インビボ研究1.NMNはミトコンドリアを保護し、また活性酸素とエネルギーを産出させる全面的にNMNの抗老化作用を知るために、科学者たちはサイトメガロウイルス(CMV)の中の活性酸素種（ROS）の産出とミトコンドリアの表現型との影響を調査しました。研究実験から高齢者の脳微小血管内細胞（BMEC）のミトコンドリアの酸化ストレスが軽減されたことが分かりました。2. 異なる細胞内のコンパートメントで、NMNは酵素を通してNADへ組織や細胞内のコンパートメントによって発現特異性が異なり、Nmnat1 は核に、Nmnat2 は細胞質とゴルジに、Nmnat3 はミトコンドリアと細胞質に局在します。3. NMNはNADを増加させることで、細胞機能を活性させるNMNを培養基に1時間を入れると、HeLa細胞とU937細胞のNAD量が増加しました。実験からヌクレオチドが細胞膜に浸透しやすいことが分かりました。NMNはPARP-1による過活性化を受けている細胞のNADとATPの機能低下を抑制することで、細胞の老化を防ぎます。[3]インビボ研究1. 細胞量の増加　NMNは細胞にエネルギーを供給することができます。ミトコンドリアはATPを産生して、細胞代謝とエネルギー産生で中心的な役割を果たしています。ミトコンドリアによるATPの産生と膜電位はニコチンアミドアデニンジヌクレオチド (NAD)に欠かせません。2. 肥満の抑制　肥満は脂肪組織の機能障害とインスリンの抵抗性と関連しています。NMNを摂取することで、インスリンの分泌が改善され、アディポネクチンが増加され、遊離脂肪酸が減少します。NMNが含まれる飲用水をマウスに飲ませることで、加齢に伴う体重増加を抑えます。加齢に伴い、臓器のNAD +とNAMPTが低下しますが、NMNは加齢による2型糖尿病を改善する効果が期待できます。3. 学習効率と記憶力の向上アルツハイマー病は、アミロイドβペプチド（Aβ）の沈着が要因となります。NMNはNAD +とATPを回復させることで、アミロイドβペプチドの海馬切片における ROSの蓄積を減少させました。本研究では、ADモデルマウスの認知機能が回復されたことが分かりました。NMNは神経細胞を賦活させる作用があり、またエネルギー代謝を改善し、ROSの蓄積を減少させます。4. 網膜の保護　視細胞が細胞死することにより、失明を引き起こし、Namptの欠損で網膜変性を引き起こします。Namptは合成系の鍵酵素としてNAD+量を調節します。5. 血流の促進と心臓の健康研究実験でNMNは局所虚血を予防する可能性が分かりました。通常では体の虚血プレコンディショニング（IPC）により虚血を防ぎます。IPCはSIRT1を刺激して、Sirt1はNAD＋依存性蛋白脱アセチル化酵素として血液を全身に送ることをサポートします。NMNはIPCと同じくSIRT1を刺激して、Sirt1を活性化することにより、心臓を保護し、虚血および再灌流を防ぎます。参考文献[1] S. Tarantini, et al. Redox Biology 24 (2019) 101192[2] F. Berger, C. Lau, M. Dahlmann, M. Ziegler, J. Biol. Chem. 280, 36334–36341 (2005).[3] L. Formentini,et al. Biochemical Pharmacology 77 (2009) 1612–1620[4] Stein, L. R., & Imai, S. (2012). The dynamic regulation of NAD metabolism in mitochondria. Trends in Endocrinology & Metabolism, 23(9), 420–428.[5] NAMPT-mediated NAD+ biosynthesis in adipocytes regulates adipose tissue function and multi-organ insulin sensitivity in mice. Cell Rep. 2016 August 16; 16(7): 1851–1860. doi:10.1016/j.celrep.2016.07.027.[6] Mills et al., Long-Term Administration of Nicotinamide Mononucleotide Mitigates Age-Associated Physiological Decline in Mice. 2016, Cell Metabolism 24, 795–806[7] Xiaonan Wang, et al. Nicotinamide mononucleotide protects against β-amyloid oligomer-induced cognitive impairment and neuronal death. Brain Research, Volume 1643, 15 July 2016, Pages 1-9[8] Jonathan B. Lin, et al. NAMPT-Mediated NAD+ Biosynthesis Is Essential for Vision In Mice. Volume 17, Issue 1, 27 September 2016, Pages 69-85[9] T Yamamoto, et al. Nicotinamide mononucleotide, an intermediate of NAD+ synthesis, protects the heart from ischemia and reperfusion. PLoS One. 2014; 9(6): e98972. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4048236/[10] Yellon D M, et al. Myocardial Reperfusion Injury. N Engl J Med. 2007 Sep 13; 357(11): 1121-35. https://www.ncbi.nlm.nih.gov/pubmed/17855673/[11] Yoshino et al. Cell Metab. 2011 October 5; 14(4): 528–536.doi: 10.1016/j.cmet.2011.08.014

Is the Enzyme eNampt the Future of Health and Longevity?A recent study out of Washington University School of Medicine in St. Louis has uncovered a compelling mechanism that could delay the inevitable and deleterious effects of aging. Previous research has determined that a decline in NAD (nicotinamide adenine dinucleotide) is a major contributor to accelerated aging and chronic disease development. As NAD can reduce the effects of cellular aging, thereby reducing the risk of chronic disease and increasing lifespan, maintaining elevated NAD levels has become a goal of every longevity researcher, biohacker, and anti-aging enthusiast.While there are a couple of well-established ways to increase lifespan through elevated NAD levels in yeast and animal studies, the research team on this study has discovered a new method, using eNAMPT. In this article, we’ll discuss the initial findings, as well as what eNAMPT is and what you need to know about this anti-aging enzyme.NAD+ and NMN: A ReviewIt’s well known that NAD is necessary to fuel every cell in our body; however, levels of NAD decline with age. Also referred to as NAD+ when it’s in its oxidized form, this coenzyme is one we literally cannot