Evidence explainerNicotinamide riboside (NR)NMN (nicotinamide mononucleotide)

NMN vs NR: No Head-to-Head Trial, and Similar Results So Far

NMN and nicotinamide riboside are both sold as NAD+ boosters. Both raise blood NAD in trials, neither has improved blood sugar, and no trial has compared them directly.

By Kymata Health editorial teamPublished October 9, 2026Last reviewed October 9, 2026

Medical review pending. Written by our editorial team from the studies cited below; a credentialed clinician has not reviewed it yet. Educational only, not medical advice.

Key takeaways

  • Both are NAD+ precursors, and no randomized trial in our sources compares them head to head [1].
  • NR at 100, 300 and 1,000 mg/day raised whole-blood NAD+ by 22%, 51% and 142% over 8 weeks [2].
  • NMN at 300, 600 and 900 mg/day raised blood NAD versus placebo over 60 days [3].
  • A 12-week NR trial and a meta-analysis of 8 NMN trials both found no improvement in insulin sensitivity or blood sugar markers [4][5].
  • A 2025 meta-analysis concluded the evidence does not support either for preserving muscle in adults over 60 [1].

Safety at a glance

From our Nicotinamide riboside (NR) monograph. Published interactions and cautions only, each with its source.

Who should be careful

  • Long-term use. The trials we reviewed ran for 6 months at most, and safety was reported for up to 12 weeks, so longer-term safety is not established.[5][3]
  • Older adults seeking muscle benefits. A 2025 meta-analysis concluded that current evidence does not support NR or NMN for preserving muscle mass and function in adults over 60.[7]
  • Before you start. Talk to your pharmacist or clinician before adding this supplement, especially if you take prescription medicines, are pregnant or breastfeeding, or have a chronic health condition.[2]

Full Nicotinamide riboside (NR) safety section

The evidence, graded

Pulled from our monograph evidence tables. Grades follow our evidence-grading policy.

  • Grade CImprovedBlood NAD+ levelsNicotinamide riboside (NR) · RCT · n=20 · 2024 · PMID 37994989Blood NAD+ rose 2.6-fold with NR, with no between-group difference in adverse events. Cognition scores (MoCA) did not change.
  • Grade CNo effectInsulin sensitivity and glucose metabolismNicotinamide riboside (NR) · RCT · n=40 · 2018 · PMID 29992272NR did not improve insulin sensitivity, glucose production, glucose disposal, energy expenditure, fat oxidation or body composition. No serious adverse events were observed.
  • Grade CImprovedBlood NAD and six-minute walking distanceNMN (nicotinamide mononucleotide) · RCT · n=80 · 2023 · PMID 36482258Blood NAD rose in all NMN groups versus placebo. Six-minute walking distance increased more with all doses than placebo, most with 600 and 900 mg. HOMA-IR did not differ from placebo, and NMN was well tolerated.
  • Grade CNo effectFasting glucose, insulin, HbA1c and lipidsNMN (nicotinamide mononucleotide) · Meta-analysis · n=342 · 2024 · PMID 39531138NMN showed no significant benefit on fasting glucose, fasting insulin, HbA1c, HOMA-IR or the lipid profile.

What they are

NMN and NR are both precursors that the body can use to make NAD+ [1]. They have been studied mostly in separate trials, and the 2025 meta-analysis that covered both pooled them against placebo, not against each other [1].

Raising NAD: both do

In an 8-week trial, NR at 100, 300 and 1,000 mg/day raised whole-blood NAD+ by 22%, 51% and 142% within 2 weeks, and the rise held for the rest of the study [2].

In a 60-day trial of 80 adults, NMN at 300, 600 and 900 mg/day raised blood NAD versus placebo, most at 600 and 900 mg [3]. The two trials used different populations and NAD measures, so the size of the rises cannot be compared directly [2][3].

Health outcomes: similar, mostly null

NR at 2,000 mg/day for 12 weeks did not improve insulin sensitivity, glucose metabolism or body composition in 40 men with insulin resistance [4]. For NMN, a meta-analysis of 8 trials (342 adults) found no significant effect on glucose, insulin, HbA1c or lipids [5].

In adults with a mean age of 60.9 to 83, NMN did not improve muscle mass, grip strength or gait speed, and NR results were mixed [1]. The authors concluded the evidence does not support either for preserving muscle mass and function [1].

US regulatory status differs

FDA had no questions about a GRAS notice for nicotinamide riboside chloride as a vitamin B3 source in foods such as vitamin waters and nutrition bars; the notice closed on August 3, 2016 [6].

For NMN, FDA held from 2022 that it was excluded from supplements, then concluded on September 29, 2025 that it is not excluded [7]. More in is NMN legal in the US.

Quick answers

Is NMN or NR better absorbed?

No trial in our sources measured both in the same people [1]. Each raised blood NAD in its own trials [2][3].

Does NR cause flushing like niacin?

In the 8-week trial there were no reports of flushing at 100 to 1,000 mg/day, and adverse events did not differ from placebo [2].

Is NMN the same as NAD?

No. NMN is a precursor the body uses to make NAD+ [1].

Keep reading

Full monographs

Related articles

Browse the full Supplement & Nutrient Encyclopedia or all supplement articles.

References

  1. [1]The Effect of Nicotinamide Mononucleotide and Riboside on Skeletal Muscle Mass and Function: A Systematic Review and Meta-Analysis. J Cachexia Sarcopenia Muscle, 2025. PMID 40275690
  2. [2]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. PMID 31278280
  3. [3]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. PMID 36482258
  4. [4]A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects. Am J Clin Nutr, 2018. PMID 29992272
  5. [5]Effects of Nicotinamide Mononucleotide on Glucose and Lipid Metabolism in Adults: A Systematic Review and Meta-analysis of Randomised Controlled Trials. Curr Diab Rep, 2024. PMID 39531138
  6. [6]GRN No. 635: Nicotinamide riboside chloride (FDA has no questions, closed Aug 3, 2016). U.S. Food and Drug Administration, 2016.
  7. [7]Letter on NDIN 1259 (beta-nicotinamide mononucleotide), December 2, 2025. U.S. Food and Drug Administration, 2025.

Nicotinamide riboside (NR) and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. This page has no product or affiliate links.