# NAD+ References: The Studies Behind This Research Digest

> The full reference list behind this NAD+ digest — peer-reviewed trials and reviews on the coenzyme, NMN, NR, nicotinamide, and infused NAD+, with DOIs and PubMed links.

Every quantitative claim on this site traces to one of the studies below.

## About these sources

Every quantitative claim in this NAD+ digest — each dose, percentage, duration and pharmacokinetic figure — maps to a numbered source below. The list draws on randomized human trials, mechanistic studies and recent reviews, weighted toward peer-reviewed primary literature and current syntheses such as the 2023 and 2025 reviews of NAD+ precursor supplementation. Where a study used a brand name in its own title (for example a trial of a named NR ingredient), the citation reproduces that title verbatim as a matter of accurate referencing; it is not an endorsement of any product. You can read more [about this research digest](/about), and the [frequently asked questions about NAD+](/faq) answer common queries directly.

## 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] Berven H, Kverneng S, Sheard E, et al. NR-SAFE: a randomized, double-blind safety trial of high dose nicotinamide riboside in Parkinson's disease. Nat Commun. 2023;14(1):7793. https://pubmed.ncbi.nlm.nih.gov/38016950/
[7] Freeberg KA, Udani R, Bostwick AD, et al. Dietary Supplementation With NAD+-Boosting Compounds in Humans: Current Knowledge and Future Directions. J Gerontol A Biol Sci Med Sci. 2023;78(12):2435-2448. https://pubmed.ncbi.nlm.nih.gov/37068054/
[8] Chen AC, Martin AJ, Choy B, et al. A Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer Chemoprevention. N Engl J Med. 2015;373(17):1618-1626. https://pubmed.ncbi.nlm.nih.gov/26488693/
[9] Kim LJ, Chalmers TJ, Smith GC, et al. Host-microbiome interactions in nicotinamide mononucleotide (NMN) deamidation. FEBS Lett. 2023;597(17):2196-2220. https://pubmed.ncbi.nlm.nih.gov/37463842/
[10] Kar A, Mehrotra S, Chatterjee S. CD38: T Cell Immuno-Metabolic Modulator. Cells. 2020;9(7):1716. https://pubmed.ncbi.nlm.nih.gov/32709019/
[11] Groth B, Venkatakrishnan P, Lin SJ. NAD+ Metabolism, Metabolic Stress, and Infection. Front Mol Biosci. 2021;8:686412. https://pubmed.ncbi.nlm.nih.gov/34095234/
[12] Aleo MF, Giudici ML, Sestini S, Danesi P, Pompucci G, Preti A. Metabolic fate of extracellular NAD in human skin fibroblasts. J Cell Biochem. 2001;80(3):360-366. https://pubmed.ncbi.nlm.nih.gov/11135366/
[13] 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/
[14] Christen S, et al. The differential impact of three different NAD+ boosters on circulatory NAD and microbial metabolism in humans. Nat Metab. 2026. https://pubmed.ncbi.nlm.nih.gov/41540253/

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A dusk-drawn atlas of the NAD+ literature — the coenzyme charted apart from the NMN and NR precursors that rebuild it, the oral trials kept off the rapidly-cleared IV route, and the contested NMN status marked at the frontier; no clinic surveys behind this map and nothing here is dosed, compounded, prescribed, or sold.