A human clinical trial published in the journal Science showed that postmenopausal obese women with diabetes 

who took 250 mg of NMN daily for 10 weeks increased their muscle insulin sensitivity by about 25%, an improvement 

similar to that achieved by losing 10% of their weight or using the insulin sensitizer troglitazone for 12 weeks. In 

addition, supplementing NMN10 weeks can also increase the number of myoblasts in the skeletal muscle of the 

subjects and improve the regenerative capacity of skeletal muscle.

Type 2 diabetes is caused by insulin resistance. Therefore, increasing the body's sensitivity to insulin has become 

a natural treatment idea. In 2021, researchers at the University of Washington School of Medicine found that oral 

supplementation with NMN (niacinamide mononucleotide) can enhance insulin sensitivity, and the study was 

published in the top academic journal Science.

How can you test your sensitivity to insulin? The "gold standard" is the hyperinsulinemic-euglycemic clamp (HEC) 2. 

"High insulin" refers to high insulin levels in the body during the test, while "positive glucose clamp" refers to the 

concentration of glucose in the body as if the "clamp" is fixed at a normal level.

Insulin plays a role in lowering blood sugar in the body, and the higher the insulin sensitivity, the stronger the body's 

ability to lower blood sugar. In other words, at a given insulin level, subjects who can "withstand" a larger amount of 

external glucose input and maintain normal blood sugar have a higher insulin sensitivity, which is the core principle 

of the hyperinsulin-positive glucose clamp method.

In the actual test, the researchers first injected insulin to make the insulin in the blood of the subjects at a higher level; 

The goal is to suppress the subject's own insulin secretion and the liver's glucose output, so that both insulin and 

glucose levels in the blood are completely controlled by exogenous injections. Then, the researchers will continue to 

inject insulin and glucose, and constantly adjust the rate of glucose input to maintain the subject's blood sugar level. 

As mentioned above, once the blood sugar is stabilized, the rate of external glucose input (and the rate at which the 

body consumes glucose) can reflect the insulin sensitivity of the subject.

The participants in the clinical trial were 25 postmenopausal women who were overweight or obese and had symptoms 

of pre-diabetes. They were unknowingly divided into an experimental group (13 participants) and a placebo group 

(12 participants). After 10 weeks of 250mg/ day of oral NMN, the experimental group showed a 25% increase in muscle 

insulin sensitivity compared to the control group, which was reflected in the experimental data as a higher rate of glucose consumption.

Further, the researchers observed that supplementing with NMN enhanced insulin-related signaling pathways in the subjects' 

muscles, as evidenced by higher total AKT and mTOR phosphorylation levels in the experimental muscles.

In summary, the clinical trial found that 10 weeks of oral NMN of 250mg/ day enhanced insulin sensitivity, similar to the effect 

of 10% weight loss in obese people or 12 weeks of treatment with troglitazone (an insulin sensitizer). This finding may give 

NMN a place in the future treatment of type 2 diabetes.