The short version of NAD+ fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-04-05 and is reviewed periodically as new material appears.
Nicotinamide mononucleotide, abbreviated NMN, is a naturally occurring nucleotide. Its structure combines a nicotinamide ring, a ribose sugar, and a phosphate group. The compound exists in cells as an intermediate in the production of nicotinamide adenine dinucleotide, a central redox cofactor. NMN is distinct from nicotinamide riboside, another related pyridine nucleotide, although the two compounds can converge in metabolic pathways. Its chemical formula is C11H15N2O8P, and it carries a net negative charge at physiological pH.
In the salvage pathway, NMN is generated from nicotinamide and 5-phosphoribosyl-1-pyrophosphate by the enzyme nicotinamide phosphoribosyltransferase. A second route produces NMN from nicotinamide riboside through phosphorylation by nicotinamide riboside kinases. NMN is then converted to NAD+ by nicotinamide mononucleotide adenylyltransferases, often called NMNAT enzymes. This stepwise route allows cells to recycle nicotinamide and maintain NAD+ levels under changing metabolic conditions. The relative contribution of each route varies by tissue, species, and physiological state, and it remains an active area of research.
Research on NMN has expanded because NAD+ concentrations decline with age in some tissues and because NAD+ participates in energy metabolism, DNA repair, and signaling. Animal studies have reported changes in NAD+ levels after NMN administration, but human data are more limited and often focus on safety, pharmacokinetics, and biomarker changes. Questions remain about oral absorption, tissue distribution, and whether changes in blood NAD+ reflect changes inside specific organs. NMN is not an approved drug, and claims about its clinical effects should be distinguished from established biochemical findings.
Nicotinamide mononucleotide, commonly abbreviated NMN, is a naturally occurring nucleotide. Its structure consists of a nicotinamide ring attached to a ribose sugar that carries a phosphate group. The molecular formula is C11H15N2O8P, and the molar mass is about 334.22 grams per mole. In cells, NMN is an intermediate in the salvage pathway that recycles nicotinamide to maintain NAD+ levels. It is not the same compound as NAD+, although it is a direct precursor in one enzymatic step.
Inside cells, the enzyme nicotinamide phosphoribosyltransferase, or NAMPT, converts nicotinamide and a ribose-phosphate donor into NMN. A second enzyme, NMN adenylyltransferase, then converts NMN into NAD+. NAD+ participates in redox reactions and serves as a substrate for signaling enzymes such as sirtuins, PARPs, and CD38. Because NAD+ levels tend to decline with age in many organisms, NMN has drawn interest as a possible way to influence that decline. Whether oral NMN reliably raises NAD+ in human tissues, and whether any such change modifies disease risk, remain open research questions.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C11H15N2O8P | Pyridinium nucleotide; free acid form |
| Molar mass | 334.22 g/mol | Free acid; salt forms differ |
| Appearance | White to off-white powder | Typical reference material |
| Solubility class | Water-soluble | Hygroscopic under humid conditions |
| Common synonyms | Nicotinamide mononucleotide; NMN | Distinct from nicotinamide riboside |
Nicotinamide mononucleotide, usually shortened to NMN, is a naturally occurring nucleotide. Its structure consists of a nicotinamide base linked to a ribose sugar that carries a phosphate group. In cells, NMN serves as an intermediate in the salvage pathway that produces nicotinamide adenine dinucleotide, or NAD+. Because NAD+ participates in many oxidation-reduction reactions, NMN sits near central metabolic processes. The compound is not a drug in most jurisdictions and is discussed mainly in biochemistry and nutrition research.
The term NMN commonly refers to the beta isomer, in which the nicotinamide group is attached to the ribose through a beta-glycosidic bond. Commercial material may be supplied as the free acid or as a salt, such as a sodium salt, which affects molecular weight and water solubility. Related compounds include nicotinamide riboside and NAD+ itself, but these are distinct molecules with different formulas and cellular handling. Laboratory research often uses the beta form because it matches the naturally occurring configuration found in biological systems.
