Difference Between NMN And NMNH: NMN vs NMNH | HealthspanX

NMN remains the evidence-based choice for most adults today because it has human data and a documented safety profile. NMNH (the reduced form of NMN) looks metabolically powerful in cells and mice but it still lacks human trials. Until those arrive, choose NMN for confidence, and treat NMNH as a research-grade option.

If you are looking to boost NAD+ levels, you might have seen a new kid on the block: NMNH. It’s a reduced form of the beloved NMN, and people seem to claim that it works better. Does it really though? We don’t know - because there aren’t any human studies comparing NMN and NMNH. However, let’s explore the differences between these two compounds and see what fits your needs better.

What's The Difference Between NMN And NMNH?

NMN is the oxidized form of the nucleotide that cells convert to NAD+ via the classical salvage pathway. NMNH is the reduced analog (dihydronicotinamide mononucleotide). Chemically, NMNH carries one extra hydrogen on the nicotinamide ring.

Other NAD+ precursors, such as nicotinamide riboside, are also being studied and compared in research for their effectiveness and health benefits.

NMNH As A Dietary Supplement?

Studies show that NMNH may be able to boost NAD+ more than NMN. Preliminary research suggests NMNH may be absorbed faster or be more effective than NMN, but these findings are not yet fully confirmed. And its efficacy in humans is untested.

A 2021 paper demonstrated that NMNH treatment in animal models increased NAD+ levels higher than NMN in mammalian cells and in mice. However, it was also found to be suppressing cell growth and metabolism, and nmnh inhibited glycolysis in these studies.
Similarly, another paper found that NMNH can increase NAD+ levels faster and higher than NMN and NR. And that it was bioavailable to most tissues in the body.

Current research is still limited and ongoing, with most findings based on animal studies and animal models.

Chemical Structure And Function Of NMN And NMNH

NMN (nicotinamide mononucleotide) and NMNH (nicotinamide mononucleotide hydrogen) are both naturally occurring molecules. They serve as essential precursors in the production of nicotinamide adenine dinucleotide (NAD+), a coenzyme that fuels countless cellular processes and supports optimal energy metabolism. The key difference between these two compounds lies in their chemical structure: NMNH is the reduced form of NMN, meaning it contains an extra hydrogen atom on the nicotinamide ring. This subtle change has a significant impact on how each molecule interacts with the enzymes responsible for NAD+ synthesis.

NMN vs NMNH

In the body, NMN is converted into NAD+ through the action of the enzyme nicotinamide mononucleotide adenylyltransferase (NMNAT), playing a critical role in maintaining cellular health, DNA repair, and supporting energy production. NMNH, thanks to its reduced form, can be directly utilized in the NAD+ biosynthesis pathway, potentially offering a more efficient route to boosting NAD+ levels. This difference in metabolic pathways may influence how effectively each compound supports cellular functions such as DNA repair, mitochondrial function, and overall cellular metabolism.

Understanding the chemical structure and function of both NMN and NMNH is crucial for appreciating their potential benefits in supporting cellular health, healthy aging, and metabolic health. As research continues, these differences may help explain variations in their effects on energy metabolism and other aspects of cellular function.

How NMN vs NMNH Climb To Nicotinamide Adenine Dinucleotide (NAD+)

NMN mainly becomes NAD+ via NAMPT after being produced or transported in the salvage cycle. On the other hand, NMNH can be directly used by NMNAT to form NADH. That’s because NMNH skips the NAMPT-step, and goes through a shorter pathway to NAD+. These metabolic processes are essential for cellular energy production, as they enable the conversion of NMN and NMNH into NAD+ and NADH, which are crucial for supporting energy and healthy aging.

Picture NAD+ synthesis as a multi-lane interchange. NMN uses the main highway with a couple of toll booths (NAMPT) before it reaches NMNAT, which finally merges you into NAD+ City. But unlike NMN, NMNH uses a bypass road that drops you near the city center quicker entry. Both NMN and NMNH support energy by fueling cell metabolism and the electron transport chain, which are vital for ATP production and overall metabolic health. Like NMN, NMNH may also improve mitochondrial function through its direct impact on NAD+ and NADH levels, enhancing energy metabolism and cellular vitality.

