NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell, where it helps turn food into energy and powers enzymes involved in DNA repair.[1] It is now sold as IV drips and injections for energy and “anti-aging”, but a 2026 systematic review found no trials showing that injected or IV NAD+ improves any health outcome.[5] It is not FDA-approved as a drug.[15]

This profile covers what NAD+ does, what research shows for NAD+ injections and for the oral precursors NMN and NR, side effects, doses used in studies and the regulatory picture.

What is NAD+?

NAD+ is a helper molecule that cells use in hundreds of chemical reactions. It carries electrons in the reactions that release energy from food, and it is consumed by enzymes such as sirtuins, PARPs and CD38, which are involved in DNA repair, cell aging and immune function.[1]

Is NAD+ a peptide? No. It is built from vitamin B3 (niacin) and other components, not amino acids. It is often grouped with peptides because the same clinics and sellers offer both.

Why NAD+ is linked to aging

Studies in animals and people suggest NAD+ levels fall in some tissues with age, which led to the idea that topping it up could slow aging.[1] That idea is now contested: a 2026 study of seven groups of people found whole-blood NAD+ stayed remarkably stable with age and with lifestyle changes, rising only when people took a precursor supplement.[21][4] Even where NAD+ is low, raising it has not yet been shown to slow aging in people.[5]

NAD+ benefits: what the research shows

NAD+ injections and IV drips

Human research on giving NAD+ directly is small:

  • A 6-hour IV infusion of 750 mg in 8 healthy men raised blood NAD+ by about 400%, with no change for the first 2 hours.[2]

  • A wellness-clinic review of 500 mg IV NAD+ given on 4 days in a row tracked side effects and blood tests rather than benefits.[3]

  • No outcome trials: a 2026 systematic review of 33 human studies found no trials testing IV or injected NAD+ for anti-aging or wellness outcomes.[5] A separate 2026 review called IV “longevity therapy” an experimental intervention.[6]

  • A randomized pilot (not yet peer reviewed) found IV NAD+ caused more infusion discomfort than IV nicotinamide riboside, raised white blood cell counts, and left blood NAD+ lower at 3 hours than the NR infusion did.[24]

  • Heart failure trials in China: in 180 people with heart failure from coronary disease, 10 mg of IV NAD+ daily for 7 days modestly improved heart pumping (ejection fraction) at one month, but other outcomes were not significantly different.[22] In 60 older patients, 50 mg daily for 7 days did not produce statistically significant improvements.[23]

A trial comparing the discomfort of NAD+ injected under the skin, into muscle and by IV push was recruiting in 2026.[20]

NMN and NR supplements

NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are oral building blocks the body converts into NAD+. They have far more human data:

  • They raise NAD+. In a dose-ranging trial, NR raised whole-blood NAD+ by 22% to 142% within 2 weeks, depending on dose.[9] In a 2026 head-to-head study, NR and NMN raised blood NAD+ by a similar amount.[13]
  • Effects on health measures are mixed.
    • NMN improved muscle insulin sensitivity in women with prediabetes, but did not change weight, blood sugar or cholesterol.[11]
    • NR did not improve insulin sensitivity or body composition in obese men.[8]
    • A 2026 analysis of 15 NMN trials found no effect on weight, blood sugar, HbA1c or cholesterol.[14]
    • NR modestly improved walking distance in peripheral artery disease, which the authors said needs confirming.[19]
  • A large negative trial. In the 410-person NOPARK trial, a year of NR left people with early Parkinson’s disease slightly worse than placebo.[10]

NAD+ injections vs IV vs NMN and NR

IV dripInjection (under skin or into muscle)Oral NMN or NR
Human studiesOne small pilot plus a clinic review[2][3]Registered trials only, no results yet[20]Dozens of randomized trials[5]
Raises blood NAD+?Yes, after about 2 hours[2]Not yet measured in published studiesYes[9][13]
Typical side effectsStomach upset, chest pressure, flushing[3][4]Unknown in published studiesSimilar to placebo in most trials[14]

NAD+ side effects

  • During IV infusions: nausea and other stomach symptoms, cramping, flushing, a faster heart rate and chest pressure or discomfort.[3][4] Symptoms ended when the infusion stopped.[3]
  • Infusion speed seems to matter. No adverse events were reported during a slow 6-hour infusion in a small pilot, while faster clinic infusions caused more symptoms.[2][3] This is an observation across two studies, not a tested finding.
  • Oral NMN and NR were generally well tolerated; one NR trial reported occasional nausea, flushing, leg cramps and bruising.[7][14]
  • Contaminated products: FDA has warned that some compounders made IV NAD+ from food-grade ingredients and received reports of severe chills, shaking, vomiting and fatigue, some needing medical treatment.[25] In 2025, one company’s NAD+ injection was recalled for high levels of bacterial toxins.[26]
  • Supplements: Cleveland Clinic lists possible side effects of NAD+ supplements as nausea, headache, lightheadedness, diarrhea, muscle cramps and skin irritation, and advises people with cancer, liver disease, or who are pregnant or breastfeeding to talk to a provider first.[28]
  • Long-term safety of repeated NAD+ infusions or injections has not been studied.[4]

What users report

NAD+ research around the world

  • China: hospital trials have tested low-dose IV NAD+ in heart failure, with modest or non-significant results.[22][23] An injectable form called “Coenzyme I” is being tested in further Chinese trials.
  • Japan: single oral doses of NMN up to 500 mg caused no significant clinical symptoms in healthy men.[31]
  • Norway: the NOPARK trial, the largest and longest NR trial, found no benefit in Parkinson’s disease.[10]
  • Denmark: NR did not improve insulin sensitivity in obese men.[8]
  • Belarus: a 2026 Russian-language study found NAD+ precursors protected rats’ livers from alcohol damage. This was an animal study.[27]

NAD+ dosage: what has been studied

There is no established or approved dose of NAD+ for any use. These are the amounts used in published human studies:

FormDoses studied
IV NAD+750 mg over 6 hours[2]; 500 mg daily for 4 days[3]; 10 mg or 50 mg daily for 7 days in heart failure trials[22][23]
Injected NAD+100 mg under the skin, into muscle or by IV push (trial in progress)[20]
Oral NR500 mg twice daily[7][10]; up to 2,000 mg daily[8]
Oral NMN250 mg daily[11]; 300 to 900 mg daily[12]; up to 2,000 mg daily across trials[14]

For converting a vial’s milligrams into syringe units, see our peptide calculator.

  • Not FDA-approved as a drug for any condition.[15]
  • Compounding: FDA lists NAD in “Category 1”, substances it is still evaluating for use by compounding pharmacies.[15] In 2019 FDA proposed not allowing it, citing poor stability and a lack of safety data, but that proposal has not been finalized.[16]
  • NMN supplements: in September 2025 FDA reversed its 2022 position and accepted that NMN can be sold as a dietary supplement.[17]
  • Sport: NAD+ is not named on the World Anti-Doping Agency’s banned list, but WADA bans IV infusions of more than 100 mL in 12 hours outside hospital care, which covers typical NAD+ drips.[18]

This is general information, not legal advice.

NAD+ vs MOTS-c and other “longevity” compounds

NAD+ is often stacked with peptides such as MOTS-c. They work differently: NAD+ is a coenzyme used throughout the cell, while MOTS-c is a peptide signal made by mitochondria. Neither has outcome trials showing it slows aging in people.[5]