
NMN vs NMNH Differences, Benefits & Risks
NAD+ precursors aren’t created equal. While NMN has established itself as a cornerstone of NAD+ supplementation, its reduced form NMNH has emerged as a potential challenger—promising faster absorption and higher NAD+ increases in preliminary research.
These two molecules take distinct biochemical paths to boost your NAD+ levels. Understanding their differences matters not just for scientific accuracy, but for making informed decisions about your health optimization strategy.
Key Takeaways:
- NMN offers a well-researched path to NAD+ enhancement, supported by extensive human trials and a documented safety profile.
- NMNH may provide faster NAD+ increases by bypassing certain enzymatic steps, though human studies are still pending.
- Both compounds aim to restore declining NAD+ levels, but they differ in stability, absorption mechanisms, and current scientific validation.
- Molecular structure sets them apart—NMNH carries an extra hydrogen molecule that alters its biological processing.
What’s the Difference Between NMN and NMNH?
NMN and NMNH take different paths to reach the same destination: higher NAD+ levels in your body. Let’s look at what sets these two compounds apart and why these differences matter for your health.

Molecular Structure
NMN (nicotinamide mononucleotide) is a direct precursor to NAD+. It consists of a nicotinamide moiety attached to ribose and a phosphate group, forming a nucleotide that the body can use to synthesize NAD+1. Meanwhile, NMNH (dihydronicotinamide mononucleotide) is the reduced form of NMN, carrying an extra hydrogen on the nicotinamide ring.2
This additional hydrogen changes certain properties, which can lead to more robust or faster NAD+ increases in some studies. However, contrary to earlier assumptions that NMNH might be “more stable” in the digestive tract, research indicates NMNH is actually less stable than NMN at neutral pH.3
Metabolic Pathways
NMN can become NAD+ through two major routes. First, the salvage pathway, where nicotinamide (NAM) is converted into NMN by NAMPT and then NMN is turned into NAD+ by NMNAT4. Second, the de novo pathway generating NAD+ from tryptophan or niacin produces NaMN and other intermediates rather than directly synthesizing NMN from scratch5. Most NMN used in cells arises from recycling NAM, making the salvage pathway the predominant and more energy-efficient route.
NMNH appears to follow a simpler, faster route. It bypasses enzymes such as NAMPT and NRK, continuing instead through NMNAT-related steps that can directly lead to NAD+ and NADH. This streamlined path may underlie reports of faster or higher NAD+ increases, as fewer conversion steps are required to boost intracellular NAD+ and NADH levels.6
Absorption and Bioavailability
One of the key factors in assessing the effectiveness of a supplement is its absorption and bioavailability. NMN has been shown to be absorbed through the gut7 and into the bloodstream, but its bioavailability can be influenced by various factors such as gut health, digestive enzymes, and the presence of other nutrients. While some research suggests that NMN may be degraded in the gut before absorption, recent studies have demonstrated that orally administered NMN can lead to increased NAD+ levels in various tissues, indicating successful absorption and utilization8.
Meanwhile, NMNH has demonstrated a higher potency in elevating NAD⁺ levels in vitro and in animal models, potentially through bypassing certain rate-limiting steps that NMN must undergo9. However, there are currently no published human clinical trials investigating NMNH. Since the enhanced effects observed in preclinical studies have not yet been confirmed in humans, it remains speculative whether NMNH will provide more rapid or extensive NAD+ boosts in real-world use. Until more human data become available, NMNH’s practical advantages over NMN should be interpreted with caution.
Research Status
While NMN has been well-researched over the past few years, NMNH is still in the early stages of study. We know NMN boosts NAD+ levels, supports mitochondrial function, and benefits overall health, but there’s not enough research on NMNH yet to fully grasp its potential.
NMN has been widely studied and has shown promising results in various areas of health, including anti-aging, metabolism, cardiovascular health, and cognitive function. Studies on animals and humans alike have demonstrated NMN’s ability to increase NAD+ levels and support mitochondrial health.10
Benefits of NMN and NMNH Compared

