Name: NAD+
Brand: PeptidesDirect
SKU: PD-NADPLUS-1000MG
Availability: InStock

Question 1

What is NAD+?

Accepted Answer

NAD+ (Nicotinamide Adenine Dinucleotide) is a coenzyme present in all living cells. It plays a critical role in cellular energy metabolism, DNA repair, and gene expression. NAD+ levels naturally decline with age, making it a key focus in longevity research.

Question 2

How should I store NAD+?

Accepted Answer

Store lyophilized NAD+ at -20°C, light-protected and desiccated. After reconstitution, refrigerate at 2-8°C and use within 2 weeks. Protect from light and moisture.

Question 3

What purity is your NAD+?

Accepted Answer

Every batch of NAD+ ships with a certificate of analysis from Janoshik Analytical, an independent third-party laboratory, at a minimum purity of 99%. We do not run a lab ourselves: the manufacturer commissions this test, and we pass the report on unchanged, with an online verification link on the product page. This batch also carries a second, independent test from Freedom Diagnostics, commissioned outside the manufacturer.

Question 4

How do I reconstitute NAD+?

Accepted Answer

Add bacteriostatic water slowly along the vial wall. Gently swirl until dissolved - do not shake. Use the recommended volume of bacteriostatic water as indicated on the product label. The solution should be clear before use.

Question 5

How does NAD+ actually work in the body, according to research?

Accepted Answer

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme that accepts and donates hydride ions, shuttling electrons from food-derived metabolites into the mitochondrial electron transport chain to help generate ATP (Canto C et al., Cell Metab. 2015, PMID 26118927). The same molecule is also the required cosubstrate for sirtuins, which remove acetyl groups from proteins and histones, and for PARPs, which consume it to build ADP-ribose chains during DNA repair, so a cell's NAD+ pool gets used up by both energy metabolism and these signaling enzymes (PMID 26118927). It is not a hormone or a drug in the classic sense: it is a small nucleotide-based molecule, and its intracellular level is what injected or oral NAD+ boosting products are trying to raise.

Question 6

Is NAD+ a peptide?

Accepted Answer

No. A peptide is a short chain of amino acids joined by peptide bonds, while NAD+ is a dinucleotide built from nicotinamide and adenine linked through two ribose-phosphate units (PMID 26118927). It sits next to peptides in research catalogs, including ours, because it is handled and reconstituted the same way, lyophilized powder plus bacteriostatic water, not because it shares their chemistry. That distinction matters if you are reading mechanism-of-action literature: NAD+ studies concern coenzyme and redox biology, not amino acid sequences or peptide receptor binding.

Question 7

What has NAD+, given by injection or IV, actually been studied for?

Accepted Answer

Direct human evidence for injected or IV NAD+ itself covers exactly two small studies: an 8-person pharmacokinetic pilot in healthy men testing whether an IV infusion raises blood and urine NAD+ (Grant R et al., Front Aging Neurosci. 2019, PMID 31572171), and a 6-person retrospective chart review from a commercial IV clinic comparing tolerability to IV nicotinamide riboside (Reyna K et al., Front Aging. 2026, PMID 41704678). The only efficacy data for injected NAD+ are in rats, where a single IV dose protected the heart in a myocardial ischemia-reperfusion model (Zhang Y et al., Am J Transl Res. 2016, PMID 27648125). Everything else commonly cited as "NAD+ research," including a Parkinson's disease trial and a healthy-adult safety trial, actually dosed the oral precursors nicotinamide riboside or nicotinamide mononucleotide, not injected NAD+ itself (PMID 35235774, PMID 35479740).

Question 8

What dose of NAD+ did the studies use, and is there a real human dosing protocol?

Accepted Answer

The only per-kilogram dose anywhere in the NAD+ literature comes from rats: in a myocardial ischemia-reperfusion model, adult male Wistar rats received a single intravenous dose of 5, 10 or 20 mg per kg immediately before the ischemia was induced (Zhang Y et al., Am J Transl Res. 2016, PMID 27648125). Human studies used absolute IV doses only, not weight-based ones: 750 mg, run at 3 micromol per minute, as a single 6 hour infusion in one small pharmacokinetic pilot (Grant R et al., Front Aging Neurosci. 2019, PMID 31572171), and 500 mg once daily for 4 consecutive days in a retrospective clinic chart review (Reyna K et al., Front Aging. 2026, PMID 41704678). Neither human study reported individual body weights, so a per-kg human figure cannot be derived from either one, and no human dosing protocol for injected or IV NAD+ has been published anywhere in the literature.

Question 9

How fast does NAD+ actually work, based on the studies?

