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October 19, 2026

NMN Supplements: What the Human Studies Show, and What They Don't

By The MDR Team · Editorial standards

A small dish of white powder on an oak table beside broccoli, a bowl of edamame and half an avocado

NMN (nicotinamide mononucleotide) is a building block your cells use to make NAD+, a coenzyme whose measured levels are lower in older adults. In human trials, NMN taken by mouth at 250 mg a day or more consistently raises NAD+ in the blood and has been well tolerated for up to 24 weeks. What has not been shown is that this produces clear benefits for muscle, metabolism or daily function in healthy people: the results are small and mixed, and a 2026 trial in adults 65 and older found no improvement in physical performance. In September 2025 the FDA reversed an earlier position and concluded NMN is not excluded from the definition of a dietary supplement.

NMN gets a lot of attention as a healthy-aging supplement, and much of what is written about it runs ahead of the research. We sell a product that contains it, so here is what the human studies found.

NMN and NAD+ in one paragraph

NAD+ is a coenzyme present in every cell. It carries electrons in the reactions mitochondria use to turn food into energy, and it is used by enzymes involved in cell maintenance and repair. NMN sits one step before NAD+ in the body's production line. We explained NAD+ in more detail in What NAD+ actually is.

Researchers are interested because NAD+ levels measured in human tissue are lower in older people. In skin samples from 49 people, NAD+ was lower at older ages in both men and women (Massudi and colleagues, 2012), and blood plasma studies across ages 20 to 87 show a similar decline (Clement and colleagues, 2019).

The mouse research

In 2016, a study in mice given NMN in their drinking water for a year reported that it softened several age-related changes in metabolism and physical activity (Mills and colleagues, 2016). Results like that drew interest in human trials. They are also the reason so much NMN marketing sounds bigger than the human evidence: mice are not people, and what happens in a mouse over a year often does not repeat in a human trial.

What the human trials found

It raises NAD+ in the blood. This part is consistent across trials. In a 12-week trial of 30 healthy adults, NMN at 250 mg a day raised whole-blood NAD+ with no abnormal test results or obvious side effects (Okabe and colleagues, 2022). A 60-day trial of 80 middle-aged adults tested 300, 600 and 900 mg a day and found blood NAD+ rose in every NMN group, highest at 600 and 900 mg (Yi and colleagues, 2023).

Effects on the body are smaller and less consistent.

  • In 25 postmenopausal women who were overweight and had prediabetes, 250 mg a day for 10 weeks improved how well their muscles responded to insulin, measured with a clamp test, the most direct method available. It did not change body composition, blood pressure, blood lipids or liver insulin response (Yoshino and colleagues, 2021). It was a small study of one specific group.
  • In healthy older men, 250 mg a day for 6 or 12 weeks raised blood NAD+, with "nominally significant" improvements in walking speed and left-hand grip that the authors said need confirming in larger studies. Body composition did not change (Igarashi and colleagues, 2022).
  • In a 12-week trial of 108 older Japanese adults, split between NMN at 250 mg a day and placebo, taken in the morning or the afternoon, the afternoon NMN group showed the largest improvement in a five-times sit-to-stand test and in drowsiness. But every group, including placebo, improved on the sit-to-stand test, and afternoon placebo also improved drowsiness, which makes the result harder to read (Kim and colleagues, 2022).
  • The middle-aged trial above also reported longer six-minute walking distances on NMN (Yi and colleagues, 2023). Its lead author and two co-authors work for chemical and pharmaceutical companies, as the paper discloses.

The larger, more recent picture is less encouraging. A 2025 meta-analysis pooled the randomized trials in older adults and found that NMN had no significant effect on muscle mass, grip strength, walking speed or chair-stand performance (Prokopidis and colleagues, 2025). And in September 2026, a 24-week randomized trial in adults 65 and older, using a high dose of 1,250 mg a day, found that NMN "robustly" raised NAD+ and related compounds, but produced no statistically significant improvement in its main outcome (hearing) or in physical performance (Igarashi and colleagues, 2026).

Safety so far

The safety record in short and medium-term trials is reassuring. A 4-week trial of 1,250 mg a day in 31 healthy adults found no changes beyond normal variation in blood, urine or body measurements (Fukamizu and colleagues, 2022). A 2026 meta-analysis of 15 trials of NMN or related preparations, at 250 to 2,000 mg a day for up to 24 weeks, found no statistically significant increase in adverse events or liver enzymes in the 10 trials with safety data. It also found no broad metabolic benefit (Yang and colleagues, 2026). The 2026 high-dose trial still advised careful safety monitoring, and none of these trials ran for years.

One more thing worth knowing: much of this research was funded by, or done with, NMN makers. The 2026 trial was funded by the company that supplied its NMN, and several of the Japanese trials included employees of the NMN supplier. That does not make the results wrong, but it is part of the picture.

