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NMN and NR are both vitamin B3 compounds that raise NAD+ levels in the blood. NR has more human trials, mostly in healthy or overweight adults over 6–12 weeks; NMN trials are fewer and mostly small. No published trial has compared them directly, and neither has been shown to slow aging in people. Trials used 250–1,000 mg a day of either one.
In This Article
What NMN and NR Are
NAD+ (nicotinamide adenine dinucleotide) is a molecule that cells use to make energy and repair DNA. Its levels fall with age in many tissues, which is why NAD+ “precursors” are sold for healthy aging. NR (nicotinamide riboside) and NMN (nicotinamide mononucleotide) are two such precursors; the body converts both into NAD+. Most of the excitement comes from studies in mice, not people.
What the Human Trials Show
NR (nicotinamide riboside)
- Raises NAD+ in a dose-dependent way: in an 8-week trial in overweight adults, 100, 300 and 1,000 mg a day raised whole-blood NAD+ by 22%, 51% and 142% within 2 weeks (Conze et al., 2019).
- Well tolerated in older adults: in a 6-week crossover trial in healthy middle-aged and older adults, NR raised NAD+ metabolism with no serious side effects; effects on blood pressure and arterial stiffness need further trials (Martens et al., 2018).
- Reaches muscle: in 12 older men, 1 g a day for 21 days raised NAD+ metabolites in muscle and lowered some inflammatory markers, without changing mitochondrial function (Elhassan et al., 2019).
- No metabolic benefit in obesity: in 40 obese men, 2,000 mg a day for 12 weeks was safe but did not improve insulin sensitivity or glucose metabolism (Dollerup et al., 2018).
NMN (nicotinamide mononucleotide)
- Insulin sensitivity: in a 10-week trial in postmenopausal women with prediabetes and overweight or obesity, 250 mg a day of NMN increased muscle insulin sensitivity compared with placebo (Yoshino et al., 2021).
- Older men: 250 mg a day for 6 or 12 weeks raised blood NAD+ and was well tolerated; gait speed and grip strength showed small changes that need confirming in larger studies, and body composition did not change (Igarashi et al., 2022).
- Doses up to 900 mg: in 80 healthy middle-aged adults, 300, 600 or 900 mg a day for 60 days raised blood NAD+ (most at 600–900 mg) and improved a 6-minute walking test compared with placebo; the trial was run by NMN manufacturers (Yi et al., 2023).
A 2025 meta-analysis of trials in adults over 60 found no effect of NMN on muscle mass, grip strength or walking speed; NR improved walking distance only in people with peripheral artery disease and gave worse scores on some physical tests in people with mild cognitive impairment. The authors concluded the evidence does not support either supplement for muscle health in older adults (Prokopidis et al., 2025).
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NMN vs NR at a Glance
| NR | NMN | |
|---|---|---|
| Raises blood NAD+ | Yes, dose-dependent | Yes |
| Human trials | More, including longer and higher-dose ones | Fewer, mostly small |
| Doses used in trials | 100–2,000 mg a day | 250–900 mg a day |
| Proven benefit on health outcomes | None confirmed | Early signals (insulin sensitivity, walking test) |
| Direct comparison | No published head-to-head trial | |
Which One Should You Choose?
If you want to try an NAD+ precursor, the honest answer is that the choice matters less than the expectation: both raise NAD+ in the blood, and neither has been shown to extend healthspan in people. NR has the larger and longer safety record. NMN has a couple of positive small trials on metabolic and physical measures. Choose one, not both: they lead to the same molecule.
- Dose: trials used 250–1,000 mg a day; there is no evidence that more is better.
- Timing: both are water-soluble, and the trials gave them once or twice a day; you do not need a fatty meal.
- Stacks: there is no good evidence that adding resveratrol helps; a 2012 trial found that resveratrol did not improve metabolic function in non-obese women with normal blood sugar (Yoshino et al., 2012).
Regulation and Quality
NR is sold under its own trade names and has “generally recognized as safe” status for use in foods. NMN had an uncertain status in the US until September 2025, when the FDA concluded that it is not excluded from the definition of a dietary supplement. Choose products with a clear dose per capsule and independent testing.
Side Effects and Safety
- Short-term trials (up to 12 weeks for NR at 2,000 mg a day and 60 days for NMN at 900 mg a day) found no serious side effects.
- Long-term safety is unknown, and there are no data in pregnancy or breastfeeding.
- Ask your doctor first if you have cancer or a history of cancer, or if you take prescription medicines: NAD+ affects cell growth and metabolism, and long-term effects have not been studied.
Frequently Asked Questions
Is NMN better than NR?
No trial has compared them directly. Both raise NAD+ in the blood; NR has more human data and NMN has a few positive small trials.
Can I take NMN and NR together?
There is no reason to: both are converted into the same molecule. Pick one and stay within trial doses.
Do NAD+ supplements slow aging?
That has not been shown in people. Most of the evidence for longer life comes from animal studies.
For other healthy-aging options and what the evidence says about them, see our longevity supplements guide.
Scientific References
- Conze D, et al. 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
- Martens CR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun. 2018. PMID 29599478
- Elhassan YS, et al. Nicotinamide riboside augments the aged human skeletal muscle NAD+ metabolome and induces transcriptomic and anti-inflammatory signatures. Cell Rep. 2019. PMID 31412242
- Dollerup OL, et al. 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
- Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021. PMID 33888596
- Igarashi M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood NAD+ levels and alters muscle function in healthy older men. NPJ Aging. 2022. PMID 35927255
- Yi L, et al. The efficacy and safety of beta-nicotinamide mononucleotide supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. GeroScience. 2023. PMID 36482258
