In the US, IV NAD+ has no FDA-approved use. The authors of a 2019 study, one of them a wellness clinic's medical director, cite earlier reports of benefit from IV NAD+ in alcohol withdrawal. FDA, reviewing NAD for fatigue in multiple sclerosis, found no published studies supporting that use. In China, an injectable NAD+ product sold in 5 mg vials lists coronary heart disease and myocarditis on its package insert.

Benefits and uses

NAD+ benefits and uses

No human study of NAD+ injections reviewed here shows better energy, memory or slower aging, and the authors of a 2026 study call human data on IV NAD+ limited.¹ The injection studies measured blood levels and tolerability in groups of 4 to 8 people.²¹³ Oral NR raised blood NAD+ in trials, but a 2023 review found few clinically relevant effects.⁴⁵

This page summarizes published sources for information only. It is not medical advice and does not tell anyone to use a product. Questions about your own health belong with a licensed clinician. For questions about an order or a product, contact us.

Why NAD+ draws interest

NAD+ is an electron carrier at the center of energy metabolism, and enzymes studied in aging research, such as sirtuins and PARPs, depend on it.⁹ Lower NAD+ also correlates with older age in rodents and people.⁹ In skin samples from 49 people, from newborns to age 77, NAD+ was lower at older ages in both males and females.¹⁰ A link like this cannot show whether low NAD+ causes aging or simply accompanies it, and it says nothing about whether adding NAD+ helps. A 2020 review noted that the preclinical benefits of NAD+ therapy still need to be reproduced in human trials.¹¹

What human studies of NAD+ injections measured

Study	People	What was given	What was measured	Result
2019 randomized pilot	11 healthy men aged 30 to 55 (8 NAD+, 3 saline)	750 mg IV over 6 hours, once	Plasma and urine NAD+ metabolites	No plasma rise for at least 2 hours, 398% above baseline only at 6 hours; no adverse events²
2026 retrospective review	14 clinic clients (6 NAD+, 8 NR)	500 mg IV daily for 4 days	Tolerability, liver enzymes, hsCRP	All 6 NAD+ clients reported moderate to severe symptoms during infusion; liver enzymes stable or lower and hsCRP unchanged at 30 days¹
2026 preprint, trial 1 of two pilots (not peer reviewed)	45 adults in 9 groups, 4 to 6 per NAD+ group	100 mg by IV push, or by intramuscular or subcutaneous injection	Safety and tolerability	No attributable unexpected adverse events³
NCT06382688 (registered, randomized, placebo-controlled)	53 healthy adults aged 40 or older	500 mg IV in 500 mL saline	Blood NAD, infusion time, and energy and sleep scales	No results posted on the registry¹²
NCT06558253, a phase 1 trial in China	Adults with blood cancers after a cord blood transplant	10, 20 or 50 mg IV daily for 21 days	Safety, then recovery of blood cell production	Listed as recruiting at its last update (December 2024); no results¹³

None of these studies has reported a health benefit. A rise in plasma NAD+ is a lab marker. Because NAD+ cannot cross cell membranes on its own, a higher blood level does not by itself show more NAD+ inside cells.²

Goals people search for

Energy and aging

One randomized, placebo-controlled trial of IV NAD+ (NCT06382688) listed an energy scale among its outcomes, but no results are posted on its registry record.¹² No other study reviewed here tested NAD+ injections for energy or aging. The 2026 clinic review's authors describe the human efficacy data for IV NAD+ as limited.¹ The case for these goals rests on cell and animal biology, which a 2020 review said still has to be confirmed in human trials.¹¹

Memory and focus

No trial in these sources tested NAD+ injections for memory or thinking. In a 2025 phase 2 pilot of oral nicotinamide riboside, 52 older adults with amnestic mild cognitive impairment were randomized to NR or placebo for 12 weeks. NR was well tolerated, but cognitive function did not significantly improve; the trial was reported as a conference abstract.¹⁴ Related: Peptides and focus and memory.