Dietary sources of NMN include small amounts in certain vegetables, fruits, and other foods, although exact values vary by sample and method. Endogenous NMN concentrations are tightly regulated and often low, making measurement in blood or tissues technically demanding. After oral intake, NMN is thought to be rapidly metabolized in the intestine and liver, and intact NMN may not reach all tissues at high levels. Some rodent studies report increases in tissue NAD+ after oral NMN, while human data remain limited and sometimes rely on blood NAD+ metabolites rather than direct tissue measures.
Research on NMN has focused on aging, metabolic regulation, exercise capacity, and insulin sensitivity, but findings are preliminary. Many human trials are small, short in duration, and use different endpoints, which complicates comparison across studies. No national regulator has approved NMN as a therapeutic drug for any indication. In some countries it is sold as a supplement or research chemical, while other jurisdictions have questioned its status under food or supplement laws. Claims about extending human lifespan or reversing aging are not supported by established clinical evidence.
NMN is present in small amounts in various foods, including certain vegetables, fruits, and milk, though dietary quantities are generally low. Laboratory research often uses synthetic or enzymatically produced NMN. The compound has drawn interest because NAD+ levels decline with age in some tissues and because restoring NAD+ may affect metabolism in animal models. Whether oral NMN produces meaningful NAD+ increases in humans and whether such changes translate into health benefits are not fully established.
Nicotinamide mononucleotide, abbreviated NMN, is a naturally occurring nucleotide. Its structure combines a nicotinamide base with a ribose sugar and a phosphate group. Within cells, NMN sits on the biosynthetic route that recycles nicotinamide back into nicotinamide adenine dinucleotide, or NAD+. Because NAD+ participates in redox reactions and signaling, enzymes that produce and consume it influence many metabolic processes. The compound is therefore best described as an intermediate rather than a final signaling molecule.
In the canonical salvage pathway, nicotinamide phosphoribosyltransferase, known as NAMPT, transfers a phosphoribosyl group to nicotinamide and releases NMN. A second enzyme, NMN adenylyltransferase, then attaches an adenylyl group to NMN to form NAD+. Alternative routes exist, including a pathway that uses nicotinamide riboside and its phosphorylated forms. The relative contribution of extracellular NMN to intracellular NAD+ pools remains an area of active investigation, and the roles of specific transporters and enzymes are not completely defined.
The RNAi pathway is a naturally occurring process found in many eukaryotes. It is initiated by the enzyme Dicer, which cleaves long double-stranded RNA (dsRNA) molecules into short double-stranded fragments of approximately 21 to 23 nucleotide siRNAs. Each siRNA is unwound into two single-stranded RNAs (ssRNAs), the passenger (sense) strand and the guide (antisense) strand. The passenger strand is then cleaved by the protein Argonaute 2 (Ago2). The passenger strand is degraded and the guide strand is incorporated into the RNA-induced silencing complex (RISC). The RISC assembly then binds and degrades the target mRNA. Specifically, this is accomplished when the guide strand pairs with a complementary sequence in a mRNA molecule and induces cleavage by Ago2, a catalytic component of the RISC. In some organisms, this process spreads systemically, despite the initially limited molar concentrations of siRNA. RNAi is a valuable research tool, both in cell culture and in living organisms, because synthetic dsRNA introduced into cells can selectively and robustly induce suppression of specific genes of interest. RNAi may be used for large-scale screens that systematically shut down each gene (and the subsequent proteins it codes for) in the cell, which can help to identify the components necessary for a particular cellular process or an event such as cell division. The pathway is also used as a practical tool for food, medicine and insecticides.
=== Enzyme regulation (activation and inhibition) === The first example of protein regulation by phosphorylation to be discovered was glycogen phosphorylase. Nobel laureates Edmond H. Fischer and Edwin G. Krebs described how phosphorylation of glycogen phosphorylase b converted it to the active glycogen phosphorylase a. It was soon discovered that glycogen synthase, another metabolic enzyme, is inactivated by phosphorylation. Phosphorylation of the enzyme GSK-3 by AKT (Protein kinase B) as part of the insulin signaling pathway. Phosphorylation of Src tyrosine kinase by C-terminal Src kinase inactivates Src by inducing a conformational change which masks its kinase domain. Phosphorylation of the H2AX histones on serine 139, within two million bases (0.03% of the chromatin) surrounding a double-strand break in DNA, is needed for repair of the double-strand break. Phosphorylation of methylpurine DNA glycosylase at serine 172 is required for base excision repair of alkylated base damage.
