Podcast: More on Boosting NAD+
NutritionFacts.orgPublished on September 18, 2025
Summary authored by editor@wellifi.com
TLDR Summary
This article explores the potential benefits and limitations of Nicotinamide Mononucleotide (NMN) as a supplement for boosting NAD+ levels. While animal studies show promise, human trials have not demonstrated significant efficacy, and safety remains a concern.
Key Points
- NMN and NR are both precursors to NAD+, but NMN may be more stable in the bloodstream.
- Human studies on NMN show no significant effects on various health metrics.
- Safety evaluations for NMN in humans are lacking, raising concerns about nerve degeneration.
- Alternative NAD+ boosting supplements include niacin and tryptophan, but they come with their own risks.
Exploring NMN: A Potential Supplement for Health
Have you ever wondered if there are more natural ways to lower your high blood pressure, guard against Alzheimer's, lose weight, and feel better? Well, it turns out there is! Welcome to the Nutrition Facts Podcast. I’m your host, Dr. Michael Greger. In this article, we continue our series on ways to boost the production of the important metabolic enzyme NAD+ by reviewing a supplement called NMN (Nicotinamide Mononucleotide).
The Basics of NMN
Both NMN and its counterpart NR (Nicotinamide Riboside) have shown beneficial effects in rodent studies. However, neither has been tested head-to-head. Both precursors raise blood levels of NAD+ in humans, but NMN may have certain advantages. For instance, NMN appears to be more stable in the bloodstream compared to NR, as seen in mouse blood studies.
NMN vs. NR: The Controversy
One argument in favor of NMN is that it is a direct precursor of NAD+, while NR must first convert to NMN. However, NMN's phosphate charge can prevent it from passing through cell membranes, raising questions about its efficacy as a supplement. Recent studies suggest the existence of an NMN transporter in mouse intestines, but the evidence remains controversial.
Human Studies on NMN
Despite the promising animal studies, human research on NMN is limited. A small study involving healthy middle-aged men found no significant effects on various health metrics after single doses of NMN. A 12-week study of daily NMN supplementation similarly yielded no significant outcomes on lean mass, muscle mass, or blood parameters.
Effects on Aerobic Capacity
One study titled “Nicotinamide Mononucleotide Supplementation Enhances Aerobic Capacity in Amateur Runners” tested NMN on recreational runners. While some improvements in aerobic capacity were noted, there were no significant benefits for overall performance or other measures of cardiopulmonary function.
Safety and Efficacy Concerns
While NMN is touted as naturally occurring in fruits and vegetables, the concentrations found in these foods are much lower than typical supplement doses. Safety evaluations for NMN in humans are lacking, and there are concerns about potential nerve degeneration associated with NMN accumulation.
Alternative NAD+ Boosting Options
Other NAD+ boosting supplements include niacin and tryptophan. Niacin is more efficient than tryptophan for boosting NAD+, but tryptophan has been linked to serious side effects, including eosinophilia-myalgia syndrome (EMS). Directly taking NAD+ is impractical due to its instability and poor bioavailability.
Conclusion
In summary, while NMN shows promise in rodent studies for boosting NAD+ levels, its efficacy and safety in humans remain unproven. Both NR and NMN have not demonstrated significant benefits in human trials, and alternative NAD+ boosting options have their own risks. As always, it is essential to consult with a healthcare professional before considering any new supplement.
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