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NAD Precursors Special-Populations Summary: Prescribing and Class Review

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At a glance

  • Class / Oral NAD+ precursors: nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR)
  • Regulatory status / Dietary supplements, not FDA-approved drugs [4]
  • Studied groups / Generally healthy midlife and older adults, adults with overweight or obesity, postmenopausal women with prediabetes, people with Parkinson's disease [3][1][2]
  • Not studied in the reviewed trials / Pregnancy, breastfeeding, children, cancer, kidney or liver disease [3]
  • Doses tested / NMN 100 mg as a single dose [5] and 250 to 1,250 mg/day repeated [6][7]; NR 100 mg/day [8] to 3,000 mg/day [2]. Studied doses, not recommended doses.
  • Injectable NAD+ / Compounded product, not FDA-approved [9]

Who was studied?

Most trials lasted 12 weeks or less and enrolled 12 to 140 participants, so they cannot establish longer-term safety [3]. The groups enrolled were generally healthy midlife and older adults, adults with overweight or obesity, and people with Parkinson's disease [3]. Postmenopausal women with prediabetes were the population in a 10-week NMN trial [1], and newly diagnosed, untreated Parkinson's patients were the population in a 30-day NR trial [10].

Prediabetes and older adults

  • A 10-week trial in postmenopausal women with prediabetes who were overweight or obese found insulin-stimulated glucose disposal rose after NMN and did not change after placebo [1].
  • In a 21-day crossover study of 12 men aged 70 to 80, NR 1 g/day did not raise muscle NAD+ (210 vs 197 pmol/mg, p=0.22) and mitochondrial respiration, grip strength, insulin sensitivity and muscle blood flow were unchanged [11].
  • A 2025 review of randomized trials in older adults with mean ages from 60.9 to 83 years found NMN had no significant effect on skeletal muscle index, handgrip strength, gait speed or the 5-times chair stand test [12].

Pregnancy, breastfeeding and children

Safety during pregnancy or breastfeeding is unknown, and the reviewed trials did not include children [3].

Cancer, kidney and liver disease## Cancer, kidney and liver disease

People with cancer, kidney disease or liver disease were not included in the trials reviewed, and safety in these groups is unknown [3]. Cancer risk with chronic NAD+ boosting has been raised as a theoretical concern, with no human data identified [3].

Drug interactions and regulatory status## Drug interactions and regulatory status

A 2023 review identified no human drug-interaction studies of NMN or NR, including CYP, transporter and pharmacodynamic studies [3]. There is no label interaction list, because neither compound is an approved drug [4].

NMN and NR are sold in the US as oral dietary supplements. Neither is FDA-approved for any use, and no NAD+ precursor product is approved by FDA to treat aging or any disease [4]. Injectable or IV NAD+ is a compounded product, not an FDA-approved drug [9].

Frequently asked questions

Can NMN or NR be taken during pregnancy or breastfeeding?
Unknown. The reviewed trials did not include pregnant or breastfeeding women [3].
Do NMN or NR interact with prescription drugs?
A 2023 review identified no human drug-interaction studies of NMN or NR, and there is no label interaction list because neither is an approved drug [3][4].
Are NMN or NR FDA-approved?
No. Both are sold as oral dietary supplements and neither is an FDA-approved drug, and no NAD+ precursor is approved to treat aging or any disease [4]. Injectable or IV NAD+ is compounded, not approved [9].

References

  1. Yoshino M, Yoshino J, Kayser BD, Patti GJ, Franczyk MP, Mills KF, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224-1229. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women
  2. Berven H, Kverneng S, Sheard E, Søgnen M, Af Geijerstam SA, Haugarvoll K, 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. NR-SAFE: a randomized, double-blind safety trial of high dose nicotinamide riboside in Parkinson's disease
  3. Freeberg KA, Udovich CC, Martens CR, Seals DR, Craighead DH. 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. Dietary Supplementation With NAD+-Boosting Compounds in Humans: Current Knowledge and Future Directions
  4. Official web page. Official web page
  5. Irie J, Inagaki E, Fujita M, Nakaya H, Mitsuishi M, Yamaguchi S, 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. Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men
  6. Okabe K, Yaku K, Uchida Y, Fukamizu Y, Sato T, Sakurai T, 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. Oral Administration of Nicotinamide Mononucleotide Is Safe and Efficiently Increases Blood Nicotinamide Adenine Dinucleotide Levels in Healthy Subjects
  7. Fukamizu Y, Uchida Y, Shigekawa A, Sato T, Kosaka H, Sakurai T. Safety evaluation of β-nicotinamide mononucleotide oral administration in healthy adult men and women. Sci Rep. 2022;12(1):14442. Safety evaluation of β-nicotinamide mononucleotide oral administration in healthy adult men and women
  8. 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. 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
  9. Bulk Drug Substances Used in Compounding of the FD&C Act | FDA. Bulk Drug Substances Used in Compounding of the FD&C Act | FDA
  10. Brakedal B, Dölle C, Riemer F, Ma Y, Nido GS, Skeie GO, 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. The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson's disease
  11. Elhassan YS, Kluckova K, Fletcher RS, Schmidt MS, Garten A, Doig CL, et al. Nicotinamide Riboside Augments the Aged Human Skeletal Muscle NAD+ Metabolome and Induces Transcriptomic and Anti-inflammatory Signatures. Cell Rep. 2019;28(7):1717-1728.e6. Nicotinamide Riboside Augments the Aged Human Skeletal Muscle NAD+ Metabolome and Induces Transcriptomic and Anti-inflammatory Signatures
  12. Prokopidis K, Moriarty F, Bahat G, McLean J, Church DD, Patel HP. The Effect of Nicotinamide Mononucleotide and Riboside on Skeletal Muscle Mass and Function: A Systematic Review and Meta-Analysis. J Cachexia Sarcopenia Muscle. 2025;16(3):e13799. The Effect of Nicotinamide Mononucleotide and Riboside on Skeletal Muscle Mass and Function: A Systematic Review and Meta-Analysis
  13. Shi H, Enriquez A, Rapadas M, Martin EMMA, Wang R, Moreau J, et al. NAD Deficiency, Congenital Malformations, and Niacin Supplementation. N Engl J Med. 2017;377(6):544-552. NAD Deficiency, Congenital Malformations, and Niacin Supplementation
  14. Chowdhry S, Zanca C, Rajkumar U, Koga T, Diao Y, Raviram R, et al. NAD metabolic dependency in cancer is shaped by gene amplification and enhancer remodelling. Nature. 2019;569(7757):570-575. NAD metabolic dependency in cancer is shaped by gene amplification and enhancer remodelling
Evidence overview for classes nad precursors: NAD Precursors Special-Populations Summary: Prescribing and Class Review