Disclaimer: This article is for informational purposes only and does not replace medical advice. Always consult a doctor before starting to use dietary supplements.
Last updated: August 2025
Author:
Daniel Lazarevic
Reviewed by:Simon Sinclair, PhD, Professor of Genetics
Long-term effects of NMN – What the research says so far (2025)
Summary in brief
- NMN raises NAD⁺ levels and may affect energy, cell function and ageing.
- Animal studies show improved metabolism, physical function and protection against age-related diseases.
- Human studies are promising but small and short-term.
- Safety: Doses up to 900 mg/day are tolerated in the short term; long-term safety has not been established.
- Knowledge gaps: long-term data, optimal dose, differences between groups.
What is NMN?
NMN (nicotinamide mononucleotide) is a precursor to NAD⁺, a coenzyme central to energy metabolism, DNA repair and cell health. NAD⁺ levels fall with age. Supplements such as NMN are being investigated for a potential role in healthy ageing.
NMN is a form of vitamin B3 and occurs naturally in small amounts in foods such as broccoli, avocado and green peas – but the amounts required for a measurable effect cannot in practice be obtained through diet, which is why it is sold as a dietary supplement. You will find our full range in our NMN & NAD+ collection.
NMN compared with NR (Nicotinamide Riboside)
NMN and NR are both NAD⁺ precursors from the same B3 family. NMN is one step closer to NAD⁺ in the body's conversion chain, while NR is a stable, well-established form that has also been shown to raise NAD⁺ levels effectively. Research on both is still ongoing, and the choice between them is currently more about price, availability and personal preference than a clear scientific winner.
Current research on long-term use of NMN
Summary of studies
| Study | Population | Dose | Duration | Results | Source |
|---|---|---|---|---|---|
| Mills et al. (2016) | Mice | 100–300 mg/kg | 12 months | Improved metabolism, reduced weight gain, no toxicity | PMID: 28703895 |
| Long et al. (2019) | Alzheimer's model (mice) | ≈300 mg/kg | 6 months | Improved mitochondrial function, protection against cognitive decline | PMID: 31415723 |
| Yoshino et al. (2021) | 25 women (prediabetes) | 250 mg/day | 10 v | Improved insulin signalling | PMID: 33509948 |
| Kim et al. (2021) | Amateur runners | 600 mg/day | 6 v | Increased aerobic capacity | PMID: 33782469 |
| Vrablik et al. (2022) | 80 adults | 300–900 mg/day | 60 d | ↑ NAD⁺ levels, ↑ endurance, good tolerance | PMID: 36243185 |
Findings from animal studies
- Reduced age-related weight gain and improved insulin sensitivity.
- Improved mitochondrial function and protection in neurodegenerative models.
Results from human studies
- 250 mg/day improved muscle insulin signalling in postmenopausal women.
- 600 mg/day increased aerobic capacity in runners.
- Up to 900 mg/day for 60 days increased NAD⁺ and endurance, with good tolerance.
Research gaps and limitations
- Long-term safety: Effects of use over several years are unknown.
- Optimal dose: Varies between studies; not established.
- Populations: Differences depending on sex, age and health status are insufficiently mapped.
- Limited evidence base: Few registered NMN studies on ClinicalTrials.gov relative to NR.
“Marketing in this area is several steps ahead of the scientific research, which underlines the need for extensive, long-term trials.” – Dr. Taylor C. Wallace
Safety profile and dosage
Reported side effects
- Humans, short term: generally well tolerated up to 900–1250 mg/day.
- Animals, high doses: risk of liver effects and kidney damage.
Recommendations
- Stay within 250–500 mg/day if at all, in consultation with a doctor.
- Over 900 mg/day only after medical assessment.
- Be particularly careful if you have underlying conditions or are on medication.
How NMN works in the body
NMN is converted into NAD⁺, which activates sirtuins and supports energy metabolism, DNA repair and inflammation control. Animal data show improved mitochondrial function and reduced oxidative stress.
Practical advice for consumers
- Choose quality: Third-party testing and a clearly stated purity.
- Certifications: e.g. U.S. Pharmacopeia/NSF where applicable.
- Lifestyle first: Diet, exercise, sleep. NMN is not a replacement.
- Medical advice: Consult healthcare professionals before starting/increasing.
Lifestyle as a complement to NMN
NMN works best as a complement to, not a replacement for, basic lifestyle factors. Longevity research points time and again to the same four cornerstones: a nutritious diet, regular physical activity, 7–9 hours of sleep, and stress management and social relationships. Anyone who wants to support their NAD⁺ system broadly should see NMN supplements as an addition to these habits, not a shortcut around them. Adaptogenic plant extracts, such as Tongkat Ali, are another example of supplements that several studies have linked to better stress management and hormonal balance – and that may be relevant to combine with an NAD⁺-focused routine.
Conclusion
NMN is promising for cell health and age-related processes. Long-term human data is lacking. Use with caution, choose high quality and involve healthcare professionals.
FAQ
Is NMN safe to take daily?
Short-term studies indicate good tolerance up to 900–1250 mg/day. Long-term safety in humans is unclear. Follow your doctor's advice.
How does NMN differ from NR?
Both are NAD⁺ precursors. Comparative long-term data and bioavailability between NMN and NR are limited.
What are the risks at high doses?
Animal data point to liver and kidney effects at very high doses. Stick to documented levels and consult a doctor.
Sources
- Mills KF et al. Cell Metab. 2016. PMID: 28703895
- Long AN et al. Front Aging Neurosci. 2019. PMID: 31415723
- Yoshino M et al. Science. 2021. PMID: 33509948
- Kim C et al. J Int Soc Sports Nutr. 2021. PMID: 33782469
- Vrablik M et al. Nutrients. 2022. PMID: 36243185
- ClinicalTrials.gov – search term “NMN”
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