Understand Difference

Exploring the Key Differences Between NAD and NR: Coenzyme vs Precursor

Introduction to Nicotinamide Adenine Dinucleotide and

Nicotinamide Riboside

Metabolism is a vital physiological process that is responsible for converting food and oxygen into energy that the body can use to grow, repair, and function. Enzymes, which are specialized proteins, carry out these complex metabolic reactions.

One coenzyme that plays a crucial role in many of these reactions is Nicotinamide Adenine Dinucleotide (NAD), which participates in a multitude of cellular processes. This article will provide an overview of NAD and its precursor

Nicotinamide Riboside (niagen), their characteristics, functions, and importance in pharmacology.

Overview of Nicotinamide Adenine Dinucleotide (NAD)

NAD is a coenzyme that acts as a cofactor for a range of enzymes engaged in essential cellular processes. This molecule is a redox-active coenzyme that facilitates the transfer of electrons within different metabolic pathways and plays a significant role in redox reactions.

It acts as an electron acceptor, receiving a pair of high-energy electrons to transform into its reduced form (NADH), and subsequently delivers them to other metabolic pathways. Furthermore, NAD participates in a myriad of intra and intercellular signaling pathways, affects transcriptional activity by serving as a substrate for critical posttranslational modifications, and plays an essential role in DNA repair, which is necessary to prevent cells from accumulating DNA damage and becoming cancerous.

Overview of

Nicotinamide Riboside (niagen)

Nicotinamide Riboside is a vitamin B3 precursor that can be converted into NAD through a complex salvage pathway. It has gained popularity recently due to its alleged benefits in slowing down aging and improving mitochondrial function.

Elysium Health, a company founded by Dr. Leonard Guarente, sells commercially available NR supplements under the brand name Basis. This supplement is marketed as a way of boosting NAD levels and supporting optimal cellular function.

Molecular Weight and Discovery of NAD

NAD was discovered by biochemists Arthur Harden and William John Young in 1906 while investigating the mechanism of fermentation in yeast cells. They found a heat-stable growth factor in yeast extract that was essential for healthy cell growth.

After further experiments, they identified this growth factor as a phosphate-containing compound, which came to be known as NAD. The molecular weight of NAD is 663.43g/mol.

It is a dinucleotide consisting of two mononucleotides linked by their phosphate groups, a nicotinamide, and an adenine nucleobase. The two forms of NAD are NAD+ and NADH, with NAD+ being the oxidized form and NADH the reduced form.

Chemical Structure and Forms of NAD

The chemical structure of NAD is composed of three parts: the nicotinamide ribose, the adenine nucleobase, and the phosphate groups. The nicotinamide ribose and adenine nucleobase are attached to the first phosphate group via a bond, creating the dinucleotide.

In the oxidized form, NAD+ has two phosphate groups on one end and the nicotinamide ribose and adenine nucleobase on the other. However, in the reduced form, NADH has a hydride ion instead of the second phosphate group.

Functions of NAD in Metabolism and Other Cellular Processes

NAD plays an essential role in cellular respiration, glycolysis, the TCA cycle, and the electron transport chain. It functions in these pathways by accepting and donating electrons, facilitating redox reactions, and generating ATP, the energy currency of the cell.

Another cellular process that NAD is involved in is posttranslational modifications where it acts as a substrate for critical enzymes such as poly(ADP-ribose) polymerases (PARPs) and sirtuins. These enzymes transfer ADP-ribose or remove acetyl groups from lysine residues, which modifies protein activity and affects transcriptional activity.

Additionally, NAD+ serves as a defense system in stress responses, oxidative damage, and circadian rhythm regulation.

Synthesis and Transformation of NAD

NAD can be synthesized from two main sources: the salvage pathway and the de novo pathway. The salvage pathway is a recycling method that reuses the nicotinamide that is left after NAD+ is consumed in metabolic reactions to create new NAD.

In contrast, the de novo synthesis pathway uses tryptophan and aspartic acid to create a new NAD molecule. Moreover, NAD can be transformed into several forms such as NADP, NMN, and NR.

NADP is used in anabolic processes such as lipid and nucleotide synthesis, while NMN and NR are intermediates in the biosynthesis of NAD. Importance of NAD+ and NADH in Pharmacology

NAD+ and NADH have vast potential in pharmacology as their activity is essential for a range of cellular processes.