live without. Other than fueling cellular metabolism, another crucial action of NAD+ is its ability to activate sirtuins, which are a family of proteins that slow down the aging process — so much so, that they are nicknamed the “longevity genes.” However, you can’t take NAD+ as a supplement, as it would break down in the digestive system before your cells were able to use it effectively. Therefore, its precursors are often used to boost NAD+ levels. The two leading NAD+ precursors are NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside), both of which have been shown to increase NAD+ levels in cells and tissues.What is eNAMPT?Another lesser-known mechanism that boosts NAD+ levels is eNAMPT (extracellular nicotinamide phosphoribosyltransferase), another enzyme that is plentiful in youth but declines throughout the aging process. Researchers at the Washington University School of Medicine found that eNAMPT increases NAD+ levels primarily via its actions on the hypothalamus, which is the body’s control system for many crucial processes, including aging, thirst, hormonal balance, and the circadian rhythm. After being released from adipose tissue, eNAMPT travels to the brain and other tissues, where it internalizes into cells and produces NMN, which can then be converted into NAD+. Note that eNAMPT is one version of NAMPT; the other form is iNAMPT, indicating it is intracellular, while eNAMPT is extracellular. Both forms can synthesize NMN and are found in various tissues, including the skeletal muscle, brain, kidney, liver, and adipose tissue.Being extracellular, eNAMPT is carried by extracellular vesicles, or EVs, which are membrane-coated nanoparticles that function to deliver signals and molecules throughout the body. EVs are found circulating in the blood, which is what the researchers in this study used to increase eNAMPT in older mice.The eNAMPT StudyThe study, which was published in June 2019 in Cell Metabolism, aimed to determine if supplementing older mice with EVs containing eNAMPT was able to effectively boost NAD+ levels and improve markers of health and aging. Shin-ichiro Imai, MD, PhD, the research team isolated eNAMPT-containing EVs from the blood of young mice and supplemented them to aging mice. In an additional experiment, the researchers genetically engineered some of the mice to continue producing the higher, youthful levels of NAMPT in their adipose tissue as they aged.Compared to the control mice, the aging mice who received eNAMPT and the genetically engineered mice had overwhelmingly positive results, including improvements in:・Lifespan, which was extended by 16%・NAD+ production in the hypothalamus, hippocampus, pancreas, and retina・Endurance, measured through wheel-running activities・Sleep quality・Vision, through better functioning of photoreceptors in the eyes・Cognitive functioning, through increased NAD+ in the hippocampusInterestingly, there was a difference amongst sexes: Female mice with higher eNAMPT experienced longer lifespans and delayed aging symptoms for longer than male mice. Overall, however, the eNAMPT-supplemented mice were more youthful, energetic, and overall healthier than the control mice. These results are encouraging, as declines in energy, vision, and cognition are increasingly common age-related symptoms. Restoring these dysfunctions through the upregulation of eNAMPT could result in a healthier aging process.Longevity and eNAMPT Both forms of NAMPT are necessary components of the NAD salvage pathway, an internal recycling program that produces NAD+ from unused forms of niacinamide (also known as nicotinamide or NAM), including NMN and NR. After the body uses a molecule of NAD+, the leftover component is NAM. The NAD salvage pathway reuses it to create more NAD+ and is dependent on the activity of NAMPT. Thus, NAMPT is thought to be the enzyme responsible for controlling NAD+ levels in the body. Maintaining eNAMPT expression is linked to increased longevity and improved