Weight and body composition

No NAD+ injection study in these sources tested effects on body weight. In precursor trials, 10 weeks of oral NMN produced no change in body weight or body fat among 25 women with prediabetes.¹⁵ Oral NR at 2,000 mg a day for 12 weeks did not alter body composition in 40 obese men.¹⁶ Related: Peptides and weight loss.

Blood sugar

Results are mixed and come only from oral precursors. NMN for 10 weeks raised muscle insulin sensitivity by 25% (plus or minus 7%) in 25 women with prediabetes, with no change on placebo.¹⁵ NR at 2,000 mg a day for 12 weeks did not improve insulin sensitivity in 40 obese, insulin-resistant men.¹⁶ NAD+ injections have not been tested for blood sugar control in these sources. Related: Peptides and blood sugar.

Muscle and exercise

In 80 healthy adults aged 40 to 65, oral NMN taken for 60 days increased six-minute walk distance more than placebo.¹⁷ Two companies, Aba Chemicals and Abinopharm, fully funded that trial.¹⁷ A 2023 review found that human NR studies have not replicated animal findings of better muscle mitochondrial function.⁵ Related: Peptides and muscle growth.

Sleep

The NAD+ injection studies reviewed here did not report sleep outcomes. A registered trial comparing IV NAD+ with IV NR listed a sleep scale among its measures, but no results are posted on its registry record.¹² Related: Peptides and sleep.

Alcohol withdrawal and other uses

The authors of the 2019 pilot cite earlier reports of benefit from IV NAD+ in alcohol withdrawal.² One of them is medical director of a clinic that uses IV NAD as therapy.² No controlled trial of that use was found for this page. FDA reviewed NAD for fatigue in multiple sclerosis and found no published studies supporting it.⁷ In China, an approved injectable NAD+ product in 5 mg vials lists coronary heart disease and myocarditis on its package insert. A 2026 trial protocol plans to test it in children with heart dysfunction; the trial was not yet recruiting at its September 2026 update.⁸

How to weigh these findings

Small and brief. The injection studies had 4 to 8 people per NAD+ group. The two IV studies gave NAD+ once or on 4 days.²¹³
Markers, not outcomes. In 140 adults, higher daily amounts of oral NR produced higher whole-blood NAD+.⁴ Yet a 2023 review of human trials found few clinically relevant effects.⁵
Industry ties. A wellness clinic funded the 2026 review of its own records.¹ ChromaDex funded the first trial in the 2026 preprint, which tested its Niagen NR product.³
Peer review. The 2026 injection-route data come from a preprint that has not been through journal review.³

Related pages: NAD+ side effects, NAD+ dosage and How to reconstitute NAD+. Back to the overview: What is NAD+?

NAD+ in the store

NAD+

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Frequently asked questions

Is NAD+ really worth it?

The evidence does not yet show a benefit. Human studies of NAD+ injections were small blood-level or tolerability studies: 8 men in a 2019 pilot, 6 clinic clients in a 2026 review.²¹ The authors of the 2026 review add that human data on the efficacy and health effects of IV NAD+ remain limited.¹ For oral precursors, a 2023 review of human trials found few clinically relevant effects of nicotinamide riboside.⁵

What do NAD injections do to your body?

So far, studies have measured blood chemistry and tolerability, not health outcomes. In a 2019 pilot, NAD+ infused at 750 mg over 6 hours was cleared from plasma rapidly and completely for at least the first 2 hours, and plasma NAD+ rose 398% only at the 6 hour mark.² NAD+ carries a negative charge and cannot cross cell membranes on its own, so a higher blood level does not by itself show more NAD+ inside cells.²

What is NAD+ IV for?

In the US, IV NAD+ has no FDA-approved use.⁶ The authors of a 2019 study, one of them a wellness clinic's medical director, cite earlier reports of benefit from IV NAD+ in alcohol withdrawal.² FDA, reviewing NAD for fatigue in multiple sclerosis, found no published studies supporting that use.⁷ In China, an injectable NAD+ product sold in 5 mg vials lists coronary heart disease and myocarditis on its package insert.⁸

How long does it take for NAD IV to work?