However, the most promising pharmacological potential lies in their impact on diseases such as cancer, Alzheimer’s, Parkinson’s disease, and tuberculosis. Researchers have found that modulating NAD+ levels can help impede the growth of cancer cells and reduce the symptoms of neurodegenerative diseases.

In conclusion, NAD is a vital coenzyme that is an essential component in numerous metabolic pathways. It plays a crucial role in redox reactions, DNA repair, posttranslational modifications, and circadian rhythms.

Nicotinamide Riboside is a precursor to NAD that has gained popularity due to its potential benefits in anti-aging and mitochondrial support. Understanding the essential properties of NAD and its forms can help us develop new pharmaceutical therapies to alleviate the symptoms of specific disease states.

Nicotinamide Riboside

Nicotinamide riboside (NR) is a pyridine nucleoside found in milk, whey protein, and other dietary sources. It is a precursor to NAD+ biosynthesis and has gained recognition in recent times as a promising compound for extending health span and lifespan.

In this article, well examine the discovery, molecular structure, role as NAD+ precursor, and benefits and controversies of NR to help understand its potential in human health applications. Discovery and Molecular Weight of

Nicotinamide Riboside

In 1944, Wendell Gingrich and Fritz Schlenk discovered nicotinamide riboside in beef liver.

They identified it as a growth factor necessary for the growth of Haemophilus influenza, a bacterium responsible for causing influenza and pneumonia. NR was later found in milk and both plant and animal tissues.

Nicotinamide riboside has a molecular weight of 255.25g/mol, consisting of the pyridine-rich nucleoside ribose and a nicotinamide moiety derived from vitamin B3. NR can donate a single ribose unit to form NAD+ through unique salvage pathways in humans.

Role of

Nicotinamide Riboside As a Precursor to NAD+

Nicotinamide riboside plays a vital role in the biosynthesis of NAD+ in humans. It is converted into NAD+ through a new biosynthesis pathway that bypasses the intermediates of conventional pathways.

NR is converted into nicotinamide mononucleotide (NMN) by nicotinamide riboside kinase (NRK), and then NMN is converted into NAD+ by NMN adenylyltransferase (NMNAT). Eventually, NAD+ is catabolized to form NADH, a reduced form of NAD+.

NR has been used in research studies for its unique properties compared to other NAD+ precursors. NR is beneficial as a treatment that can raise NAD+ levels in various tissues in animals.

NR was also found to activate sirtuins, a family of longevity enzymes that can improve lifespan in a range of species. ChromaDex, a leading manufacturer of NR supplements, has marketed its NAD+ precursor under the brand name Niagen.

Elysium Health, a company founded by Dr. Leonard Guarente, sells another commercial product, Basis, which promises to raise NAD+ levels by increasing nicotinamide riboside consumption. Benefits and Controversies Regarding

Nicotinamide Riboside Supplements

Nicotinamide riboside supplements have received extensive attention regarding their possible health benefits.

Researchers are studying NRs beneficial effects on slowing down the aging process, alleviating age-related diseases, and improving mitochondrial function. There are reported benefits of NR in reversing muscle decline, promoting insulin sensitivity, and reducing the effects of neurodegeneration.

However, critics argue that these claims are unfounded and unsupported by clinical data. There are concerns that high doses of NR or other NAD+ precursors could cause harm to the liver or other organs.

Moreover, a recent patent dispute arose between ChromaDex and Elysium Health, the leading manufacturers of NR supplements. The legitimacy of the patent was challenged by Elysium Health, and the trial eventually concluded that the patents for the use of NR were valid and that Elysium Health had a license to sell it.

Similarities between Nicotinamide Adenine Dinucleotide and

Nicotinamide Riboside

Both NAD+ and NR share a common precursor, nicotinamide. NAD+ is synthesized from niacin or dietary tryptophan, while NR serves as an alternative precursor to NAD+.

Both molecules play crucial roles in metabolic reactions, electron transfer, and redox reactions that generate ATP. Moreover, NAD+ and NR are essential in human health and have unique benefits.

NR is known for its effects in raising NAD+ levels and activating sirtuin activity. NAD+ is required for the proper functioning of essential enzymes involved in DNA repair, cell differentiation and death, and energy metabolism.