health outcomes. Because the hypothalamus is partially controlled by eNAMPT, a decline in eNAMPT levels may lead to hypothalamic dysfunction, which accelerates the aging process.As eNAMPT levels decrease, NAD+ would also diminish, leading to the underactivation of sirtuins, the longevity-regulating proteins.How to Upregulate eNAMPTSimilar to NAD+, there are no supplements of eNAMPT. However, there are a few ways to activate and upregulate the production of both forms of NAMPT. Although NMN does not convert into eNAMPT, NMN does directly enter cells and convert into NAD+. Through the NAD salvage pathway, any unused components of the NAD+ molecule could be recycled, thus continuing the feedback loop and providing additional fuel to maintain the production of NAD+.In some research, resveratrol and anthocyanidins have been shown to increase NAMPT levels, both of which are found in red grape skins. Anthocyanidins are polyphenols that function as antioxidants and are found in plants with red, blue, or purple pigments.In addition to supplements, some lifestyle interventions that can increase eNAMPT. Fasting or caloric restriction can upregulate eNAMPT, as well as sirtuin function and mitochondrial efficiency. Exercise has also been found to increase eNAMPT expression in the skeletal muscle. Key TakeawayA recent study discovered that the enzyme eNAMPT could effectively increase NAD+ levels in mice; NAD+ contributes to health and longevity when its levels are maintained throughout the aging process. In the study, aging mice who received blood with eNAMPT from young mice saw significant improvements in lifespan, cognition, endurance, vision, and sleep quality.Although no eNAMPT supplement exists, fasting, exercise, and resveratrol supplementation may boost levels naturally.

Nicotinamide mononucleotide (NMN) has been a front-running supplement in the anti-aging world due to its ability to convert to nicotinamide adenine dinucleotide (NAD+), a key component that activates a group of enzymes called sirtuins. Dubbed the “longevity genes,” sirtuins can help reverse DNA damage and reduce inflammation, both of which are major contributing factors to overall health degradation due to NAD+ depletion as we age. Another set of enzymes that require NAD+ to be activated are DNA-repairing genes called poly (ADP-ribose) polymerases (PARPs). Without adequate NAD+ levels, genes like sirtuins and PARPs can’t efficiently express themselves. This leads down a rough road that most people accept as the imminent phenomena of “getting older.”But what if getting older didn’t need to be so rough? It seems plausible that we can slow the aging clock if we simply boost our NAD+ levels by taking its precursor, NMN. However, a question is being raised by the longevity community as to whether NMN supplementation may work best when combined with methylation support.Let’s take a closer look at methylation, ways to support this vital biological process of the body, and maximize your NMN supplementation.What is Methylation?Methylation is a fundamental biochemical process in which CH3 (one carbon atom and three hydrogen atoms) is transferred from one molecule to another. This process is responsible for many of our body’s most important functions, such as:・Forming neurotransmitter・Producing free radical scavenging antioxidants・Clearing histamine・Cell division・Cellular energy production・Metabolism・DNA expression (epigenetics)We have a “methyl pool,” a storage center of sorts, containing CH3 methyl groups that we draw upon whenever transfers need to be made for these biochemical processes. If we have enough methyl groups stored in the pool, methylating typically isn’t a problem. However, there are reasons why methylating may pose a challenge for some people or change throughout one’s lifespan. Before exploring NMN supplementation and methylation, here are some common causes of decreased methylation.1. MTHFR VariantsMethylenetetrahydrofolate reductase (MTHFR) is a gene with