Accepted Answer

In the human pharmacokinetic pilot, nothing measurable happened for the first two hours of the infusion: plasma NAD+ and its metabolites did not rise until the 6 hour timepoint, where plasma NAD+ was up about 398% and urinary NAD+ excretion was up about 538% (Grant R et al., Front Aging Neurosci. 2019, PMID 31572171). The authors read that delay as evidence that most infused NAD+ is broken down or taken up by tissue before it can be measured intact in blood, a slower and less direct picture than IV NAD+ marketing implies. In the rat heart study, a single dose given right before the ischemic injury produced a dose-dependent effect within the 24 hour reperfusion window, with the 20 mg/kg dose cutting infarct size by roughly 85% (Zhang Y et al., Am J Transl Res. 2016, PMID 27648125), but that is a rodent surrogate endpoint from one study, not a human clinical outcome.

Question 10

What side effects has IV NAD+ actually caused in studies?

Accepted Answer

In the retrospective chart review, all 6 people who received 500 mg NAD+ IV once daily for 4 days had moderate to severe symptoms: abdominal cramping, diarrhea, nausea, vomiting, raised heart rate, throat pain and chest pressure during the infusion, and the infusion had to be run about 60% slower on average, 97 minutes versus 37 minutes for the nicotinamide riboside comparator arm, to be tolerated (Reyna K et al., Front Aging. 2026, PMID 41704678). In the other human study, an 8-person single 6 hour infusion, no adverse events were reported at all, only minor and clinically insignificant liver-enzyme shifts (Grant R et al., Front Aging Neurosci. 2019, PMID 31572171). All symptoms in the Reyna cohort resolved once the infusion finished, but that study had no placebo arm and several of its authors were employed by the commercial IV clinic where it was run, a real conflict of interest worth stating plainly rather than smoothing over.

Question 11

Can NAD+ IV infusions damage your liver or affect your cholesterol?

Accepted Answer

In the two available human studies, liver enzymes stayed within the normal range: the pharmacokinetic pilot saw only minor, clinically insignificant shifts (GGT, LD and AST fell slightly, bilirubin rose slightly), and the retrospective chart review found ALT and AST unchanged, with alkaline phosphatase falling slightly but staying in range (Grant R et al., PMID 31572171; Reyna K et al., PMID 41704678). Neither study found evidence of liver damage, but the same retrospective review did find a significant fall in HDL cholesterol in the NAD+ group, a real signal that has not been explained or followed up. Both findings come from a combined total of 14 people across two small, short studies, so this rules out nothing about a liver or lipid effect over longer or repeated use, it only says none was seen in these two short studies.

Question 12

What don't we know about NAD+'s long-term safety?

Accepted Answer

There is no large, randomized, placebo-controlled human trial of injected or IV NAD+ itself: the entire direct human evidence is one 8-person pharmacokinetic pilot (PMID 31572171) and one 6-person retrospective chart review with a stated conflict of interest and only 30 days of follow-up (PMID 41704678), so nothing has been published about repeated cycles, use beyond a month, or long-term risk. No study has reported individual body weights for human NAD+ dosing, so there is no validated per-kilogram human protocol at all, only the empirical 250 to 1,000 mg clinic "drip" doses and the two absolute doses cited above. Both human studies together cover 14 people, which is not enough to detect an uncommon side effect or a slow-developing one.

Question 13

Does raising your NAD+ level actually do anything, or does it just move a lab number?

Accepted Answer

Raising blood NAD+ is well documented, but that a raised NAD+ level produces a meaningful clinical benefit is not established. A nicotinamide riboside trial in long COVID missed its primary cognitive endpoint despite a 2.6 to 3.1 fold rise in blood NAD+ (Wu CY et al., EClinicalMedicine. 2025, PMID 41357333), and a meta-analysis in adults over 60 found no benefit to muscle mass, strength or physical performance from NMN or NR supplementation (PMID 40275690). Both of those disappointing results are for oral precursors, which have more human outcome data behind them than injected NAD+ does, so the injected form carries even less proof of a functional benefit, not more.

Question 14

Is NAD+ approved by the FDA, EMA, or any regulator?

Accepted Answer

No regulator, not the FDA, the EMA, nor any other national medicines agency, has approved NAD+, injected or oral, as a drug for any medical condition. Every study cited here is an investigator-led pilot, a retrospective chart review, or a small phase 1 trial, not a registration study submitted for approval, and the clinic "drip" doses common in IV lounges (250 to 1,000 mg) are empirical practice, not a regulator-reviewed protocol. A marketing claim that IV NAD+ is "clinically proven" or "FDA registered" should be read as false: no such registration exists in the current published record.

Question 15

What does your own lab report actually show for NAD+?