Both NAD+ and NR also require proper storage conditions. They should be kept tightly sealed in a cool and dry place, away from direct sunlight, to ensure their stability.


Nicotinamide Riboside is a promising NAD+ precursor that has garnered significant attention for its potential benefits. NR can replenish NAD+ levels in a different manner to other NAD+ precursors, and results from animal testing show great promise in mitigating age-related diseases and improving lifespan.

Despite some concerns and controversies among NR supplements, NR continues to show potential in benefiting human health. Differences between Nicotinamide Adenine Dinucleotide and

Nicotinamide Riboside

Nicotinamide Adenine Dinucleotide (NAD) and

Nicotinamide Riboside (NR) are two molecules used in a wide variety of cellular processes.

Despite being closely related, they have distinct roles, structures, and functions. In this article, we will explore the differences between these two molecules, with a focus on their distinctive roles, size differences, and metabolic pathways.

Distinction between Coenzyme and Precursor Roles

NAD and NR have different roles in the cellular metabolism, and it is important to distinguish between their functions. NAD is a central coenzyme, meaning that it directly participates in metabolic reactions, such as glycolysis, the tricarboxylic acid cycle (TCA), and oxidative phosphorylation, by shuttling electrons between enzymes.

NAD is also involved in signaling pathways, such as posttranslational modifications and DNA repair.

On the other hand, NR is an alternative precursor to NAD that indirectly contributes to its synthesis through distinct pathways.

NR is converted into NMN by NR kinase, which is then acted upon by NMN adenylyltransferase to form NAD+. In contrast to NAD, NR is not a coenzyme but a precursor to it.

Therefore, the primary role of NR is to support NAD+ biosynthesis, where NAD+ acts as a coenzyme in cellular metabolism. Size Differences between NAD and

Nicotinamide Riboside

NAD and NR exhibit significant size differences, which are evident from their chemical structures.

NAD is a larger and more complex molecule with a molecular weight of 663.43g/mol, while NR is much smaller and simpler, with a molecular weight of 255.25g/mol.

The size of NAD is due to its dinucleotide structure, which consists of two nucleotides joined by a phosphate group.

In contrast, NR refers to a single nucleoside, consisting of a ribose sugar and a pyridine moiety, which is the nicotinamide.

Metabolic Pathways

Both NAD and NR are synthesized through different metabolic pathways. The predominant pathways for NAD biosynthesis are the de novo pathway and the salvage pathway.

The de novo pathway utilizes amino acid precursors, such as tryptophan and aspartic acid, to generate NAD. In contrast, recycling available nicotinamide molecules through the salvage pathway is the fundamental pathway source for NAD biosynthesis.

NR’s primary biosynthetic pathway is through the salvage pathway, where it participates in the recycling of nicotinamide to form NAD+. After NR is taken up by cells, it is converted to NMN by NR kinase, and then, NMN is converted to NAD+.

Metabolic pathways associated with NAD and NR differ significantly, as NAD functions downstream in central metabolic pathways, while NR operates upstream as a precursor to NAD biosynthesis. Thus, even though NR is an alternative precursor to NAD+, metabolic pathways associated with NR cannot replace those of NAD.


NAD and NR are two molecules with distinct roles and structures in cellular metabolism. NAD serves as a central coenzyme in a variety of metabolic pathways, while NR acts as an alternative precursor to NAD to support its biosynthesis.

The size of these molecules differs significantly, with NAD being larger and more complex than NR, which refers to a single nucleoside. The metabolic pathways for NAD and NR biosynthesis also differ.

Understanding these differences is crucial in interpreting the significance of these two molecules within metabolism and human health research. In conclusion, Nicotinamide Adenine Dinucleotide (NAD) and

Nicotinamide Riboside (NR) are two molecules that play distinct roles in cellular metabolism.

While NAD functions as a central coenzyme, NR acts as an alternative precursor to NAD biosynthesis. They differ in size, with NAD being larger and more complex than NR.

Understanding the differences between NAD and NR is crucial for comprehending their contributions to cellular processes and their potential impact on human health. NAD’s central role in metabolic pathways and NR’s involvement as a precursor highlight the intricate mechanisms underlying cellular function.

Further research in this area may provide valuable insights into aging, disease prevention, and therapeutic interventions.

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