Giving male mice a supplement called NMN for a year seems to help keep their muscle, fat, and liver genes from changing as they age — especially in muscle and fat, where most age-related gene shifts didn’t happen.

What we've found so far is that long-term NMN supplementation may help reduce age-related gene changes in certain tissues of male mice. The evidence we've reviewed leans toward this effect, particularly in muscle and fat. Our analysis of the available research shows that in one study, male mice given NMN for a year showed fewer age-related gene changes in muscle, fat, and liver tissues compared to those not receiving the supplement [1]. The effect was most noticeable in muscle and fat, where most of the typical shifts in gene activity linked to aging did not occur in the supplemented mice [1]. This suggests that NMN might help maintain more youthful gene patterns in these tissues over time. We only looked at one assertion from the research, and it supports this idea—no studies we reviewed contradicted it [1]. Still, this is based on limited evidence, and we cannot say how this might apply to other tissues, to female mice, or to humans. We also don’t yet know which specific genes are involved or how these changes might affect health or lifespan. Our current analysis shows a consistent direction in the data we’ve seen, but the picture is still incomplete. We’re continuing to review new studies as they become available. Practical takeaway: In male mice, taking NMN daily for a year may help keep gene activity in muscle and fat more stable with age—but we don’t yet know what this means for aging or health in people.