Both sides agreed to build a "constructive strategic and stable relationship between China and the United States based on respect, fairness, and equality." Both sides agreed to support each other in successfully hosting the APEC Leaders' Informal Meeting and the G20 Leaders' Summit. The two heads of state expressed their intention to attend the meetings hosted by the other. The two heads of state agreed that Iran should uphold its commitment not to develop nuclear weapons and that no country or organization should impose tolls on international waterways. The two heads of state recalled that China and the United States were allies in World War II and fought side by side to win the war. The two heads of state acknowledged the positive role of the China–US trade consultation mechanism and the results of the consultations between the two trade teams, including the establishment and advancement of mechanisms such as the Council of Trade, the reaching of a $30 billion reciprocal tariff reduction arrangement, and the extension of the Kuala Lumpur trade consultation results, and instructed that these be implemented. Cooperation between Chinese and American drug enforcement agencies has yielded visible results. Recently, the two sides have worked closely together to crack multiple cases involving new psychoactive substances and precursor chemicals, arresting dozens of suspects in both countries. Both sides agreed to establish a China-US artificial intelligence dialogue to exchange views on the risks and benefits of AI. The next dialogue will be held in November this year.
Sources: en.wikipedia.org
== Career == Goodacre joined the University of Oxford as a research fellow in 1999. She was a research fellow at the University of East Anglia from 2002. She was described by the BBC as Spider Woman. As of 2018, Goodacre is based at the University of Nottingham, where she founded the SpiderLab in 2007 and leads the ArachNotts research group. As a geneticist, Goodacre studies the evolution, population and conservation of spiders. She monitored the mating behaviour and sex ratio of the linyphiid spider Pityohyphantes phrygianus with Bengt Gunnarsson at the University of Gothenburg. She also studied the silk of Mygalomorphae spiders and the genetic diversity of spider silk genes and found evidence for antimicrobial activity in the silk of common house spiders. She found that Erigone atra, a pest controlling spider, uses long-distance airborne dispersal. Goodacre contributed to the 2011 book Spider Physiology and Behaviour: Physiology. In 2015 Goodacre reported that spiders could survive "sailing" across oceans. ArachNotts study the diving bell spider and its silk, which it uses to build a diving bell in which it stores air underwater, and have so far identified some of the silk genes used by this spider. They also work on the relationship between spiders and the microbes that they carry with them, including the mating behaviour and sex-ratio of offspring, the ecology and biological control potential of spiders in agriculture and the use of genetic tools in the conservation of the endangered raft spider.
=== Economics === Copra production begins on coconut plantations. Coconut trees are generally spaced 9 m (30 ft) apart, allowing a density of 100–160 coconut trees per hectare. A standard tree bears around 50–80 nuts a year, and average earnings in Vanuatu (1999) were US$0.20 per kg (one kg equals 8 nuts)—so a farmer could earn approximately US$120 to US$320 yearly for each planted hectare. Copra has since more than doubled in price, and was quoted at US$540 per ton in the Philippines on a CIF Rotterdam basis (US$0.54 per kg) by the Financial Times on 9 November 2012. In 2017 the value of global exports of copra was $145-146 Million. The largest exporter was Papua New Guinea with 35% of the global total, followed by Indonesia (20%), Solomon Islands (13%) and Vanuatu (12%). The largest importer of copra is the Philippines, which imports $93.4 Million or 64% of the global total. A very large number of small farmers and tree owners produce copra, which is a vital part of their income.
