water, yielding 166.7 mg/mL. A 100 mg subcutaneous dose draws to 0.60 mL (60 units on a 100-unit insulin syringe). NAD+ is light-sensitive — store the reconstituted vial in the refrigerator, protected from light, and use within 14 days. Do NOT freeze (degrades the molecule).
Subcutaneous: injection-site irritation, redness, swelling — slower injection helps. IV: the most common side effects during infusion are chest pressure, flushing, headache, GI discomfort, and a feeling of "running through your veins." These are infusion-rate dependent — slowing the drip rate reduces them. Reactions resolve within minutes of stopping or slowing the infusion.
All three feed into the same NAD+ salvage pathway. NAD+ is the molecule itself; NMN and NR are precursors that the body converts to NAD+ intracellularly. Oral NAD+ has poor bioavailability (largely degraded by digestion). NR has the best human RCT base (~10 small Phase 1/2 trials showing increased blood NAD+ levels). NMN has more limited human data, complicated by its 2022 loss of dietary-supplement status. Injectable NAD+ bypasses GI degradation entirely but carries the side-effect profile above and is more expensive.
NAD+ levels decline with age, and animal studies of NAD+ precursors show effects on mitochondrial function, sirtuin activity, and various aging biomarkers. Human RCTs (mostly with NR) have demonstrated that supplementation raises blood NAD+ levels — but have not demonstrated changes in clinically meaningful aging endpoints (lifespan, healthspan, disease incidence). The "anti-aging" framing in marketing exceeds the current human evidence base.
Disclaimer: This guide is for educational and informational purposes only and is not intended as medical advice, diagnosis, or treatment. The compounds discussed are not FDA approved for human use. Always consult a qualified healthcare provider before starting any new supplement or peptide protocol. StackTrax does not sell peptides or supplements directly — purchase links go to third-party vendors. StackTrax is not responsible for the products, quality, or business practices of any third-party vendor.
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StackTrax guides cover peptides and compounds that are not FDA-approved for the uses discussed. The dosing, reconstitution, and safety information is compiled from published research and community protocols for educational purposes only.
Before using any compound mentioned here, consult a qualified healthcare provider. StackTrax does not sell, prescribe, or recommend these substances for personal use.