None of the studies reviewed here reported a health benefit, so there is no timeline for one. The only timing data concern blood levels. In 8 healthy men given 750 mg over 6 hours, plasma NAD+ did not rise for at least the first 2 hours and was raised only at the 6 hour point.² That pilot measured blood and urine chemistry and adverse events, not energy, mood or other effects people notice.²

Written by D2C Peptides Editorial Team.

Pending qualified review.

Updated October 25, 2026.

Sources

Intravenous infusion of nicotinamide adenine dinucleotide (NAD+) versus nicotinamide riboside (NR): a retrospective tolerability pilot study in a real-world setting (Reyna et al.): adverse experiences. Frontiers in Aging (via PMC), 2026.
A Pilot Study Investigating Changes in the Human Plasma and Urine NAD+ Metabolome During a 6 Hour Intravenous Infusion of NAD+ (Grant et al.): design and safety. Frontiers in Aging Neuroscience (via PMC), 2019.
Preliminary Safety Analysis of Two Pilot Clinical Trials Involving Injections of Niagen, Nicotinamide Riboside Chloride (Nkrumah-Elie et al., preprint): route comparisons. medRxiv (preprint server), 2026.
Safety and Metabolism of Long-term Administration of NIAGEN (Nicotinamide Riboside Chloride) in a Randomized, Double-Blind, Placebo-controlled Clinical Trial of Healthy Overweight Adults (Conze et al.). Scientific Reports (via PMC), 2019.
What is really known about the effects of nicotinamide riboside supplementation in humans (Damgaard and Treebak). Science Advances (via PMC), 2023.
Bulk Drug Substances Nominated for Use in Compounding Under Section 503B of the Federal Food, Drug, and Cosmetic Act (updated March 21, 2025). U.S. Food and Drug Administration, 2025.
Amendments to the List of Bulk Drug Substances That Can Be Used to Compound Drug Products in Accordance With Section 503A (proposed rule, 84 FR 46688, September 5, 2019): NAD evaluation. Federal Register (U.S. FDA), via govinfo.gov, 2019.
NCT07839130: The PEDI-NAD Trial: Injectable NAD+ for Pediatric Cardiac Dysfunction (product description). ClinicalTrials.gov, U.S. National Library of Medicine, 2026.
NAD+ metabolism and its roles in cellular processes during ageing (Covarrubias et al.): coenzyme roles. Nature Reviews Molecular Cell Biology (via PMC), 2021.
Age-Associated Changes In Oxidative Stress and NAD+ Metabolism In Human Tissue (Massudi et al.). PLoS One (via PMC), 2012.
NAD+ therapy in age-related degenerative disorders: A benefit/risk analysis (Braidy and Liu). Experimental Gerontology (PubMed abstract via NCBI E-utilities), 2020.
NCT06382688: Randomized, placebo-controlled trial comparing IV Niagen (nicotinamide riboside chloride) with IV NAD+ in healthy adults (arms and outcomes). ClinicalTrials.gov, U.S. National Library of Medicine, 2024.
NCT06558253: Coenzyme I for Injection in Promoting Hematopoietic Recovery After Single-unit Cord Blood Transplantation. ClinicalTrials.gov, U.S. National Library of Medicine, 2024.
A phase-II randomized controlled pilot and feasibility study of nicotinamide riboside supplementation in older adults with amnestic mild cognitive impairment (Martens et al., conference abstract). Alzheimer's & Dementia (via PMC), 2025.
Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women (Yoshino et al.). Science (via PMC author manuscript), 2021.
A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects (Dollerup et al.). American Journal of Clinical Nutrition (PubMed abstract via NCBI E-utilities), 2018.
The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults (Yi et al.): outcomes. GeroScience (via PMC), 2023.