The FDA question

You may have read that NMN was "banned". In 2022 the FDA took the position that NMN could not be sold as a dietary supplement, because it had been studied as a possible drug. In September 2025, responding to a citizen petition from the Natural Products Association and the Alliance for Natural Health, the FDA reversed that view and concluded NMN is not excluded from the definition of a dietary supplement, since it was marketed as one before it was authorized for investigation as a new drug (FDA docket FDA-2023-P-0872).

That answers a legal question about NMN as an ingredient. It is not FDA approval of any product, and it says nothing about whether NMN works.

What we don't know yet

  • Whether higher blood NAD+ matters. Blood levels rise reliably. Whether muscle, brain and other tissues change in a way that affects health is not established in people.
  • Long-term safety. The longest trials we found ran 24 weeks.
  • The right amount. Studies range from 250 to 2,000 mg a day, and no dose has been shown to produce a reliable, meaningful benefit in healthy adults.
  • Who might benefit. Some researchers think people with lower starting NAD+ or early metabolic changes respond more. That is a hypothesis, not a finding.

Common questions

Does NMN raise NAD+?

Yes. This is the most consistent finding in the human trials, at the doses studied, from 250 mg a day upward.

Is 250 mg a day enough?

It is the amount used in several of the trials and it raised blood NAD+ in them. Higher doses raised NAD+ further in one trial. No dose has been shown to deliver a reliable, meaningful benefit in healthy adults.

Is NMN legal in supplements?

As an ingredient, yes. In September 2025 the FDA concluded that NMN is not excluded from the definition of a dietary supplement. That is not an approval of any particular product.

Will NMN make me stronger or give me more energy?

The trials have not shown that reliably. The pooled analysis in older adults found no significant effect on muscle mass or strength, and the 2026 high-dose trial found no statistically significant improvement in physical performance.

Where PowerFactors fits

MDR PowerFactors contains 250 mg of NMN per scoop, the amount used in several of the trials above, alongside 5 grams of creatine monohydrate, 100 mg of magnesium from magnesium bisglycinate and 100 mg of collagen peptides. Its label lists healthy aging among its benefits†. For NMN specifically, what the research supports is that it raises NAD+ in the blood; we don't claim the NMN in it will make you stronger or younger, because the research doesn't show that. No trial has tested PowerFactors itself. If you already take another NMN or NAD+ product, count it before adding this one, and see Creatine and NMN together for who the combination makes sense for.

Last updated October 19, 2026.

Sources

  • Okabe K, Yaku K, Uchida Y, et al. Oral administration of nicotinamide mononucleotide is safe and efficiently increases blood nicotinamide adenine dinucleotide levels in healthy subjects. Front Nutr. 2022;9:868640. PubMed 35479740
  • Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224-1229. PubMed 33888596
  • Igarashi M, Nakagawa-Nagahama Y, Miura M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. NPJ Aging. 2022;8(1):5. PubMed 35927255
  • Kim M, Seol J, Sato T, et al. Effect of 12-week intake of nicotinamide mononucleotide on sleep quality, fatigue, and physical performance in older Japanese adults: a randomized, double-blind placebo-controlled study. Nutrients. 2022;14(4):755. PubMed 35215405
  • Yi L, Maier AB, Tao R, et al. 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;45(1):29-43. PubMed 36482258
  • Prokopidis K, Moriarty F, Bahat G, et al. The effect of nicotinamide mononucleotide and riboside on skeletal muscle mass and function: a systematic review and meta-analysis. J Cachexia Sarcopenia Muscle. 2025;16(3):e13799. PubMed 40275690
  • Igarashi M, Naruse K, Takaoka Y, et al. Sustained NAD+ augmentation by high-dose nicotinamide mononucleotide supplementation in older adults: a 24-week randomized, double-blind, placebo-controlled trial. npj Aging. 2026. doi:10.1038/s41514-026-00482-7
  • Fukamizu Y, Uchida Y, Shigekawa A, et al. Safety evaluation of β-nicotinamide mononucleotide oral administration in healthy adult men and women. Sci Rep. 2022;12(1):14442. PubMed 36002548
  • Yang W, et al. Safety and metabolism-related outcomes of oral nicotinamide mononucleotide supplementation in adults: a systematic review and meta-analysis. Nutrients. 2026. PubMed 42514320
  • Massudi H, Grant R, Braidy N, et al. Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLoS One. 2012;7(7):e42357. PubMed 22848760
  • Clement J, Wong M, Poljak A, Sachdev P, Braidy N. The plasma NAD+ metabolome is dysregulated in "normal" aging. Rejuvenation Res. 2019;22(2):121-130. PubMed 30124109
  • Mills KF, Yoshida S, Stein LR, et al. Long-term administration of nicotinamide mononucleotide mitigates age-associated physiological decline in mice. Cell Metab. 2016;24(6):795-806. PubMed 28068222
  • U.S. Food and Drug Administration. Response to citizen petition on the regulatory status of β-nicotinamide mononucleotide (NMN), Docket FDA-2023-P-0872, September 2025. regulations.gov

†These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.