# NAD+ References: The Studies Behind Every Claim | NAD+

> Every NAD+ claim on this site, sourced. The full reference list — randomized trials, mechanistic reviews and preclinical studies on NAD+, NMN and NR — with DOIs and PubMed links.

The full source list behind this digest — the randomized human trials, the mechanistic reviews, and the preclinical studies on NAD+ and its precursors, each with a DOI or PubMed link.

## How to read this list

Every numbered citation here is referenced by a `[N]` marker somewhere on the site. Randomized human trials and mechanistic reviews carry the most weight; entries marked as mouse or in-vitro work are preclinical and labelled as such in the body text. Where a study used a precursor (NMN, NR or nicotinamide) rather than NAD+ itself, the body text says so — because, as the rest of this site keeps insisting, an oral-NMN trial is not the same thing as "taking NAD+." Identifiers — DOI, PMID — are given so any claim can be traced to its source. The 2025 *Nature Metabolism* review [15] is the single best entry point if you want the current honest read on where the human evidence stands.

## References

[1] Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224-1229. https://pubmed.ncbi.nlm.nih.gov/33888596/
[2] Camacho-Pereira J, Tarragó MG, Chini CCS, et al. CD38 Dictates Age-Related NAD Decline and Mitochondrial Dysfunction through an SIRT3-Dependent Mechanism. Cell Metab. 2016;23(6):1127-1139. https://pubmed.ncbi.nlm.nih.gov/27304511/
[3] Yi L, Maier AB, Tao R, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. GeroScience. 2023;45(1):29-43. https://pubmed.ncbi.nlm.nih.gov/36482258/
[4] Conze D, Brenner C, Kruger CL. 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. Sci Rep. 2019;9(1):9772. https://pubmed.ncbi.nlm.nih.gov/31278280/
[5] Covarrubias AJ, Perrone R, Grozio A, Verdin E. NAD+ metabolism and its roles in cellular processes during ageing. Nat Rev Mol Cell Biol. 2021;22(2):119-141. https://pubmed.ncbi.nlm.nih.gov/33353981/
[6] Brakedal B, Dölle C, Riemer F, et al. The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson's disease. Cell Metab. 2022;34(3):396-407.e6. https://pubmed.ncbi.nlm.nih.gov/35235774/
[7] Wang DD, Airhart SE, Zhou B, et al. Safety and Tolerability of Nicotinamide Riboside in Heart Failure With Reduced Ejection Fraction. JACC Basic Transl Sci. 2022;7(12):1183-1196. https://pubmed.ncbi.nlm.nih.gov/36644285/
[8] Dellinger RW, Santos SR, Morris M, et al. Repeat dose NRPT (nicotinamide riboside and pterostilbene) increases NAD+ levels in humans safely and sustainably: a randomized, double-blind, placebo-controlled study. NPJ Aging Mech Dis. 2017;3:17. https://pubmed.ncbi.nlm.nih.gov/29184669/
[9] Okabe K, Yaku K, Uchida Y, et al. Oral Administration of Nicotinamide Mononucleotide Is Safe and Efficiently Increases Blood Nicotinamide Adenine Dinucleotide Levels in Healthy Subjects. Front Nutr. 2022;9:868640. https://pubmed.ncbi.nlm.nih.gov/35479740/
[10] Igarashi M, Nakagawa-Nagahama Y, Miura M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. NPJ Aging. 2022;8(1):5. https://pubmed.ncbi.nlm.nih.gov/35927255/
[11] Lin JB, Kubota S, Ban N, et al. NAMPT-Mediated NAD+ Biosynthesis Is Essential for Vision In Mice. Cell Rep. 2016;17(1):69-85. https://pubmed.ncbi.nlm.nih.gov/27681422/
[12] Chellappa K, McReynolds MR, Lu W, et al. NAD precursors cycle between host tissues and the gut microbiome. Cell Metab. 2022;34(12):1947-1959.e5. https://pubmed.ncbi.nlm.nih.gov/36476934/
[13] Boo YC. Mechanistic Basis and Clinical Evidence for the Applications of Nicotinamide (Niacinamide) to Control Skin Aging and Pigmentation. Antioxidants (Basel). 2021;10(8):1315. https://pubmed.ncbi.nlm.nih.gov/34439563/
[14] Han S, Du Z, Liu K, Gong S. Nicotinamide riboside protects noise-induced hearing loss by recovering the hair cell ribbon synapses. Neurosci Lett. 2020;725:134910. https://pubmed.ncbi.nlm.nih.gov/32171805/
[15] Vinten KT, Trętowicz MM, Coskun E, et al. NAD+ precursor supplementation in human ageing: clinical evidence and challenges. Nat Metab. 2025. https://pubmed.ncbi.nlm.nih.gov/41083806/
[16] U.S. Food and Drug Administration. Dietary supplement regulatory status of NMN and the NAD+ precursor marketplace (FDA position that NMN is excluded from the dietary-supplement definition following authorization for investigation as a drug); product purity and labeling considerations for NAD+ precursors. FDA, 2022-2023. https://www.fda.gov/food/dietary-supplements
[17] Grant R, Berg J, Mestayer R, et al. A Pilot Study Investigating Changes in the Human Plasma and Urine NAD+ Metabolome During a 6 Hour Intravenous Infusion of NAD+. Front Aging Neurosci. 2019;11:257. https://pubmed.ncbi.nlm.nih.gov/31619986/
[18] U.S. Food and Drug Administration. Enforcement Report — Class I recall of a compounded NAD+ injection for elevated bacterial endotoxin (compounded sterile injectable, not FDA-approved). FDA Recalls, Market Withdrawals & Safety Alerts. https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts
[19] World Anti-Doping Agency. The Prohibited List (NAD+, NMN, nicotinamide riboside and nicotinamide are not prohibited). WADA. https://www.wada-ama.org/en/prohibited-list

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The NAD+ hype screenshotted and stapled to its source — the precursor trials that genuinely raised blood NAD+ stamped confirmed, the hard-outcome claims stamped preliminary, oral precursors kept apart from the compounded IV NAD+ behind a Class I recall, and the contested NMN status read as a dispute, not a ban; no clinic behind this corkboard and nothing here dosed, infused, prescribed, or sold.