Longevity

NAD+: The Complete Guide

The coenzyme behind cellular energy, DNA repair, and healthy aging — and how to restore levels that decline with age.

14 min read|Updated April 16, 2026

What is NAD+?

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+ levels decline by roughly 50% by age 40. This decline is linked to mitochondrial dysfunction, cognitive decline, metabolic disease, and many hallmarks of aging. Restoring NAD+ levels is one of the most researched strategies in longevity science.

There are two primary ways to raise NAD+:

Injectable NAD+ SubQ or IM injection; bypasses digestion for direct bioavailability

Oral precursors (NMN / NR) Supplements that the body converts into NAD+; widely available over the counter

Not FDA approved for anti-aging. Available through compounding pharmacies and research suppliers. Not prohibited by WADA.

How It Works

Mitochondrial Energy Production

NAD+ is a critical electron carrier in the mitochondrial electron transport chain. Without adequate NAD+, ATP synthesis slows and cellular energy drops.

Sirtuin Activation (SIRT1–SIRT7)

Sirtuins are NAD+-dependent enzymes that regulate DNA repair, genomic stability, inflammation, fat metabolism, insulin sensitivity, and circadian rhythm. They cannot function without NAD+.

DNA Repair via PARP Enzymes

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.

Circadian Rhythm Regulation

NAD+ levels naturally oscillate throughout the day. Disrupted NAD+ levels contribute to circadian dysfunction, poor sleep, and metabolic dysregulation.

CD38 & Age-Related Decline

CD38, an enzyme that increases with age and inflammation, is a major consumer of NAD+. CD38 inhibitors like quercetin and apigenin may help preserve NAD+ levels.

Research & Benefits

NAD+ research spans decades. While injectable NAD+ human trials are limited, oral precursors (NMN, NR) have been studied in multiple clinical trials with promising results.

Benefit	Evidence
Cellular energy	Directly fuels ATP production in the electron transport chain; users often report improved energy within the first week
Metabolic health	NMN improved insulin sensitivity in prediabetic women (Yoshino et al.); supports glucose metabolism via sirtuin activation
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

Key Studies

Yoshino et al. (2021) — NMN 250 mg/day × 10 weeks improved insulin sensitivity in prediabetic postmenopausal women.
Multiple NMN/NR trials — Oral precursors at 250–2000 mg/day consistently raise blood NAD+ levels with good safety profiles.
Physical function trials — NMN supplementation improved walking distance and physical capacity in older adults.
Safety data — Doses up to 1000–2000 mg/day of oral precursors well tolerated across multiple clinical trials.

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Dosing Protocol

Injectable NAD+ — Starter Dose

Dose25 mg

PurposeAssess tolerance (flushing, warmth, nausea)

RouteSubQ — inject very slowly

SubQ NAD+ often causes a short-lived flushing / burning sensation. Start small, inject slowly, and scale only if tolerated.

Injectable NAD+ — Loading Phase

Dose50 – 100 mg

FrequencyDaily or every other day

Duration~10 days

RouteSubQ or IM

Injectable NAD+ — Maintenance

Dose50 mg

Frequency1 – 2× per week

RouteSubQ or IM

Oral Precursors (NMN / NR)

Starting 250 mg/day

Standard 500 mg/day

Higher Up to 1000 mg/day (diminishing returns above)

Timing & Tips

Best timeMorning (aligns with circadian NAD+ peak)

AvoidLate evening dosing (may disrupt sleep)

Support nutrientsTMG, Resveratrol, Quercetin, B vitamins

How to Reconstitute

Injectable NAD+ comes as a lyophilized powder. Reconstitution is straightforward but note the shorter shelf life compared to most peptides.

Step by Step

Draw the appropriate amount of bacteriostatic water (see chart below)
Insert needle into the vial at an angle
Let water trickle down the inside wall — do not inject directly onto the powder
Gently swirl until fully dissolved — do not shake
Solution should be clear and colorless; discard if cloudy

Draw Volume Reference

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

Storage — Important

Powder: Refrigerate 36 – 46°F; protect from light
Reconstituted: Refrigerate; use within 14 days (shorter than most peptides); do not freeze; discard if cloudy

Calculate Your Exact Dose

Use our free peptide calculator to figure out your reconstitution volume, draw amount, and syringe units.

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Dosing cheat sheet, reconstitution reference, and cycle planning — delivered to your inbox.

Side Effects & Safety

Common (usually mild, dose-dependent)

Flushing or warmth (especially with higher doses or IV)
Nausea
Headache
Fatigue (typically first few days)
Injection site tenderness

Less Common

Stomach discomfort (more common with oral precursors)
Insomnia (if dosed too late in the day)
Dizziness

Precautions

Active cancer — stronger than a general caution: NAD+ is a central metabolic cofactor for sirtuins, PARPs, and basic cellular bioenergetics (PMIDs 33353981, 7002341); enhancing NAD+ availability may theoretically support tumor cell metabolism and proliferation. Avoid or use only under oncologist supervision if you have active malignancy.
Use caution with: Liver or kidney disease, bleeding disorders, pregnancy or nursing
Start low: Begin with lower doses to assess tolerance, especially with injectable NAD+

FAQ

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), Resveratrol (sirtuin activator), Quercetin/Apigenin, B vitamins, and SS-31 (dual mitochondrial support). 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.