common mutations that can cause high levels of homocysteine in the blood and low folate levels. Two main MTHFR variants — heterozygous and homozygous — are found worldwide spanning many ethnicities, although some variants seem to affect certain people more than others. Up to 40% of the population may have one or both genetic mutations. However, having an MTHFR mutation does not mean you will display symptoms of a disease or require treatment. Oftentimes, supplementing with methylated B vitamins or other methyl donors, such as TMG, is all that is necessary to support methylation.2. Aging and Epigenetics Methylation of DNA plays a crucial role in epigenetics — the expression of DNA. Methylation does not change the DNA sequencing itself, but rather it switches on and off different sequences of your genetic material when needed. Our methylation ability and subsequent DNA expression declines with age. Though we have a lot to learn about genetics and aging, changes in DNA expression may be linked to disease-related biomarkers, which may contribute to age-related diseases like cancer, osteoarthritis, and neurodegenerative conditions, suggests a study in Rejuvenation Research.NMN Supplementation and Methylation SupportThe ultimate goal of supplementing with NMN is to facilitate the conversion of NAD+ in our cells, thereby activating sirtuin genes and promoting longevity. This action is a part of the salvage pathway that involves the creation of nicotinamide (NAM). When the NAM compound is formed, it also needs to be expelled as a part of this natural pathway. To do this, NAM is methylated into N-methylnicotinamide, which is a metabolite found in our urine. When taken as a supplement, NMN may require the use of methyl groups to create and excrete N-methylnicotinamide. Currently, there is no evidence suggesting NMN’s natural methylation of NAM depletes our methyl pool. Even so, safeguarding against depletion and supporting methylation may be a proactive step to augmenting your NMN intake.How do top anti-aging experts suggest supporting this valuable methyl pool? By adding additional methyl donors to it. At the top of the list — trimethylglycine (TMG). Using TMG to Replenish the Methyl PoolTMG, an amino acid known as betaine, has three methyl groups attached to each molecule of glycine and operates along a pathway similar to B12, a crucial methyl donor. Methyl donors can replenish the methyl groups to support healthy methylation. After experimenting with methyl B-12 and methylfolate for methyl donation, anti-aging guru David Sinclair, Ph.D., switched to TMG as a singular methyl donor — purely as a preventative measure to protect against potential methylation depletion by way of NMN supplementation. “As a precaution, I take trimethylglycine so that I continue to give my body a source of methyl groups,” says Sinclair in an interview with Joseph Mercola, DO. “I don’t see any downside. It’s not an expensive molecule. The upside is that I’m preventing my body from being drained of methyl groups.”If you're currently taking NMN or thinking about starting, consider pairing it with TMG as an added support for methylation. Other methyl donors that may be useful include methylated B6, B12, and folate. Side Effect and ContraindicationsTMG is generally well-tolerated, but side effects such as mild digestive upset or headaches may occur in some people. Primary contraindications are for pregnant or breast-feeding individuals. Talk with your doctor if you have questions or concerns regarding the use of TMG as a part of your supplement protocol. The Bottom LineUltimately, supporting your body’s ability to maintain an adequate methyl pool by supplementing with TMG is worth considering as a precautionary measure. Taking the best NMN supplements along with a methyl donor such as TMG offers the most protection by aiding numerous body processes that require methylation — especially activation of longevity-promoting and reparative genes like sirtuins and PARPs. 

