Nicotinamide adenine dinucleotide (NAD+) is essential for life. This coenzyme participates in hundreds of biological processes, including metabolism, energy production, and DNA repair. Over the years, scientific studies have demonstrated that boosting NAD+ levels can enhance healthspan, improve stress resistance, and potentially extend lifespan.
Two key players have emerged as popular NAD+ precursors: Nicotinamide Mononucleotide (NMN) and Nicotinamide Mononucleotide Hydride (NMNH). While NMN has been studied extensively, NMNH is a newer, potentially more powerful alternative.

In this blog, we will explore the differences between NMN and NMNH, their roles in NAD+ biosynthesis, and why NMNH could be the future of NAD+ supplementation.
A Brief History of NMN and NAD+
NAD+ has been at the centre of longevity research for decades. Its importance in cellular function was first highlighted by early studies that demonstrated how increasing NAD+ levels could improve stress resistance and extend lifespan in simple organisms like yeast and fruit flies (Drosophila). In mice, NAD+ enhancement has been shown to delay the onset of age-related diseases and improve overall health.
Nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are two well-researched precursors that can boost NAD+ levels. These molecules are converted into NAD+ inside the body, helping to replenish cellular reserves. Supplementation with NMN has shown numerous health benefits, such as improved muscle function, enhanced energy levels, and protection against age-related decline.
However, the quest to optimise NAD+ supplementation has led researchers to explore NMN's reduced form — NMNH.
What is NMN?
NMN is a direct precursor to NAD+. It is naturally found in small amounts in foods like broccoli, avocado, and edamame. Once ingested, NMN enters cells and is quickly converted into NAD+ by the enzyme NMNAT (nicotinamide mononucleotide adenylyltransferase).
NMN and its Role in NAD+ Production
Increasing NAD+ levels via NMN supplementation has been shown to:
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Improve energy metabolism
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Enhance DNA repair
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Support cardiovascular health
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Protect against age-related deterioration
Despite its promising benefits, NMN’s bioavailability (how efficiently it is absorbed and utilised by the body) has been a subject of debate. Additionally, regulatory challenges in the USA have created uncertainty around NMN’s future availability as a supplement.
NMN in the USA: Regulatory Uncertainty
In the United States, the Food and Drug Administration (FDA) has recently raised concerns over the classification of NMN as a dietary supplement. The regulatory status remains unclear, as ongoing deliberations are yet to yield a final decision. This uncertainty has led consumers and researchers to explore alternative NAD+ precursors that can deliver similar, if not superior, benefits.
Enter NMNH.
Introducing NMNH: The Reduced Form of NMN
Nicotinamide Mononucleotide Hydride (NMNH) is the reduced form of NMN. Unlike NMN, which supports NAD+ synthesis in its oxidised form, NMNH directly contributes to NADH production — the reduced counterpart of NAD+.
Why NMNH is a Game-Changer
Recent studies have shown that NMNH is a more potent NAD+ booster compared to NMN. Here are the reasons that make the NMNH unique:
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Higher Bioavailability: NMNH is up to five times more bioavailable than NMN, meaning the body can absorb and utilise it more efficiently.
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Enhanced NAD+ and NADH Levels: NMNH increases both NAD+ and NADH levels in cells. This dual effect can improve energy production, as NADH is critical for ATP generation via the electron transport chain.
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Metabolic Impact: NMNH has been shown to suppress glycolysis and the TCA cycle, affecting how cells generate energy. This suppression can have downstream effects on ageing and disease prevention.
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Cell Growth Regulation: Unlike NR or NMN, NMNH has been found to inhibit cell growth by causing cell cycle arrest. This could be beneficial in contexts where uncontrolled cell proliferation is a concern.
How is NMNH Made?

Researchers have developed a robust and scalable method to produce NMNH via chemical reduction. The process involves reducing NMN using thiourea dioxide (TDO), a stable and effective reducing agent. This method yields high-purity NMNH, making it suitable for both research and potential therapeutic applications.
Key Findings from NMNH Research
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Increased NADH Levels: NMNH significantly boosts cellular NADH levels, unlike other NAD+ precursors.
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Stable Under Alkaline Conditions: NMNH remains stable in alkaline pH and at low temperatures, though it is less stable at neutral pH compared to NMN.
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Safety in Long-Term Use: Studies have demonstrated that long-term administration of NMNH is safe in mouse models.
NMN vs. NMNH: Which One is Better?
Feature | NMN | NMNH |
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Form | Oxidized | Reduced |
Bioavailability | Moderate | High (5x more bioavailable) |
Boosts | NAD+ | NAD+ and NADH |
Metabolic Effects | Supports energy metabolism | Suppresses glycolysis and TCA cycle |
Cell Growth | No effect on growth | Inhibits cell growth |
Regulatory Status (USA) | Uncertain | Emerging alternative |
Conclusion: The Future of NAD+ Supplementation
As research advances, NMNH is emerging as a powerful alternative to NMN. With its higher bioavailability and dual impact on NAD+ and NADH levels, NMNH could offer superior benefits for those looking to support longevity, energy, and overall health.
Given the regulatory challenges facing NMN in the USA, NMNH provides a promising pathway for continued NAD+ enhancement. As we learn more about NMNH's unique properties and effects on cellular metabolism, it may become the preferred choice for those seeking to optimise their health and longevity.
The future of NAD+ supplementation is here.
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