Accepted Answer

Our current batches carry two manufacturer-commissioned Janoshik reports: the 500 mg batch, labelled Green, tested at 99% purity with 486.17 mg of NAD+ content, and the 1,000 mg batch, labelled Black, tested at 99% purity with 973.65 mg content, both checkable against the vial's batch code at verify.janoshik.com. A separate 1,000 mg batch, Lot 51926, carries a community-submitted report from Freedom Diagnostics at 99.8% purity and 989.45 mg content, checkable through Freedom Diagnostics' own verification portal. Janoshik is commissioned and paid for by the manufacturer, not by us, and the Freedom Diagnostics report was submitted by a customer rather than commissioned by either of us, so all three are third-party lab data, not our own independent testing.

Question 16

Is NAD+ the same thing as NMN or NR?

Accepted Answer

No. NAD+ is the finished coenzyme, while NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are smaller precursor molecules that the body converts into NAD+ through the salvage pathway (Canto C et al., Cell Metab. 2015, PMID 26118927). They are studied differently too: NMN and NR are given as oral tablets and have more human trial data behind them, a Parkinson's disease trial for NR (PMID 35235774) and a 12 week healthy-adult safety trial for NMN (PMID 35479740), while NAD+ itself is what gets injected or infused directly, with far less direct human study. A study result for oral NR or NMN is not evidence about what an injected NAD+ vial does, and the reverse is also true.

Question 17

Is injectable NAD+ or an oral precursor like NMN or NR better supported by research?

Accepted Answer

Oral precursors have the stronger human evidence: NR raised cerebral NAD levels and was well tolerated in a 30-person Parkinson's disease phase 1 trial (Brakedal B et al., NADPARK, Cell Metab. 2022, PMID 35235774), and 250 mg per day of NMN safely raised whole-blood NAD+ over 12 weeks in 30 healthy adults with no notable adverse events (Okabe K et al., Front Nutr. 2022, PMID 35479740). Injected NAD+ itself has only two small human studies, one showing a delayed and modest pharmacokinetic rise (PMID 31572171) and one showing that all 6 recipients had moderate to severe infusion-related symptoms (PMID 41704678), so the injected form is less studied in humans and had a rougher tolerability signal than the oral precursors did. Neither route has a large randomized trial proving a clinical benefit, so more human data for the precursors is not the same as proof that they work.

Question 18

Does a single NAD+ infusion work differently than doing it daily for several days?

Accepted Answer

The two available human studies used opposite schedules: the pharmacokinetic pilot gave a single continuous 6 hour infusion totalling roughly 750 mg (Grant R et al., Front Aging Neurosci. 2019, PMID 31572171), while the retrospective chart review used a 4 day loading protocol of 500 mg once daily (Reyna K et al., Front Aging. 2026, PMID 41704678). No adverse events were reported after the single infusion, while all 6 recipients of the repeated 4 day schedule had moderate to severe symptoms and needed a slower infusion rate, though the two studies differ in so many other ways, sample size, setting, monitoring, that this is an observation, not a controlled comparison of schedules. Nobody has run a trial that varies only the schedule while holding everything else constant, so whether single-dose versus repeated dosing is actually what drives the tolerability difference is not established.

Question 19

How much bacteriostatic water should be used to reconstitute a 500 mg or 1,000 mg NAD+ vial?

Accepted Answer

Our NAD+ vials (500 mg and 1,000 mg) follow the same reconstitution approach as our other lyophilized peptides: bacteriostatic water added slowly down the inside wall of the vial, then swirled gently, never shaken. The water volume is a concentration choice: more water gives a more dilute mg per mL solution, less gives a more concentrated one, and it does not change the vial's total NAD+ content. Because NAD+ is chemically less stable in solution than most of our other lyophilized peptides, preparing a smaller working volume closer to use, rather than dissolving a full vial at once, is a sensible precaution. No published protocol specifies an exact water-to-NAD+ ratio, so this is standard lab-solution practice, not a study finding.

Question 20

How long does reconstituted NAD+ remain stable in solution, and should it ever be frozen?

Accepted Answer

NAD+ is markedly less stable once dissolved than its precursors NMN and NR, or most of the lyophilized peptides in our catalogue, it degrades faster in aqueous solution, especially at room temperature or under light. Keep reconstituted NAD+ refrigerated at 2 to 8°C, protected from light, and do not freeze the solution, since a freeze-thaw cycle stresses an already less stable molecule further. Rather than relying on a fixed day count (a 28-day figure sometimes quoted by IV clinics is not something we can verify against any published stability study for injected NAD+), the more honest approach is to prepare a smaller working volume and use it promptly rather than keeping a full vial dissolved for weeks.

Question 21

Does NAD+ cross into cells intact, or does it need to break down into precursors first?