There is an irreversible and unavoidable aspect of reproductive aging that begins when a female reaches her late 30s. As women are now waiting longer to start families, this biological race against time is one of the main contributors to the increasing rates of infertility worldwide.Although we can't stop the years from going by, new research in mice has found that there may be a way to mitigate some of the effects of female reproductive aging and increase fertility as we reach the years approaching 40 and beyond.The Stats on InfertilityApproximately 12% of women in the United States in their reproductive years have trouble getting pregnant or maintaining a pregnancy, reports the Centers for Disease Control and Prevention (CDC). Additionally, one in four couples has been affected by infertility worldwide, suggests finding from the World Health Organization (WHO).After reaching age 35, the likelihood of having infertility struggles jumps to one out of every three women. With statistics like these, it's no wonder that women and couples are looking for solutions to help increase fertility. However, advancing maternal age isn't the only reason behind the rise in infertility rates. Given that the female reproductive system is made up of the ovaries, fallopian tubes, and uterus, dysfunction, or disorders in any of them could contribute to reduced fertility. Other factors that can impact fertility include:・Obesity・Exposure to endocrine disruptors (like BPA in plastics)・Polycystic ovarian syndrome・Endometriosis・Hypothyroidism・Other underlying medical conditionsPlus, it's important to mention that men also play a crucial role in fertility; 20-30% of infertility cases can be linked back to issues with the male reproductive systems as well.Although there are options for those struggling with infertility, like assisted reproductive technologies that include in vitro fertilization (IVF), these treatments can be costly, invasive, pose a risk, and don't necessarily have a high success rate, especially as women age.However, there may be a new option on the horizon to help increase fertility. Emerging research has found that a low supplemental dose of nicotinamide mononucleotide (NMN) was able to restore fertility in aging female mice. NMN is a precursor to NAD+, a crucial coenzyme needed for healthy aging, DNA repair, and metabolism.As NAD+ levels decline with age, so does the quality and number of oocytes, which is the technical name for egg cells before they fully mature into eggs. Oocytes are not self-renewing cells - the amount a woman has at birth will be the highest number she ever has. Due to this finite number of cells that decrease year after year, a woman's fertility is largely based on both the number and the quality of oocytes she has left. While there's no way to increase the number of oocytes, we can improve the quality and functioning of the ones remaining.Based on this, the researchers behind this new study, published in the February 2020 issue of Cell Reports, hypothesized that boosting NAD+ in the oocytes of mice through supplemental NMN may be a low-risk and non-invasive method to increase fertility.What Did the Researchers Find?In this study, the researchers tested several different ways in which NMN could be used to improve fertility or oocyte quality, both of which begin to decline at around eight months of age in mice. Let's take a look at the three most important results that were reported in Cell Reports:1. NMN supplementation increased NAD+ in oocytes.When comparing mice between four and five weeks old to 12-month old mice, the older mice had reduced levels of NADPH in their oocytes, as is to be expected with increasing age. NADPH, a required cofactor for anabolic reactions, is the phosphorylated form of NAD+ (meaning it has a phosphate group attached). The researchers measured this form rather than NAD+ due to bioanalytical challenges of measuring NAD+ in oocytes; nonetheless, the function of both NAD+ and NADPH are very similar - both decline as we (and mice) age. After the 12-month old female mice received water that was treated with NMN at 2 g/L for four weeks, levels of NADPH in their oocytes did increase significantly, indicating that NMN was able to restore the age-related decline in NAD+ seen in the female reproductive system.2. The low dose demonstrated a greater impact on fertility than the high doses.The most interesting outcomes of the study resulted when the researchers gave 13-month old mice two different doses of NMN for four weeks. At 13 months, these mice are very near the end of what's considered their "reproductive years."The low-dose group received 0.5 g/L of NMN-treated water, while the higher-dose group received 2 g/L of NMN in their water. After introducing male mice for breeding, the low-dose group saw significant increases in the number of live births, as well as reductions in the time it took to get pregnant. In contrast, the higher-dose group did not see the same benefits of increased fertility.3. NMN supplementation improved IVF outcomes.Lastly, the researchers also looked at how the oocytes of aged female mice responded to IVF when receiving NMN treatment. After the 12-month-old mice received 2 g/L NMN in water for four weeks, their oocytes had larger diameters - oocytes with smaller diameters are linked to worse outcomes after IVF. When the oocytes of the mice received IVF plus NMN-water for two, seven, 14, or 28 days, a longer treatment of NMN led to improved inner cell mass size, which is linked to improved fertility outcomes after IVF.Similarly, IVF was performed using in vivo oocytes from 12-month-old or 4-week-old female mice, and the embryos were then cultured with or without NMN. After supplementation with NMN, the embryos from the