NAD Safe

RESEARCH DIGEST / THE RECEIPTS

NAD+ References: Every Claim, Stapled to Its Study

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.

What the trials measuredThe safety picture

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.

  1. Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224-1229. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  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. ↗
  15. Vinten KT, Trętowicz MM, Coskun E, et al. NAD+ precursor supplementation in human ageing: clinical evidence and challenges. Nat Metab. 2025. ↗
  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. ↗
  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. ↗
  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. ↗
  19. World Anti-Doping Agency. The Prohibited List (NAD+, NMN, nicotinamide riboside and nicotinamide are not prohibited). WADA. ↗