NMN and NAD+ are best known for helping to slow the aging process. NMN (nicotinamide mononucleotide) is the precursor to NAD+ (nicotinamide adenine dinucleotide), a coenzyme found in all living cells. Increased levels of NAD+ are thought to enhance survival. By the time we reach middle age, most people have about half the amounts they had when they were younger.
NMN supplements have been taken off the market in the US by the FDA recently.
Alternative supplementation may be available through NAD+ injections. Please consult with your healthcare provider with any questions or concerns.
Preliminary clinical studies have shown possible adverse effects on organs and organ systems, but so far, no results have been conclusive.
Human clinical studies are still lacking regarding safety and efficacy.
By taking NMN orally, it is believed that it can be an effective anti-aging compound, thereby ultimately improving NAD+ levels. Currently, there are no known side effects when taking NMN supplements. However, it is essential to let your physician know that you are taking NMN since it was recently taken off the market in the US by the FDA.
In fact, the FDA has recently recommended disallowing NMN as a dietary supplement, and it may not be marketed or sold in the US at present. However, this may be temporary, and there are still companies that legally sell NMN produced prior to this decision.
Why tell my doctor I'm taking NMN?
The FDA in the US has halted the sale of NMN as a dietary supplement — though it may be available elsewhere. If you have access to NMN or desire an alternative, it is a good idea to discuss its use with your healthcare provider.
The FDA surprisingly decided to prohibit the sale of NMN in November 2022. The supplement was banned without notice regarding its safety and efficacy. It was widely believed that the FDA may have favored drugmakers as opposed to the producers of dietary supplements. Nonetheless, NMN requires more research to test potential safety concerns.
Since NMN is no longer available in the US, some healthcare providers are advocating an alternative — NAD+ injections. However, there is no clear evidence supporting NAD+ injections as an anti-aging strategy, despite some promising yet still speculative results reported in a couple of studies. Another unknown of NAD+ injection is that the metabolism of intravenously infused NAD/NADH is currently unclear.
Result of higher NAD+ levels by taking NMN?
Some experts believe that taking NMN may increase NAD+ levels in the blood but not inside the tissues, where it is needed. In addition, while some studies report positive effects of NMN both in animal and human studies, it is still unclear whether these potential benefits may outweigh the potential risks.
Studies on NMN and NAD+ administration
What are the health claims surrounding NMN and NAD-boosting products? Some preliminary evidence suggests NAD-boosting supplements may improve metabolic function, which some experts argue may increase longevity. Other claims include the following:
- Increases NAD+ biosynthesis
- May prevent age-associated weight gain
- May improve insulin sensitivity
- May enhance energy metabolism and physical activity
- May improve muscle endurance and strength
- Potentially can support cardiovascular health
- May improve neuronal function in the brain
- May improve eye function
However, the evidence around these benefits is still thin and inconsistent. Our best, most reliable data to date on the longevity effects of NAD-boosting products such as NMN comes from a series of studies by the Interventions Testing Program at the National Institute on Aging. These studies reported that supplementation with nicotinamide riboside (NR), another NAD-boosting supplement did not extend the lifespan in treated mice relative to controls.
Contradictory is also the data around the potential benefit of NMN administration for improving triglycerides and cholesterol levels. While some preclinical studies in mice show benefits, others show potential harm.
Uncertain benefits and safety concerns
In addition to the uncertain benefits of supplementing with NAD-boosting supplements, there are some safety concerns.
There have been reports of adverse effects on several human organs and organ systems, including the liver, kidney, and pancreas. For instance, users have noted bouts of nausea, stomach upset, and headaches.
Furthermore, preclinical studies in mice indicate that NMN use may cause a possible increase in cancer risk in mice and structural changes in the brain along with behavior deficits. However, it is unclear whether those effects would translate to humans or how.
The main issue regarding NMN use has been that the safety cannot be accurately assessed because of dosing. Therefore, recommendations regarding safe levels for long-term administration have been elusive.
Rigorous scientific preclinical and clinical studies are lacking. Much of the criticism regarding the lack of clinical research is that manufacturers have found that low profit margins make it challenging to fund clinical research.
One reason the FDA halted the sale and marketing of NMN is due to the lack of regulation. Currently, there is no distinction between the marketing and sale of NMN products. In addition, without clinical research to prove safety, there are many unknowns.
As much as scientists know about the benefits of taking NMN, much more research is necessary because it's still in its infancy. Once more data is analyzed, researchers will have a better indication of how effective NMN products may be for increasing longevity.
Someday, NAD-boosting supplements may prove useful for treating very specific diseases, but when it comes to general use for longevity, the evidence supporting their anti-aging benefits is too unconvincing to overcome the potential risks of cancer acceleration and the potential suppression of endogenous NAD synthesis.
Please be aware that from the fall of 2022 NMN is under an investigation as a potential new drug by the FDA. That puts the legality of the product as a dietary supplement in question. It’s a complicated situation that’s not yet solved. However, it is important to note that since we are not a manufacturer or retailer, we do not take any responsibility for the availability of the product as a dietary supplement after having lost its dietary ingredient status.
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