==== Detailed ADH pathway ==== The reaction from ethanol to carbon dioxide and water proceeds in at least 11 steps in humans. C2H6O (ethanol) is converted to C2H4O (acetaldehyde), then to C2H4O2 (acetic acid), then to acetyl-CoA. Once acetyl-CoA is formed, it is free to enter directly into the citric acid cycle (TCA) and is converted to 2 CO2 molecules in 8 reactions. The equations:
Sources: en.wikipedia.org
==== Neuroimaging ==== Although global abnormalities in white matter and grey matter are not consistently associated with cannabis use, reduced hippocampal volume is consistently found. Amygdala abnormalities are sometimes reported, although findings are inconsistent. There is evidence that amygdala volume is smaller in cannabis users. Cannabis use is associated with increased recruitment of task-related areas, such as the dorsolateral prefrontal cortex, which is thought to reflect compensatory activity due to reduced processing efficiency. Cannabis use is also associated with downregulation of CB1 receptors. The magnitude of down regulation is associated with cumulative cannabis exposure, and is reversed after one month of abstinence. There is limited evidence that chronic cannabis use can reduce levels of glutamate metabolites in the human brain.
However, some studies have found it to have a high variability, poor reproducibility, and low diagnostic sensitivity. It is also sensitive to various factors such as caffeine and medications, and the iontophoresis procedure may cause skin irritation and discomfort. QSART requires highly specialized equipment needing regular calibration, a humidity- and temperature-controlled room, and trained personnel.
2014 (ongoing): Nepal and Bangladesh, neonatal exposures, found in umbilical cord blood. 2019 Kenya: five brands of maize flour recalled due to contamination. 2021 US: Contamination of pet food manufactured by Midwestern Pet Food, causing the deaths of at least 70 dogs. 2021 Sri Lanka: contaminated coconut oil released for public consumption by the local government.. 2023 Makueni County, Kenya: In a cross-sectional study was used to determine the dietary aflatoxin exposure of 170 lactating mothers breastfeeding children aged 6 months and below. This involved the aflatoxin analysis of maize-based cooked food sample which was in their staple foods. Aflatoxins were determined using high-performance liquid chromatography and enzyme-linked immunosorbent assay. About 46% of the mothers were from low-income households, and 48.2% had not attained the basic level of education. A generally low dietary diversity was reported among 54.1% of lactating mothers. Food consumption pattern was skewed towards starchy staples. Approximately 50% never treated their maize, and at least 20% stored their maize in containers that promote aflatoxin contamination. Aflatoxin was detected in 85.4% of food samples. The mean of total aflatoxin was 97.8 μg/kg (standard deviation [SD], 57.7), while aflatoxin B1 was 9.0 μg/kg (SD, 7.7).
Alanine can also be used as a precursor of glyceroneogenesis because alanine can be degraded to pyruvate. Alanine will degrade to pyruvate by transferring its amino group to 2-oxoglutarate with an enzyme called alanine aminotransferase. Alanine aminotransferase cleaves off the amino group from alanine and binds it to 2-oxoglutarate, generating pyruvate from alanine, and glutamate from 2-oxoglutarate. Pyruvate generated from alanine will enter glyceroneogenesis and generate glycerol 3-phosphate. Glutamate can also enter glyceroneogenesis. Since the key reaction of glyceroneogenesis is the decarboxylation and phosphorylation of oxaloacetate to phosphoenolpyruvate, in theory any biochemical pathway which generates oxaloacetate is related to glyceroneogenesis. For example, glutamate can generate oxaloacetate in 2 steps. Firstly, glutamate can be converted to 2-oxoglutarate with the expense of NAD+ and H2O with the help of glutamate dehydrogenase. Secondly, 2-oxoglutarate can enter the tricarboxylic acid cycle to generate oxaloacetate. Therefore, theoretically any metabolites in the TCA cycle or any metabolites generating the metabolites of the TCA cycle can be used as a precursor of glyceroneogenesis, but glutamate is the only precursor confirmed.
Sources: en.wikipedia.org
NMN stands for nicotinamide mononucleotide. It is a naturally occurring nucleotide and an intermediate in the cellular production of NAD+.
No. NMN is a smaller precursor molecule, while NAD+ is a dinucleotide cofactor used in many reactions. Enzymes called NMNAT convert NMN into NAD+ inside cells.
This question is not fully settled. Some evidence suggests NMN may be dephosphorylated to nicotinamide riboside before uptake, while other studies propose direct transport. Tissue-specific handling in humans remains an open research area.
NMN stands for nicotinamide mononucleotide. It is a nucleotide intermediate in the cellular pathway that produces NAD+, a coenzyme involved in energy metabolism and signaling. NMN is not the same compound as NAD+.