Accepted Answer

This is genuinely debated in the research literature. NAD+ is a comparatively large, negatively charged dinucleotide, and simple diffusion across an intact cell membrane is not straightforward for a molecule that size and charge. Some proposed routes involve cell-surface enzymes breaking NAD+ down into nucleosides or nicotinamide before uptake and resynthesis inside the cell, while other work points to dedicated membrane transporters that may move NAD+ more directly, and neither mechanism is settled as the dominant one. This is exactly why we keep NAD+ and its precursors, NMN and NR, in separate FAQ answers on this page: the extracellular-to-intracellular step is a real, unresolved variable, not a detail that can be glossed over.

Question 22

Why does a lyophilized NAD+ vial sometimes look almost empty? Does that mean it was underfilled?

Accepted Answer

No. Lyophilized (freeze-dried) powder in the milligram quantities used per vial can look like almost nothing, a thin film, a light dusting, or a few flakes clinging to the glass wall, rather than a visible mound of powder. That is a normal property of the freeze-drying process for a molecule like NAD+, not evidence that a vial was underfilled. Visual inspection cannot tell you how much NAD+ is actually in a vial either way: the only real verification is the batch's Certificate of Analysis, which states the measured content in milligrams and is checkable against the vial's batch code on our lab reports page.

Question 23

How is NAD+ level or activity actually measured in a research study, and does the method matter for reading results?

Accepted Answer

Two assay families dominate the published NAD+ literature. Enzymatic cycling assays use kits that convert NAD+ and NADH into a colorimetric or fluorescent signal proportional to concentration, and are the more common, lower-cost method in cell and tissue studies. Isotope-labeled mass spectrometry, liquid chromatography paired with stable-isotope internal standards, is the more precise method, able to distinguish NAD+ from NADH and related metabolites directly rather than through an enzymatic proxy, and is the approach a study reaches for when those metabolites need to be told apart. The method matters because cycling assays can be sensitive to sample handling and can conflate related metabolites, so results across different studies are not always directly comparable.

Question 24

Is NAD+ (oxidized) the same molecule as NADH (reduced), and does the distinction matter for research use?

Accepted Answer

NAD+ and NADH are not different molecules, they are the oxidized and reduced forms of the same coenzyme, the way a charged and a discharged battery are still the same battery. NAD+ accepts electrons to become NADH, and NADH donates them back to become NAD+ again, and that cycling is the whole basis of its role in cellular energy metabolism. Our vials contain the oxidized form, NAD+, which is also the form given in the injected NAD+ studies cited in our other FAQ answers here, not the reduced NADH. The distinction matters for reading the literature: a study reporting an NAD+ to NADH ratio is measuring redox balance, not comparing two different research compounds.

Question 25

Does raising NAD+ levels increase cancer risk, since sirtuins and the NAD+ salvage pathway that support DNA repair in healthy cells are also upregulated by many tumors to fuel their own growth?

Accepted Answer

Sirtuins and the NAD+ salvage pathway support DNA repair and energy metabolism in healthy cells, and the same pathway is well documented to be upregulated in many tumor types, where it feeds the same DNA-repair and metabolic machinery for cancer cells, not just healthy ones. That overlap is real and unresolved, not reassuring in either direction: neither of the two published human NAD+ studies (Grant R et al., Front Aging Neurosci. 2019, PMID 31572171; Reyna K et al., Front Aging. 2026, PMID 41704678) enrolled cancer patients, measured a cancer-related outcome, or followed anyone beyond 30 days. Whether raising NAD+ changes cancer risk in someone without cancer has not been tested and is not settled by the existing literature.

Question 26

Do the widely reported NAD+ side effects (flushing, nausea, chest tightness) apply the same way to a subcutaneous or intramuscular research solution as to the clinic IV infusions most published content describes?

Accepted Answer

All published human safety data on NAD+ itself comes from intravenous administration. The 8-person pharmacokinetic pilot ran a single 6-hour IV infusion (Grant R et al., Front Aging Neurosci. 2019, PMID 31572171), and the 6-person retrospective chart review dosed NAD+ IV once daily for 4 days in a commercial IV clinic, where cramping, nausea, vomiting, raised heart rate and chest pressure were reported and the infusion had to be slowed to be tolerated (Reyna K et al., Front Aging. 2026, PMID 41704678). No published human study has given NAD+ subcutaneously or intramuscularly, so there is no comparable systemic side-effect data for those routes. Most public "NAD+ side effects" content, in clinic marketing and forums, describes that IV protocol, not a reconstituted research vial, and the two cannot be assumed to behave the same way.

NAD+

What is NAD+

How it works

Often studied alongside

Documentation

Storage and stability

Frequently Asked Questions

Technical data sheet

Frequently bought together

MOTS-c

SS-31

Epitalon

Bacteriostatic Water

Lab Measuring Syringe + Prep Wipes Set (1 mL 31G)

Graduated Measuring Syringe 1 mL 31G x 6 mm

Alcohol Prep Pads 30 x 65 mm

Peptide Storage Box (10 Compartments)

Peptide Vial Case 30 Slots