Human studies have shown that NMN supplementation can significantly increase blood NAD+ levels in overweight or obese adults. However, the physiological benefits of this increase produce complex results.

I. NMN reduces weight and lowers cholesterol and blood pressure

In 2023, Bhasin et al. of Harvard Medical School reported in February in the Journal of Clinical Endocrinology and Metabolism, demonstrating that NMN lowered total cholesterol, including "bad" LDL cholesterol, and lowered blood pressure. These findings support the metabolic stabilising effect of NMN.

Researchers, in order to investigate the effects of NMN on body weight, gave middle-aged and older overweight or obese adults 1,000 mg of NMN twice a day for 28 days. This resulted in a weight loss of more than six pounds compared to participants who did not receive NMN. This finding suggests that NMN supplementation promotes metabolic benefits, which was demonstrated by an important metabolic health indicator, namely body weight.

The researchers also assessed the effects of NMN on cardiovascular health by checking blood cholesterol levels. The results showed that NMN supplementation lowered total cholesterol and LDL cholesterol levels, which are known to be associated with heart-related problems. These findings support the idea that NMN can have a positive impact on the cardiovascular system by lowering cholesterol levels.

In addition, the study explored whether NMN improved heart function by measuring diastolic and systolic blood pressure. Interestingly, the study found that NMN specifically reduced diastolic blood pressure, a key factor in hypertension, while systolic blood pressure remained unchanged. These results suggest that NMN supplementation may be a potential strategy to alleviate hypertension in overweight and obese adults.

This study provides data and evidence that NMN can be effective in reducing weight in middle-aged and older adults who are overweight or obese. However, the relatively short-term nature of the study raises questions about the anti-obesity benefits that might be realised if more prolonged dose administration were to take place. It is reasonable to assume that a longer study duration may enhance the anti-obesity effects of NMN. In addition, a longer study duration may have contributed to further reductions in cholesterol and blood pressure levels.

II. NMN improves metabolic syndrome

As we all know, the most effective way to control obesity is to lose weight through exercise. Previously, some scholars also compared the effects of exercise and NMN for weight loss, and found that they are not equal, but NMN is better in improving metabolism and mitochondrial function. The reason is that after taking NMN can improve the level of NAD+ molecules in the body, enhance mitochondrial activity, reduce the metabolic rate of sugar, fat and protein, and reduce fat accumulation.

The rationale for this is that NMN causes a decrease in hepatic genes involved in fat synthesis, transport and uptake and an increase in hepatic genes involved in the oxidative breakdown of fatty acids. This finding suggests that short-term administration of NMN may be a therapeutic approach to treat metabolic disorders caused by maternal obesity and post-weaning nutritional processes that remain effective even in adulthood.

According to research experiments, NMN treatment improves reduced glucose tolerance induced by a high-fat diet in mice in just one week, which means that exercise improves body metabolism in all animal models, including ours, and this is achieved by increasing NAD+. Now NMN supplementation enhances NAD+ to do this. Increasing NAD+ levels with NMN supplementation has been shown to be effective for weight loss and metabolism enhancement as we age.

1.NAD + precursors improve obesity

Several studies have found that NAD+ levels in human adipose tissue, skeletal muscle, liver, and hypothalamus are decreased in obesity.Reduced NAD levels inhibit oxidative phosphorylation, the TCA cycle, and glycolytic reactions, which in turn reduce ATP production. In addition, reduced NAD levels affect PARPs and sirtuins and lead to inactivation of their downstream DNA repair, cellular stress response, and energy metabolism molecular pathways.

In addition to NAD+ deficiency, obesity inhibits the expression of the rate-limiting enzyme for NAD+ synthesis, NAMPT, due to the fact that nampt gene transcription and translation are affected by the level of inflammation, and obese individuals are almost always accompanied by chronic low-grade inflammation, with a high level of inflammatory factors (e.g., IL-1β, IL-6, and TNF-α) secreted in adipose tissue, liver, and skeletal muscle, etc., an inflammatory environment which inhibits the production of the enzyme NAMPT that unfavourable for NAD+ synthesis and recycling.

Altered NAD+ metabolism and insufficient NAD+ concentration in obese patients provide us with an idea to combat obesity with NAD+ precursors. This idea has been preliminarily verified in animals: NMN can maintain NAD+ levels in obese mice on a high-fat diet, preventing a series of unhealthy consequences triggered by the high-fat diet. In addition, NMN also has a preventive effect on "aging fat", which occurs along with weight gain in aging mice, and the situation of aging fat is improved in mice that have taken NMN for a long period of time.

2. NMN is more effective than prolonged exercise in terms of glucose tolerance and hepatic lipid metabolism in mice

Exercise is the first strategy that comes to mind when we talk about weight loss. Exercise can increase the rate of lipolysis, oxidative respiration, and mitochondrial biosynthesis, and FrontPharmacol's article confirms that NMN significantly improves glucose tolerance, hepatic lipid metabolism, and mitochondrial function in female obese mice, and that in some indexes, it even outperforms the effect of prolonged exercise (6 weeks), as demonstrated in an animal model:

1).Muscle NAD+ levels rebounded and NADH levels fell after exercise in female obese mice, indicating that exercise improved cellular oxidative respiratory capacity to some extent;

2).Obese mice that did not exercise but were supplemented with NMN also exhibited significantly higher muscle NAD+ levels, but at the same time NADH was maintained at a higher level, suggesting that NMN supplementation not only improves oxidative respiration, but also promotes rapid interconversion between NAD+ and NADH;

3).Exercise did not significantly improve liver NAD+ and NADH levels in obese female mice;

4).No exercise but NMN supplementation had a significant effect on liver energy metabolism in obese mice, with a substantial increase in the levels of NAD+ and NADH; and there was also a significant decrease in liver weight and hepatic triglycerides in the mice.

Unsurprisingly, the metabolic syndrome, marked by obesity and disorders of nutrient and energy metabolism, not only reduces NAD+ concentration but also inhibits sirtuins enzyme activity, but it inspires our intervention all the same. By supplementing NAD+ precursors, body weight, metabolism, fertility, and even the rate of aging was slowed down in various animal models of metabolic syndrome in the experiment.