Where to Buy NAD+

Looking for NAD+? We recommend NextGen Peptides — third-party tested, fast shipping, and trusted by the StackTrax community.

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Track Your NAD+ Protocol

Track NAD+ with StackTrax

Build your protocol, log every dose, monitor your body's response, and get reminders so you never miss a dose.

Start Tracking Free

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. This page contains affiliate links — StackTrax may earn a commission on purchases at no extra cost to you.

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What is NAD+?

There are two primary ways to raise NAD+:

Injectable NAD+ SubQ or IM injection; bypasses digestion for direct bioavailability

Oral precursors (NMN / NR) Supplements that the body converts into NAD+; widely available over the counter

Not FDA approved for anti-aging. Available through compounding pharmacies and research suppliers. Not prohibited by WADA.

How It Works

Mitochondrial Energy Production

NAD+ is a critical electron carrier in the mitochondrial electron transport chain. Without adequate NAD+, ATP synthesis slows and cellular energy drops.

Sirtuin Activation (SIRT1–SIRT7)

Sirtuins are NAD+-dependent enzymes that regulate DNA repair, genomic stability, inflammation, fat metabolism, insulin sensitivity, and circadian rhythm. They cannot function without NAD+.

DNA Repair via PARP Enzymes

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.

Circadian Rhythm Regulation

NAD+ levels naturally oscillate throughout the day. Disrupted NAD+ levels contribute to circadian dysfunction, poor sleep, and metabolic dysregulation.

CD38 & Age-Related Decline

CD38, an enzyme that increases with age and inflammation, is a major consumer of NAD+. CD38 inhibitors like quercetin and apigenin may help preserve NAD+ levels.

Research & Benefits

NAD+ research spans decades. While injectable NAD+ human trials are limited, oral precursors (NMN, NR) have been studied in multiple clinical trials with promising results.

Benefit	Evidence
Cellular energy	Directly fuels ATP production in the electron transport chain; users often report improved energy within the first week
Metabolic health	NMN improved insulin sensitivity in prediabetic women (Yoshino et al.); supports glucose metabolism via sirtuin activation
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

Key Studies

Yoshino et al. (2021) — NMN 250 mg/day × 10 weeks improved insulin sensitivity in prediabetic postmenopausal women.
Multiple NMN/NR trials — Oral precursors at 250–2000 mg/day consistently raise blood NAD+ levels with good safety profiles.
Physical function trials — NMN supplementation improved walking distance and physical capacity in older adults.
Safety data — Doses up to 1000–2000 mg/day of oral precursors well tolerated across multiple clinical trials.

Dosing Protocol

Injectable NAD+ — Starter Dose

Dose25 mg

PurposeAssess tolerance (flushing, warmth, nausea)

RouteSubQ — inject very slowly

SubQ NAD+ often causes a short-lived flushing / burning sensation. Start small, inject slowly, and scale only if tolerated.

Injectable NAD+ — Loading Phase

Dose50 – 100 mg

FrequencyDaily or every other day

Duration~10 days

RouteSubQ or IM

Injectable NAD+ — Maintenance

Dose50 mg

Frequency1 – 2× per week

RouteSubQ or IM

Oral Precursors (NMN / NR)

Starting 250 mg/day

Standard 500 mg/day

Higher Up to 1000 mg/day (diminishing returns above)

Timing & Tips

Best timeMorning (aligns with circadian NAD+ peak)

AvoidLate evening dosing (may disrupt sleep)

Support nutrientsTMG, Resveratrol, Quercetin, B vitamins

How to Reconstitute

Injectable NAD+ comes as a lyophilized powder. Reconstitution is straightforward but note the shorter shelf life compared to most peptides.

Step by Step

Draw the appropriate amount of bacteriostatic water (see chart below)
Insert needle into the vial at an angle
Let water trickle down the inside wall — do not inject directly onto the powder
Gently swirl until fully dissolved — do not shake
Solution should be clear and colorless; discard if cloudy

Draw Volume Reference

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

Storage — Important

Powder: Refrigerate 36 – 46°F; protect from light
Reconstituted: Refrigerate; use within 14 days (shorter than most peptides); do not freeze; discard if cloudy

Side Effects & Safety

Common (usually mild, dose-dependent)

Flushing or warmth (especially with higher doses or IV)
Nausea
Headache
Fatigue (typically first few days)
Injection site tenderness

Less Common

Stomach discomfort (more common with oral precursors)
Insomnia (if dosed too late in the day)
Dizziness

Precautions

Active cancer — stronger than a general caution: NAD+ is a central metabolic cofactor for sirtuins, PARPs, and basic cellular bioenergetics (PMIDs 33353981, 7002341); enhancing NAD+ availability may theoretically support tumor cell metabolism and proliferation. Avoid or use only under oncologist supervision if you have active malignancy.
Use caution with: Liver or kidney disease, bleeding disorders, pregnancy or nursing
Start low: Begin with lower doses to assess tolerance, especially with injectable NAD+

FAQ

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+?

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.