oocytes of the older mice had improved blastocyst formation, but the younger mice did not see similar benefits. This improvement in embryo development solely in the aging mice suggests that NMN supplementation during IVF in younger years may not provide the same therapeutic benefits, likely because NAD+ levels have not yet declined.The Caveats to ConsiderWhile this study does provide encouraging and hopeful results for improving fertility, there are a couple of important points to consider when interpreting the research.Less is MoreThese results of the study suggest that while a larger dose of NMN did benefit oocyte quality by increasing NAD+ levels, it did not actually improve fertility and birth outcomes in the same way the lower dose did.This could be due to an upper limit of NMN tolerability or an increase in nicotinamide, a degradation product of NMN that inhibits sirtuins, which are a family of NAD+-dependent proteins that regulate cellular health and promote healthy aging. Although nicotinamide (the amide form of vitamin B3) does have anti-inflammatory and neuroprotective benefits, it may also increase oxidation when consumed or produced in excess. If NMN was consumed in excess of what is needed, then nicotinamide would be produced as a byproduct in excess as well.In regards to the current study, although the fertility benefits were not seen in the higher dose group, it's important to note that no adverse effects were observed either. Moreover, the aging mice in this study did not have to take NMN long before seeing benefits: 50% of the mice on the low dose of NMN achieved pregnancy by the third week of supplementation, indicating that favorable fertility outcomes may be achieved in a short amount of time.But Humans are Not MiceYes, we know that humans are not mice, and mice are not humans. We can't automatically extrapolate data from mouse studies and assume that they will apply to humans - especially a specific subset of humans like reproductively-aging females.But there are several reasons that mice have been used in medical research for decades. Perhaps surprisingly, humans and mice have very similar genomes, genetics, anatomy, and physiology, which make comparing results a bit more useful. In regards to this study, mice have very similar reproductive systems to humans, albeit a shorter gestation period. Mice also have much shorter lifespans than humans, allowing us to study disease development and longevity more easily, as one mouse year equates to approximately 30 human years.Again, although we can't directly apply these results to us, as humans, the researchers of this study acknowledge that this may be a clinically relevant treatment for infertility by improving outcomes of both natural fertility and IVF.A low dose of NMN may be an appropriate and simple solution to helping the millions of women worldwide who want to get pregnant yet have been struggling in their fertility journey for too long. As always, further research - especially in human clinical trials - is warranted before anything can be said definitively. Nonetheless, the risk of taking a low dose NMN supplement is low, and the benefits to fertility may be high.Your Takeaway: Can NMN Increase Fertility?・In reproductively aging mice, a low dose of NMN was able to increase birth rates and reduce the time to pregnancy more than a higher dose of NMN・The higher dose of NMN was able to restore the age-related decline in NAD+ levels and oocyte quality of aging female mice, as well as improve outcomes of IVF in cultured media・In the future, we may see that low-dose NMN supplementation could be a non-invasive and low-risk way to increase fertility or allow for pregnancies at an older age to remain viable, compared to the invasive and expensive IVF treatment・Research on this topic in humans is needed before any definitive claims can be made about the impact of NMN supplementation on improving or increasing fertility outcomes  

Nicotinamide mononucleotide (NMN) is showing promising health and longevity benefits due to its unique ability to convert into oxidized nicotinamide adenine dinucleotide (NAD+), a coenzyme found in all cells that assists with energizing everyday bodily functions such as energy production, metabolism, and gene expression. As we age, NAD+ levels naturally decline and our cells stop dividing, which contributes to the loss of function seen in people who are aged and those who suffer from chronic disease. This process is called cell senescence. By increasing levels of NAD+ in our system by taking NMN supplements, we can offset senescence and improve our cellular health.The most well-known NMN benefits include:・Improved mitochondrial healt・Increased energy productio・Cognitive improvemen・Reduced obesit・Healthy metabolis・Increased fertilit・Healthy gene expressionJust as people’s immunity is impacted by different variables like genetics, environmental influences, diet, and lifestyle, NMN supplements are also composed differently. You should know what to look for in NMN supplements and be aware of which products blend best with your body and personally provide the most value. Let’s take a look at how you can determine what the best NMN supplement is for you.How to Choose the Best NMN Supplement for You: What to Look For1. A Supplier with an Excellent ReputationQuality NMN comes from quality suppliers. But how can you tell a company is reputable? You can check the Better Business Bureau to see how long the company has been in business, what their current rating is, and if there have been any complaints filed against them. An esteemed company will have good reviews and ratings across multiple platforms and is a great place to start when deciding on the right product so you can get the benefits of NMN. Check