Cardiovascular and cerebrovascular diseases are most terrible killers endangering the health of Chinese residents, and hypertension is the most important risk factor. Hypertension related vascular function and structural damage are the common pathological basis and initiation of cardiovascular and cerebrovascular disease. Therefore, reducing blood pressure and delaying or reversing vascular injury is an effective way to treat hypertension and prevent cardiovascular disease. NAD+ (nicotinamide adenine dinucleotide) is a coenzyme of many kinds of dehydrogenases in the body, and is an essential molecule in the basic process of life support. The latest research found that with the growth of age, the level of NAD+ is decreasing, and increasing the content of NAD+ can prolong the life of multiple species including human. NMN (β - nicotinamide mononucleotide) is a natural NAD+ precursor in cells. Recent clinical trials found that NMN supplementation can effectively improve the level of NAD+ in cells, delay aging, improve the metabolic process of cells without adverse reactions. However, the effect of NMN supplementation on reducing blood pressure and protecting vascular endothelial function has not been reported. Therefore, this study aims to focus on hypertension, a major chronic disease, and to observe the effects of NMN supplementation on vascular function and blood pressure in patients with hypertension, so as to provide a new treatment strategy for hypertension and associated vascular injury.

Inclusion Criteria:

• Mild essential hypertensive patients (BP ranged from 130/80 to 159/99 mmHg).
• Ability to undergo Study procedures.
• Willingness/ability to provide informed consent.

Exclusion Criteria:

• Participants with secondary hypertension.
• Participants suffering from diabetes mellitus, coronary heart disease, peripheral vascular disease, acute or chronic liver disease, renal insufficiency, malignancies, infectious disease, or using non-steroidal anti-inflammatory drugs, steriods, vasoactive agents.
• Known allergies to niacin or nicotinamide.
• Receiving certain concurrent supplements.
• Women who are currently pregnant or who wish to become pregnant over the course of the study follow-up or who are at suckling period.
• Unwillingness/inability to provide informed consent.

Study biostatistician will be blinded to group (NMN vs. controls)