Director's blog

Summary of recent NMN human clinical trials (2)

武本 重毅


This time, we would like to introduce a report from the University of Tokyo Hospital.

I was surprised to find that

taking NMN 250mg for just 12 weeks was effective.

Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men

npj Aging. 2022; 8:5


A research group led by

Assistant Professor Masaki Igarashi,

Dr. Yoshiko Nakagawa-Nagahama,

Dr. Masaomi Miura, and

Professor Toshimasa Yamauchi

of the Department of Diabetes and Metabolism, The University of Tokyo Hospital,

conducted a randomized, double-blind, parallel-group, placebo-controlled study

to investigate the effects of oral ingestion of a nicotinamide mononucleotide (NMN)

as a precursor of nicotinamide adenine dinucleotide (NAD+)

on muscle weakness and other aging phenomena of healthy elderly men.


They found that

oral administration of 250 mg NMN per day for 12 weeks in healthy elderly men

increased blood levels of NAD+ and related metabolites,

and improved motor functions such as walking speed and grip strength.

Furthermore, it was found that oral intake of NMN tended to improve hearing ability.

Prevention of sarcopenia is a major issue in Japan’s super-aging society.

From the results of this study,

oral intake of NMN is expected to have a preventive effect on sarcopenia,

and it is believed that it will contribute to the extension of healthy life expectancy in the future.


This study first examined the safety of administering NMN to elderly men,

and whether NMN intake increased NAD+ (nicotinamide adenine dinucleotide),

a coenzyme deeply involved in aging control,

in the same way as in experiments with mice.

As a result of having elderly men take NMN for 12 weeks,

there were no particular adverse events, and safety was confirmed.

In addition,

in the NMN intake group,

NAD+ in the blood increased more than twice as much as the placebo group (control group)

in 12 weeks.


NAD+ in the body decreases with age.

Aging and the development of age-related diseases

such as diabetes, cardiovascular disease, cancer, and dementia of the Alzheimer’s type

are closely related to decreased NAD+.

Once in the body, NMN is quickly converted to NAD+

and activates sirtuins, enzymes that control aging.

Sirtuins are also called longevity genes, and activation of these enzymes is said to delay aging.

Therefore, increasing NAD+ in the blood through NMN intake

is considered to hold the key to aging control.


Furthermore, the most noteworthy result of this research is

that the numerical values of “walking speed,” “grip strength,” and “30-second chair standing test,”

which are indicators of motor function,

significantly improved in the NMN intake group.

There was little change in these numbers in the placebo group.

“Walking speed” and “grip strength” are indicators used as diagnostic criteria for sarcopenia,

which requires nursing care as it progresses.

Ingestion of NMN improves “walking speed” and “grip strength” and may prevent sarcopenia.


Another point worth noting is

that the NMN intake group tended to improve their hearing ability.

Hearing loss affects communication with others,

greatly reduces the quality of life,

and increases the risk of developing dementia.

Although NMN has been reported to improve eye function in mouse studies,

hearing improvement has received little attention.


Therefore, chronic oral NMN supplementation can be an efficient NAD+ booster

for preventing aging-related muscle dysfunctions in humans.


武本 重毅