NMN and NAD+ have become household names in the world of cellular health and longevity. While these molecules have revolutionized how we approach energy production and aging at the cellular level, breakthrough research on NMNH is pushing the boundaries even further.
As we’ve seen, NMN and its reduced form, NMNH, are both NAD+ precursors with potential health benefits. However, early research points to NMNH being a more potent enhancer of NAD+ levels compared to NMN.
NMN Benefits
- NAD+ Restoration: Clinical studies show NMN can increase NAD+ levels, which decline with age, by about 40% within 30 days11. NMN’s ability to boost NAD+ has been shown to offset age-related diseases and improve vascular function, cognitive performance, and oocyte quality in aged models.12
- Gut Health: Long-term NMN treatment can modulate gut microbiota, increasing beneficial bacteria and reducing harmful ones, which may enhance intestinal barrier function13.
- Heart Health: NMN supplementation has been shown to decrease oxidative stress in heart tissue, lower inflammation in the cardiovascular system, and protect against DNA damage in heart cells14.
- Anti-Aging Effects: NMN supplementation has been linked to anti-aging effects15, including improved vascular function and reduced oxidative stress, through mechanisms involving sirtuin activation.
NMNH Benefits
- Potentially Superior NAD+ Enhancement: NMNH may increase NAD+ levels16 more effectively and rapidly than NMN or NR, through a different metabolic pathway.
- Metabolic Effects: NMNH suppresses glycolysis and the TCA cycle, and induces cell cycle arrest, which may have implications for cell growth regulation17.
- Tissue Protection: NMNH has shown potential in reducing damage and accelerating repair in renal cells under stress conditions18.
While both NMN and NMNH are beneficial as NAD+ precursors, early NMNH research suggests it may be more efficient in raising NAD+ levels and has unique metabolic effects that may offer additional therapeutic benefits. NMN, however, has broader documented benefits in age-related health improvements and gut health. Further research is needed to fully understand the distinct and overlapping benefits of these compounds.
Potential Risks of NMNH and NMN

NMN has been studied extensively in both animal and human trials, and so far, it has shown a strong safety profile19. Most users tolerate NMN well, even at higher doses20. Some people, however, report mild side effects that are generally rare and short-lived, such as:
- Temporary flushing or warmth in the skin
- Skin problems like itching and sweating
- Mild to moderate headaches
- Dizziness
- Fatigue and lethargy
- Sleep disturbances
- Mild gastrointestinal issues
NMNH is a newer compound, and research into its safety is still in the early stages. While preliminary studies haven’t flagged adverse effects, the lack of data means the potential side effects remain uncertain. The structural differences between NMN and NMNH could lead to unique interactions in the body, but until more human trials are conducted, we don’t have enough information to draw firm conclusions.
NMN vs NMNH: Which is Right For You?

NMN stands as the gold standard for NAD+ enhancement. Its extensive research background and established safety profile make it the clear choice for those seeking evidence-based supplementation.
NMNH represents the cutting edge—promising but unproven. While preliminary data suggest potential advantages in NAD+ biosynthesis, the limited research makes it better suited for those comfortable with scientific uncertainty.
Most healthcare professionals align with the data: NMN’s documented safety and efficacy outweigh NMNH’s theoretical benefits.
For optimal results, consider our clinically-validated NAD powder supplement Vitality NAD+ Booster—a patent-pending formula combining NMN with synergistic compounds that maximize cellular energy production.
If you prefer simplicity, Pure NMN offers >99.5% purity at a more accessible price point. Both options deliver measurable NAD+ increases, verified through our Intracellular NAD® Test.
Reference Sources:
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10240123/ ↩︎
- https://pubmed.ncbi.nlm.nih.gov/33793246/ ↩︎
- https://www.biorxiv.org/content/10.1101/2020.11.03.366427v2.full ↩︎
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11205942/ ↩︎
- https://www.nature.com/articles/s41392-020-00311-7 ↩︎
- https://faseb.onlinelibrary.wiley.com/doi/10.1096/fj.202001826R ↩︎
- https://www.mdpi.com/2218-1989/14/6/341 ↩︎
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7238909/ ↩︎
- https://researchinformation.amsterdamumc.org/en/publications/reduced-nicotinamide-mononucleotide-is-a-new-and-potent-nad-precu ↩︎
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6565489/ ↩︎
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7238909/ ↩︎
- https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2020.00246/full ↩︎
- https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2021.714604/full ↩︎
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11394709/ ↩︎
- https://link.springer.com/article/10.1007/s11357-019-00095-x ↩︎
- https://pubs.acs.org/doi/10.1021/acs.jproteome.0c01037 ↩︎
- https://pubs.acs.org/doi/10.1021/acs.jproteome.0c01037 ↩︎
- https://faseb.onlinelibrary.wiley.com/doi/10.1096/fj.202001826R ↩︎
- https://www.nature.com/articles/s41514-022-00084-z ↩︎
- https://pubmed.ncbi.nlm.nih.gov/36482258/ ↩︎
