The formation of gray hair is mainly due to the decline or loss of function of melanocytes—cells responsible for producing melanin, the pigment that gives hair its black color. As people age, the number and activity of melanocytes gradually decrease, leading to hair graying. In recent years, studies have found that NMN (nicotinamide mononucleotide) can improve gray hair symptoms through multiple pathways.
First, NMN enhances the activity of melanocytes. Supplementing with NMN increases the intracellular content of NAD+ (nicotinamide adenine dinucleotide), which in turn activates the metabolic process of melanocytes and promotes the synthesis and secretion of melanin.
Second, NMN exerts antioxidant and anti-inflammatory effects. Oxidative stress and inflammatory responses are key factors that damage melanocytes and accelerate their aging. As a potent antioxidant and anti-inflammatory agent, NMN reduces the damage caused by these adverse factors to melanocytes and protects their normal function.
Additionally, NMN improves the hair follicle microenvironment—a critical site for hair growth, where a stable microenvironment is essential for healthy hair. By regulating the metabolism and signal transmission of hair follicle cells, NMN promotes the proliferation and differentiation of these cells, thereby facilitating melanin production and hair growth.
Preliminary studies have confirmed NMN’s potential in reversing gray hair. For example, one study found that after supplementing mice with NMN, the number of melanocytes in their hair follicles increased significantly, and melanin production also improved markedly. Another study showed that NMN enhanced the skin tone of aged mice, making their skin smoother and more elastic. These findings suggest that NMN may improve melanocyte function by increasing NAD+ levels in the body, thereby potentially turning gray hair black.
References
[1] Pucciarelli, S., Moreschini, B., et al. Spermidine and Spermine Are Enriched in Whole Blood of Nona/Centenarians. Rejuvenation Research, 15, 590–595 (2012).[2] Schwarz, C., Horn, N., et al. Spermidine Intake is Associated with Cortical Thickness and Hippocampal Volume in Older Adults. NeuroImage, 221: 117132.