NAD+
Also known as Nicotinamide adenine dinucleotide, NAD, beta-NAD, Coenzyme 1
NAD+ is a coenzyme found in every living cell, not a peptide. It is central to energy metabolism and DNA repair, declines with age, and is injected or infused by people hoping to restore energy, cognition, and cellular resilience.
Overview
NAD+ is not a peptide. It is a small molecule made of two nucleotides joined by their phosphate groups, one containing adenine and the other nicotinamide. It shows up in peptide databases because it is sold as a lyophilized powder in vials, reconstituted with bacteriostatic water, and injected subcutaneously or intramuscularly by the same people who use peptides. It is a coenzyme, meaning it shuttles electrons in hundreds of metabolic reactions and serves as a substrate for sirtuins, PARPs, and CD38.
The aging story is real at the biological level. NAD+ levels fall in many tissues with age, and restoring them in old mice improves mitochondrial function, muscle performance, and some measures of healthspan. Most of that research used precursors such as nicotinamide riboside (NR) or nicotinamide mononucleotide (NMN), which cells can absorb and convert, rather than NAD+ itself. Human trials of those precursors reliably raise blood NAD+ but have shown modest or inconsistent functional benefits so far.
Direct NAD+ administration has much less data. A small Australian pharmacokinetic study of a six-hour intravenous infusion found plasma NAD+ did not rise until about two hours in, suggesting rapid uptake or breakdown, and that the infusion mainly raised nicotinamide and other metabolites. Oral NAD+ is largely broken down in the gut into precursors before absorption. Injected NAD+ probably works, if it works, by being converted to nicotinamide and rebuilt inside cells. The widespread IV clinic and injection use for fatigue, addiction recovery, and anti-aging rests on that plausible but unproven chain.
How it works
NAD+ accepts and donates electrons in glycolysis, the citric acid cycle, and fatty acid oxidation, cycling between NAD+ and NADH to keep the mitochondrial electron transport chain running. Separately from that redox role it is consumed as a substrate by sirtuins, which deacetylate proteins involved in stress resistance and mitochondrial biogenesis, by PARP enzymes that repair DNA, and by CD38, an enzyme that rises with inflammation and age and is a major cause of NAD+ decline. Raising NAD+ availability is thought to restore sirtuin and PARP activity and improve mitochondrial efficiency. Injected NAD+ is not transported intact into most cells; it is likely broken down outside cells into nicotinamide and nicotinamide riboside, which cells take up and rebuild into NAD+.
What the research shows
- rodentNAD+ levels decline with age in multiple human and mouse tissues, and restoring them in old mice improves mitochondrial function and muscle performance.
- human RCTOral NR and NMN reliably raise blood NAD+ in humans in randomized trials, with modest or inconsistent functional benefits.
- human pilotA six-hour intravenous NAD+ infusion in healthy volunteers did not raise plasma NAD+ until about two hours in, with rapid metabolism to nicotinamide and other products.
- rodentCD38 upregulation is a primary driver of age-related NAD+ decline in mice.
- rodentNAD+ precursors improved outcomes in mouse models of neurodegeneration and metabolic disease.
Evidence labels: rodent and in vitro mean no human data for that finding. Human pilot means small, often uncontrolled. Human RCT means randomized and controlled. Clinical means an approved drug with regulatory data.
Dose calculator
U-100 insulin syringeUnits are a volume on the syringe, not an amount of peptide. Concentration changes every time you change the water volume. The standalone calculator explains the math.
Dosing and protocol
Per injection, subcutaneous or intramuscular. IV clinics infuse 250 to 1000 mg over several hours. Oral NAD+ is mostly broken down before absorption; oral precursors like NR and NMN are used at 250 to 1000 mg daily.
Ongoing or in blocks of several weeks
Morning. Injections can cause a temporary energy dip or flush, so avoid late-day dosing.
| Vial | Suggested water | Concentration | Low dose draw |
|---|---|---|---|
| 500 mg | 5 mL | 100 mg/mL | 50 units |
| 1000 mg | 10 mL | 100 mg/mL | 50 units |
Lyophilized: fridge or freezer, away from light. Reconstituted: fridge 2-8C, use within 2 to 4 weeks. NAD+ degrades in solution faster than most peptides and the solution should stay clear and colorless.
Cautions
- ▲Injections sting and can cause redness, swelling, or a temporary flu-like feeling.
- ▲IV infusions given too fast cause chest tightness, nausea, cramping, and flushing; slow infusion is standard for that reason.
- ▲Large doses generate a lot of nicotinamide, which uses up methyl groups for clearance; the practical significance is debated.
- ▲Human evidence for functional benefit is far weaker than the marketing implies.
- ▲Compounded NAD+ quality varies and the solution degrades quickly; discolored vials should be discarded.
Commonly stacked with
MOTS-c signals through AMPK and mitochondrial pathways that depend on NAD+ availability.
SS-31 stabilizes the electron transport chain that NAD+ feeds electrons into.
Often infused together in clinics as a general antioxidant and energy combination.
Common longevity pairing of a coenzyme with a bioregulator peptide, without combined data.
Frequently asked
Is NAD+ a peptide?
No. It is a coenzyme made of two nucleotides. It gets grouped with peptides only because it is sold and injected the same way. Chemically and biologically it is unrelated to peptides.
Do injections work better than NMN or NR pills?
Nobody knows. Oral precursors have controlled trials showing they raise blood NAD+. Injected NAD+ has a small pharmacokinetic study and a lot of anecdote. Since injected NAD+ likely gets broken down to precursors before entering cells anyway, the advantage of injection over a good oral precursor is not established.
What does an NAD+ injection feel like?
Many people report a flush, mild nausea, or a wave of fatigue for 20 to 60 minutes after subcutaneous or intramuscular injection, followed by a sense of energy later in the day. Slower absorption from subcutaneous injection tends to be more comfortable than IM.
Why do IV infusions take hours?
Rapid NAD+ infusion causes chest pressure, cramping, and nausea, probably related to its breakdown products and effects on smooth muscle. Clinics drip it slowly over two to six hours to keep those symptoms tolerable.
Does it help with aging?
In mice, restoring NAD+ improves several aging markers. In humans, raising NAD+ is easy but showing it improves anything meaningful has been difficult. Treat anti-aging claims as hypothesis, not established benefit.
References
- A pilot study investigating changes in the human plasma and urine NAD+ metabolome during a 6 hour intravenous infusion of NAD+. Frontiers in Aging Neuroscience, 2019
- Therapeutic potential of NAD-boosting molecules: the in vivo evidence. Cell Metabolism, 2018
- NAD+ intermediates: the biology and therapeutic potential of NMN and NR. Cell Metabolism, 2018
- NAD+ metabolism and its roles in cellular processes during ageing. Nature Reviews Molecular Cell Biology, 2021