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MD NAD+

NAD+ under examination

MD NAD+ · The medical file

NAD+ reading list

Human experiments, animal findings and reviews sit together here. Their differences are often as useful as their conclusions.

Read the human resultsReturn to the file opening

Human trials

The NMN muscle study gives me the clearest place to start with function. Its unchanged HbA1c deserves the same attention as the improvement in muscle insulin sensitivity. The multicenter walking study asks a different performance question.

For a clear blood-biomarker finding, the eight-week NR study is useful beside the six-week crossover trial. The 2025 review places such experiments within the broader human evidence.

Mechanisms and other settings

The NAD+ metabolism review supplies the cellular background. The CD38 experiment in mice examines consumption of the supply, while the proposed NMN transporter in mice addresses uptake and remains debated.

The plasma and urine infusion pilot, melanoma-cell and mouse work and topical nicotinamide review repay separate attention. Their routes, tissues and questions differ substantially.

  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. Trammell SA, Schmidt MS, Weidemann BJ, et al. Nicotinamide riboside is uniquely and orally bioavailable in mice and humans. Nat Commun. 2016;7:12948. ↗
  7. Martens CR, Denman BA, Mazzo MR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun. 2018;9(1):1286. ↗
  8. Irie J, Inagaki E, Fujita M, et al. Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men. Endocr J. 2020;67(2):153-160. ↗
  9. Grozio A, Mills KF, Yoshino J, et al. Slc12a8 is a nicotinamide mononucleotide transporter. Nat Metab. 2019;1(1):47-57. ↗
  10. 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. ↗
  11. 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. ↗
  12. 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. ↗
  13. Audrito V, Managò A, La Vecchia S, et al. Nicotinamide Phosphoribosyltransferase (NAMPT) as a Therapeutic Target in BRAF-Mutated Metastatic Melanoma. J Natl Cancer Inst. 2018;110(3):djx198. ↗
  14. Williams PA, Harder JM, Foxworth NE, et al. Vitamin B3 modulates mitochondrial vulnerability and prevents glaucoma in aged mice. Science. 2017;355(6326):756-760. ↗
  15. Vinten KT, Trętowicz MM, Coskun E, et al. NAD+ precursor supplementation in human ageing: clinical evidence and challenges. Nat Metab. 2025. ↗
  16. 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. ↗