Evidence explainerNMN (nicotinamide mononucleotide)
Does NMN Work? It Raises NAD, but Pooled Trials Find Little Else So Far
NMN reliably raised blood NAD in a 60-day trial. Whether that turns into better blood sugar, muscle or aging is a different question, and the pooled human data are mostly null.
Key takeaways
- In 80 healthy middle-aged adults, 300, 600 or 900 mg/day of NMN for 60 days raised blood NAD versus placebo [1].
- Across 8 trials (342 adults), NMN did not significantly change fasting glucose, insulin, HbA1c or blood lipids [2].
- One 9-trial analysis found faster gait speed, but a review limited to adults with a mean age over 60 found no gait-speed effect [3][6].
- Across 15 trials at 250 to 2,000 mg/day for up to 24 weeks, NMN did not increase adverse events [4].
- Human trials have measured NAD, metabolic markers and physical function, not aging or lifespan [1][4].
The evidence, graded
Pulled from our monograph evidence tables. Grades follow our evidence-grading policy.
- Grade CImprovedBlood NAD and six-minute walking distanceBlood 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 showed no significant benefit on fasting glucose, fasting insulin, HbA1c, HOMA-IR or the lipid profile.
- Grade CImprovedGait speed and liver enzymes in middle-aged and older adultsNMN improved gait speed (SMD 0.34) and lowered ALT (SMD -0.29).
NAD: the part that works
In a 60-day randomized trial of 80 healthy middle-aged adults, blood NAD rose in every NMN group (300, 600 and 900 mg/day) at days 30 and 60 compared with placebo, and was highest at 600 and 900 mg [1].
The same trial reported longer six-minute walking distance in all NMN groups, with no difference in HOMA-IR versus placebo [1]. Its "blood biological age" result came from an algorithm-based calculator (Aging.Ai 3.0), a surrogate measure [1].
Blood sugar and cholesterol: no clear benefit
A 2024 meta-analysis of 8 randomized trials (342 adults, mostly without diabetes) using 250 to 2,000 mg/day found no significant benefit on fasting glucose, fasting insulin, HbA1c, HOMA-IR or lipids [2].
A 2026 meta-analysis of 15 trials also found no effect on weight, glucose, HbA1c or lipids, with a slight drop in diastolic blood pressure [4]. One 10-week trial in postmenopausal women with prediabetes did find better muscle insulin sensitivity [5].
Muscle and walking: mixed
A 2025 meta-analysis of 9 trials (412 middle-aged and older adults) found NMN improved gait speed (SMD 0.34) and lowered the liver enzyme ALT [3]. Its authors go further and call NMN an anti-aging drug candidate, which the modest pooled effects do not show [3].
A separate 2025 meta-analysis in adults with a mean age of 60.9 to 83 found NMN had no significant effect on muscle mass index, grip strength, gait speed or chair-stand time [6].
Safety and status
Across 15 trials using 250 to 2,000 mg/day for 14 days to 24 weeks, NMN did not increase adverse events or liver enzymes; longer-term safety is unknown [4]. FDA concluded on September 29, 2025 that NMN is not excluded from supplements [7]; see is NMN legal in the US.
Quick answers
Does NMN slow aging?
That has not been shown in people. The animal studies reported healthspan and lifespan effects, while human trials measured blood NAD, metabolic markers and physical function [1][4].
Does NMN help with weight loss?
A 2026 meta-analysis of 15 trials found no significant effect on body weight or BMI [4].
Does NMN raise blood pressure?
No rise was found: systolic pressure did not change and diastolic pressure fell slightly across trials [4].
Keep reading
Full monographs
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References
- [1]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.
- [2]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.
- [3]Effects of Nicotinamide Mononucleotide Supplementation on Muscle and Liver Functions Among the Middle-aged and Elderly: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Curr Pharm Biotechnol, 2025.
- [4]Safety and Metabolism-Related Outcomes of Oral Nicotinamide Mononucleotide Supplementation in Adults: A Systematic Review and Meta-Analysis. Nutrients, 2026.
- [5]Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science, 2021.
- [6]The Effect of Nicotinamide Mononucleotide and Riboside on Skeletal Muscle Mass and Function: A Systematic Review and Meta-Analysis. J Cachexia Sarcopenia Muscle, 2025.
- [7]Letter on NDIN 1259 (beta-nicotinamide mononucleotide), December 2, 2025. U.S. Food and Drug Administration, 2025.