Taking 1000 mg of NMN every day for a month doesn’t help older adults with obesity get stronger in chest or leg presses, and might actually make their thigh muscles smaller compared to taking a fake pill.

What we've found so far is that taking 1000 mg of NMN daily for 4 weeks does not improve strength or muscle mass in older adults with obesity. In fact, the evidence we've reviewed leans toward a lack of benefit and even suggests possible negative effects on muscle size. Our analysis of the available research shows that in one assessment, 1000 mg of NMN taken daily for a month did not increase strength in chest or leg press exercises compared to a placebo [1]. This means participants did not get stronger despite taking the supplement. More notably, the same analysis found that those taking NMN may have experienced a reduction in thigh muscle size over the four-week period [1]. This suggests that, rather than supporting muscle maintenance or growth, NMN at this dose and duration might be linked to muscle loss in this specific group. The evidence we've reviewed comes from a single assertion, which aggregates findings across 45.0 supporting inputs and no refuting ones [1]. While the number of supporting inputs is high, we emphasize that this reflects consistency in one study’s outcome, not the breadth of independent research. At this point, we have not reviewed any studies that show benefits for strength or muscle mass with this NMN regimen in older adults with obesity. We recognize that this is a narrow view based on limited data. Our current analysis cannot determine long-term effects, impacts on other aspects of health, or how results might differ with longer use or different populations. We also cannot say whether changes in muscle size translate to functional differences in daily life. Practical takeaway: Based on what we've reviewed so far, taking 1000 mg of NMN daily for four weeks is unlikely to make older adults with obesity stronger or increase muscle mass—and it might be linked to losing muscle in the thighs.