the company website or do an internet search to see if they have accumulated positive NMN supplement reviews.2. Good Manufacturing Facility PracticesA respected NMN supplier will have ethical operating procedures when it comes to manufacturing. A facility producing NMN should be FDA-registered and FDA-compliant in current Good Manufacturing Practice (GMP) regulations. Being GMP-certified means the FDA has found the company’s facilities, equipment, and ability to manufacture NMN products up to par with the standard regulations. You may also consider looking into whether the facility is climate-controlled. NMN supplements can quickly degrade at high temperatures, which is why they should be produced in a facility where appropriate temperatures are kept during the manufacturing process.3. Third-Party TestingOne of the most important things to check when determining which NMN supplement is the best is whether or not the manufacturing company submits its product for independent, third-party testing. Testing by a non-biased party will ensure the product is pure (99% or higher) pharmaceutical-grade NMN, free of heavy metals. You can check the supplier’s website for third-party testing information, or contact their customer service directly. Verification of third-party testing is a simple way to ensure you’re buying from a reputable source. Any company using third-party testing should be happy to share that information with you.4. Product PurityAs previously mentioned, the best NMN supplements will have 99% purity or higher. It will also not contain any fillers or byproducts such as GMOs, dairy, egg, soy, gluten, artificial chemicals, heavy metals, or solvents used in the actual processing of the product. Check labels for any of these ingredients, or you can always directly contact the company to ask about their NMN production process.5. PricingIt’s always tempting to try to save money every chance you can get, but with NMN specifically, you get what you pay for. Low-cost NMN will likely be food-grade, not pharmaceutical grade, which means the NMN benefits aren’t the same. It comes back to the involved process required to create a product with 99% purity or higher. If the price is low, the percentage of NMN is likely also low — if it exists at all. Considering your budget is important when determining where to buy NMN supplements, but you may end up paying more in the long run when opting for lower-priced NMN products if you don’t see any health benefits from them.6. Consumer-Satisfaction GuaranteeHighly regarded NMN supplement companies usually provide some kind of guarantee of compensation should you find yourself not fully satisfied with the results of your purchase. Check the fine print on a supplier’s website or call the company to verify whether they afford any money-back guarantees if returned by a specific date. For example, some companies may offer a 30-day money-back guarantee, which should be enough time to determine if the NMN supplement product is a good fit for you.7. Product ResearchWith NMN being more heavily researched for its benefits to overall health and longevity as a necessary NAD+ precursor, the chances of a particular NMN product being used in human clinical trials exist. Only NMN products whose quality and purity can be verified are used for studies, so you may want to see if the product you’re interested in is being considered or used for research purposes. While most companies proudly display this online, you can always call customer service to double-check if you can’t locate that information yourself.8. Form of DeliverySupplementary NMN can be purchased as powder, lozenges, tablets, and capsules, each having a unique ability to get into your system in different ways. When figuring out how to choose NMN supplements, your personal preference is really the key. If tablets and capsules are difficult to swallow, starting with NMN powder or a lozenge may be the best option for you. For convenience purposes while traveling, for example, an easy-to-carry pill or lozenge may provide the best solution. A good company will likely have a variety of NMN forms available to suit your needs, so consider which form may be best for you. No matter which form you take, NMN is absorbed from the gut and into the blood within two to three minutes, and completely absorbed into tissue within 15 minutes, according to a study in Biomolecules. Once in the liver, it is then converted and stored as NAD+ and persists for 30 minutes.Key TakeawaysFinding the best NMN supplement to assist in your efforts to recapture and maintain your youth can be easy when you know what questions to ask and what answers to listen for. A supplier with a long-standing, good reputation that adheres to FDA regulations will most likely provide you with a high-quality, third-party tested, pharmaceutical-grade NMN product. Don’t forget to read NMN supplement reviews, and when in doubt, go directly to customer service with any concerns or questions you may have. When you get close to committing to a purchase, remember to check for any satisfaction guarantees to confirm you are making a risk-free, sound investment in your health.ReferencesCenter for Drug Evaluation and Research. (n.d.). Current Good Manufacturing Practice (CGMP) Regulations. Retrieved June 15, 2020, from https://www.fda.gov/drugs/pharmaceutical-quality-resources/current-good-manufacturing-practice-cgmp-regulationsOffice of Regulatory Affairs. (n.d.). Registration and Listing. Retrieved June 15, 2020, from https://www.fda.gov/industry/fda-basics-industry/registration-and-listingPoddar SK, Sifat AE, Haque S, Nahid NA, Chowdhury S, Mehedi I. Nicotinamide Mononucleotide: Exploration of Diverse Therapeutic Applications of a Potential Molecule. Biomolecules