NMN Benefits: What the Human Research Actually Says

The best-supported benefit of NMN in humans is that it raises blood NAD+ levels; studies suggest it may also support aspects of physical performance and metabolic health, but these findings come from small, short trials and research is ongoing. Bold claims about reversing ageing are not supported by human evidence. Here is what the published trials actually found.

New to the topic? Start with our guide to what NMN is and how it relates to NAD+.

Why researchers study NMN

NAD+ is a coenzyme involved in energy metabolism and in the activity of enzymes linked to cell maintenance. Levels appear to decline with age in several tissues. Because NMN is a direct precursor of NAD+, researchers want to know whether topping up NMN can support NAD+ and, in turn, the processes that depend on it.

Animal studies laid the groundwork. In a 2016 study, mice given NMN for 12 months showed less of the age-associated weight gain, decline in energy metabolism and loss of insulin sensitivity seen in control animals. Mouse findings are a reason to run human trials, not proof that the same happens in people.

Benefit 1: higher NAD+ levels (strongest evidence)

This is the most consistent finding across human trials.

• Yi et al., 2023 (GeroScience): 80 healthy adults aged 40 to 65 took 300, 600 or 900 mg of NMN or a placebo for 60 days. Blood NAD+ rose in all NMN groups, with the largest increases at 600 mg and 900 mg.
• Igarashi et al., 2022 (npj Aging): healthy men aged 65 and over took 250 mg a day for 12 weeks; NAD+ and related metabolites in blood rose compared with placebo.
• Okabe et al., 2022 (Frontiers in Nutrition): 250 mg a day for 12 weeks in healthy adults efficiently increased blood NAD+.

What this does not tell us is exactly how blood NAD+ relates to levels inside muscle, brain or other tissues. That is an active research question.

Benefit 2: physical performance and muscle function (emerging)

Walking endurance

In the 2023 Yi trial, the 600 mg and 900 mg groups walked further in a six-minute walking test than the placebo group. The study also reported a blood-based biological age estimate, but results like this need confirming in larger, longer trials.

Gait speed and grip strength in older men

Igarashi and colleagues reported improvements in some measures of muscle function, such as gait speed and grip performance, in older men taking 250 mg a day, while other measures did not change. The authors described the findings as preliminary.

Aerobic capacity in runners

A 2021 six-week trial in 48 amateur runners found that combining NMN with exercise training improved some measures of aerobic capacity, such as oxygen use at the ventilatory threshold, compared with training alone. Doses of 600 mg and 1,200 mg appeared to have larger effects than 300 mg.

Benefit 3: metabolic markers (early research)

A 2021 study published in Science gave 250 mg of NMN a day for 10 weeks to 25 postmenopausal women with overweight or obesity and prediabetes. Muscle insulin sensitivity improved in the NMN group compared with placebo, while body weight, blood pressure and blood lipids did not change. It was a small, tightly controlled study, and results in one group of people cannot simply be generalised to everyone.

What NMN has not been shown to do

• Extend human lifespan: no human evidence exists.
• Reverse ageing: biological-age measures in trials have produced mixed results.
• Treat or prevent disease: NMN is sold as a food supplement and is not a medicine.
• Replace lifestyle: exercise, sleep and diet also affect NAD+ metabolism.

If you want to follow a routine like the ones used in these studies, taking NMN every day for several weeks, a liquid NMN you can take in seconds makes consistency easier.

A note on dose: the studies above used NMN capsules or powder. Our liquid liposomal NMN drops use a 15 mg daily dose; as our product page explains, our liposomal 15 mg delivers more NMN to your cells than a 600 mg dose of NMN capsules. Read why our drops use 15 mg.

How to read NMN research yourself

• Check who was studied. Results in older men or prediabetic women may not apply to younger, healthy adults.
• Look at size and duration. Most NMN trials have had fewer than 100 people and lasted under three months.
• Separate biomarkers from outcomes. Higher NAD+ is a biomarker; feeling or functioning better is an outcome.
• Look for placebo control. Randomised, double-blind trials give the most reliable answers.

Making NMN part of a routine

If you decide to try NMN, the trials above used 250 mg to 900 mg a day, usually in the morning, and took several weeks to show changes in NAD+. See how much NMN to take and when and our overview of NMN safety and side effects. Our liposomal NMN drops are a liquid option if you prefer not to swallow capsules.

The bottom line

Human studies consistently suggest that NMN raises blood NAD+ and is well tolerated. Early trials point to possible support for walking endurance, muscle function and metabolic markers in certain groups, but they are small and short. Treat NMN as a promising, still-developing area of nutrition research rather than a proven anti-ageing solution.

Frequently asked questions

What is the main benefit of NMN?

The most consistent finding in human trials is an increase in blood NAD+ levels.

Does NMN give you energy?

NAD+ is involved in energy metabolism, but trials have not consistently measured feelings of energy. Some studies report improvements in physical performance measures.

Is NMN proven to slow ageing?

No. Animal studies are promising, but there is no human evidence that NMN slows or reverses ageing.

How long do NMN studies last?

Most human trials have run for 6 to 12 weeks.

Can NMN replace exercise?

No. In the runner study, benefits were seen when NMN was combined with training, not instead of it.

This article is for general information only and is not medical advice. Food supplements are not intended to diagnose, treat, cure or prevent any disease and should not replace a varied, balanced diet and healthy lifestyle. Speak to your doctor or pharmacist before taking NMN, especially if you are pregnant, breastfeeding, taking medication or managing a health condition.

References

1. Mills KF et al. (2016). Long-term administration of nicotinamide mononucleotide mitigates age-associated physiological decline in mice. Cell Metabolism. PubMed 28068222
2. Yi L et al. (2023). 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. PubMed 36482258
3. Igarashi M et al. (2022). Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. npj Aging. PubMed 35927255
4. Okabe K et al. (2022). Oral administration of nicotinamide mononucleotide is safe and efficiently increases blood nicotinamide adenine dinucleotide levels in healthy subjects. Frontiers in Nutrition. PubMed 35479740
5. Liao B et al. (2021). Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study. Journal of the International Society of Sports Nutrition. PubMed 34238308
6. Yoshino M et al. (2021). Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. PubMed 33888596
7. Irie J et al. (2020). Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men. Endocrine Journal. PubMed 31685720
8. Covarrubias AJ et al. (2021). NAD⁺ metabolism and its roles in cellular processes during ageing. Nature Reviews Molecular Cell Biology. PubMed 33353981