NAD+

What is NAD+

NAD+ stands for nicotinamide adenine dinucleotide in its oxidized form. It is not a peptide, but an endogenous coenzyme found in every cell of the human body. NAD+ is central to energy metabolism, DNA repair and sirtuin activity associated with longevity mechanisms.

Structurally, NAD+ consists of two nucleotides (adenine and nicotinamide), connected via a phosphate bridge. Molecular weight: 663.43 g/mol. CAS No: 53-84-9.

The NAD+ concentration in the cells decreases with age. This observation has fueled a large research and supplement market, ranging from Oral precursors (NMN, NR) to intravenous NAD+ infusions. The data is solid in terms of the biochemical role, but gaps in clinically relevant effects in healthy adults.

Mechanism of action

NAD+ works on several levels:

First, as a coenzyme in redox reactions in energy metabolism. The conversion of NAD+ to NADH and back drives glycolysis, citrate cycle and respiratory chain. Low NAD+ levels limit ATP production.

Second, as a substrate for sirtuins (SIRT1 to SIRT7), a family of enzymes that deacetylate histones and other proteins. Sirtuins are associated with longevity, stress resistance and metabolic regulation. Without NAD+, sirtuins cannot work.

Thirdly, as a substrate for PARP enzymes that mediate DNA repair. Chronic DNA damage consumes NAD+ via PARP activity, further lowering levels.

Fourth, as a substrate for CD38, an NAD+-consuming enzyme that becomes more active with age. This activity is one of the main reasons for the decline in age of NAD+.

When administered intravenously, NAD+ is introduced directly into the circulation, but uptake into the cells is controversial. NAD+ is polar and large, the cell membrane is a significant barrier. More likely is uptake via precursors such as nicotinamide and nicotinic acid after extracellular degradation.

Areas of application in research

Anti-aging and Longevity: Main motivation of current research
Mitochondrial dysfunction: Energy problems, chronic fatigue
Neurodegeneration: Parkinson's disease, Alzheimer's disease (early studies)
Addiction withdrawal: NAD+ infusions are used in some clinic programs
Sports Recovery: Off-label application
Skin ageing: Topical applications in cosmetics

Study situation

The biochemical basis is very well established. Clinical data on supplementation and infusions are thinner and predominantly concentrated in Oral precursors (NMN, NR).

Important works:

Sinclair Group: many works on the NAD+ Sirtuin axis, establishes the Longevity concept (e.g. Imai & Guarente, Trends in Cell Biology, 2014
Yoshino et al. (Cell Metabolism, 2018): NMN in mice, broad effects on glucose tolerance and mitochondrial function
Martens et al. (Nature Communications, 2018): NR in older adults, significant increase in NAD+ levels, marginal clinical effects
Yoshino et al. (Science, 2021): NMN in prediabetic women, improved muscle insulin sensitivity
Brakedal et al. (Cell Metabolism, 2022): NR in Parkinson’s patients, positive effect on symptoms

In the case of intravenous NAD+ infusions, the controlled data is very limited. Most of the data comes from clinical observations and small uncontrolled studies.

What is clear: NAD+ is biochemically important, falls with age, and precursors increase NAD+ levels reproducibly. What remains unclear is whether this increase translates into clinically relevant outcomes, and whether intravenous NAD+ administration makes sense compared to Oral precursors.

Mixing (reconstitution)

NAD+ is often offered as a powder or premixed solution. For injectable application typical sizes 100 mg, 500 mg, 1000 mg vials.

500 mg Vial with 5 ml sterile water → 100 mg/ml
1000 mg Vial with 10 ml → 100 mg/ml for infusions

In IV application, 0.9 percent is typically diluted in 100 to 500 ml of NaCl and infused slowly. Subcutaneously possible, but because of volumes mostly impractical.

Storage: cooled, dark. Stability as a dry powder well, usually dissolved in the refrigerator for 2 to 4 weeks.

Dosage range (research data)

Intravenous use in clinics:

250 mg to 1500 mg per session
Infusion for 2 to 4 hours (rapid infusion leads to very unpleasant side effects)
Frequency: 1 to 5 sessions per treatment cycle
Repeat: every 4 to 12 weeks

Subcutaneous in the research use community:

50 to 100 mg per day
Frequency: daily or every other day

Oral precursors (NMN, NR):

NMN: 250 to 1000 mg per day
NR: 250 to 1000 mg per day

These values are research and clinic references, unapproved therapy protocols.

Side effects

In the case of intravenous administration with too fast infusion:

Very unpleasant breast
Nausea
Hot flashes
Headache
Muscle cramps
Increased blood pressure

These effects are largely avoidable by slow infusion (at least 2 hours).

For Oral precursors:

Very well tolerated in most studies
Rare nausea, flushing, headaches
Theoretically questionable: increased consumption of methyl groups (NAD+ metabolism consumes SAM-e), but not relevant in studies

For subcutaneous NAD+ application:

Local irritation at the injection site
Temporary fatigue or warmth

Long-term safety with continuous high-dose application not established.

Half-Life and Pharmacokinetics

NAD+ itself has a very short half-life in plasma, in the range of minutes, because it is rapidly degraded to nicotinamide and other metabolites. These metabolites are then absorbed by cells and rebuilt intracellularly into NAD+ (Salvage Pathway).

The effect of IV-NAD+ is presumably indirect via the elevated plasma levels of the precursors, not directly via NAD+ uptake in cells.

Oral NAD+ supplementation is controversial in terms of bioavailability. NMN and NR are more effective here because they have better recording and conversion pathways.

Frequent questions

Do I need IV or is it enough Orally? In most healthy adults, Oral precursors (NMN or NR) are sufficient for NAD+ elevation. IV sessions are more expensive, more time-consuming and the added value is not clearly proven. Addiction withdrawal programs use IV-NAD+ at higher doses for clinical anecdotal reasons.

How fast does NAD+ work? Biochemically, NAD+ levels increase within hours to days. Subjective effects (energy, clarity) some users report within the first session, others only after several weeks.

Why is the IV so unpleasant on fast infusion? Direct effect on vascular receptors and very fast methylation load. Slow infusion over 2 to 4 hours is standard.

How much does a NAD+-IV in Germany cost? Private service, typically 250 to 600 euros per session depending on the clinic and dose. Packages (5 to 10 sessions) cheaper per unit.

NMN, NR, NAD+: what to take? NMN and NR are Oral, well tolerated, evidence-based. NAD+ directly makes little sense Orally (degradation in the GI tract), IV is the only meaningful form.

Legal status U.S.

As of 2026: NAD+ is not approved as a medicine in Germany. IV-NAD+ treatments are offered in private clinics, in a legal grey area. The substance itself is not prescription, but medical use on humans should be done by a licensed doctor.

NMN is not yet approved in the EU as a novel food. Selling as a dietary supplement in the EU market is therefore legally problematic, even if many online shops ignore this.

NR is available as a ChromaDex licensed product (Niagen) as a dietary supplement in some EU markets.

WADA status: NAD+ and precursors are not on the prohibited list.

Related compounds

NMN (nicotinamide mononucleotide)Direct NAD+ precursor, Oral bioavailability
NR (nicotinamide-riboside)Other NAD+ precursors
nicotinic acid (niacin)Classical precursor, with flushing effect
nicotinamide: Precursor, without flushing
resveratrolSirtuin activator, often combined
5-Amino-1MQNNMT inhibitor, indirect NAD+ increase

Note: All information is for research information only. These peptides are not approved as medicines in Germany. The contents do not replace medical advice. Application to humans is not legally covered in Germany.