Now you might be wondering, NMNH clearly seems to be more impressive than NMN; what’s the catch? Well, there’s always a catch. A faster route is impressive, but the destination (durable, safe clinical benefit in humans) still needs human trials for NMNH. That’s where NMNH cannot outperform NMN - solid, clinical evidence from human studies. And we are going to talk about that next.

Is NMNH Safe?

NMNH has not been tested in clinical trials. Therefore, we can’t say anything about its safety. On the other hand, NMN has been extensively tested in short-term human trials.

Additionally, studies have shown that NMNH can slow down metabolism. It inhibits glycolysis and the TCA cycle, which is a major pathway for energy production in the cells. Surprisingly, it also slows cell cycle progression at higher exposure.

Therefore, in the longer run, NMNH might not be as effective as NMN. However, we will need longer trials to figure out the safety and efficacy of long-term use for either of them. Given the limited human research on NMNH, it is important to consult a healthcare professional before starting any new supplements.

What Benefits Can You Expect From NMNH

We currently do not have any human data to show benefits of NMNH. On the other hand, NMN supplementation has been shown in numerous human and animal studies to improve insulin sensitivity, support cellular repair, and promote healthier aging. NMN has also been linked to slower cognitive decline and may support brain function. Additionally, NMN can improve blood flow and support cardiovascular health.

NMNH may influence fat metabolism and brown adipose tissue activity, which are important for energy regulation and metabolic health. Both NMN and NMNH play a role in supporting energy, mitochondrial health, and optimal health by enhancing NAD+ levels and cellular repair.

Current research on NMNH suggests potential for addressing age-related decline, but more human research is needed. Meanwhile NMN has proven to be quite effective at targeting a myriad of different conditions

So, essentially, NMN has the decision-ready evidence base for people. NMNH has eye-catching lab power but no human efficacy data yet.

Bioavailability Of NMN And NMNH Supplements

NMN supplementation is found to be bioavailable to most tissues. However, we still lack data from human trials showing the same for NMNH supplements.

Bioavailability—the body’s ability to absorb and utilize a compound—is another important factor when considering NMN and NMNH. Research suggests that NMNH may have superior bioavailability compared to NMN, potentially leading to more efficient increases in NAD+ levels and greater support for cellular health. However, NMNH requires further studies, especially human trials, to fully understand its absorption, metabolism, and long-term safety.

Should You Choose NMN Or NMNH?

Currently, everyone should choose NMN over NMNH simply because of the overwhelming amount of human data that’s already available for NMN. NMNH is considered a potent form of NAD+ precursor, showing a greater ability to boost NAD+ levels in animal studies, but current research lacks extensive human data.

Both NMN and NMNH are NAD+ precursors, which play important roles in human cell metabolism and energy production. However, people should be cautious of NMNH due to the lack of clinical studies.

A clinical trial for NMNH had concluded towards the start of 2025. As of the time that we are writing this article, that trial has yet to publish its data anywhere - including non-peer-reviewed platforms. Thus, we can’t say much about NMNH’s efficacy right now.

Pick NMN if you want a well-studied, human-tolerated path to better NAD+ status with predictable day-to-day use.

Final Takeaway: Difference Between NMN and NMNH For Healthy Aging

In the fight of NMNH vs NMN, choose NMN for an evidence-first NAD+ plan right now. The safety and potential benefits of NMNH are still under investigation and require more human research to determine their effects in humans, especially on age-related diseases.

Watch NMNH closely. Early research suggests that it is a serious biochemical contender with strong preclinical momentum. But it needs human pharmacokinetics, dose-finding, and safety trials before routine use.

If you are considering adding either NMN or NMNH to your supplement routine, it is essential to consult with a healthcare provider, particularly if you have underlying health conditions or are taking other medications.

Additionally, the quality and purity of NMN and NMNH supplements can vary widely, so choosing products from reputable sources is crucial to maximize potential benefits and minimize risks. As research continues to evolve, staying informed about regulatory updates and new findings will help you make the best choices for your health and well-being.

If you are ready to add decades of health to your life, try Ultra Pure NMN™ - science-backed, rigorously third-party tested, ultra high purity NMN supplement!

References

Zapata-Pérez, R., Tammaro, A., Schomakers, B. V., et al. (2021). Reduced nicotinamide mononucleotide is a new and potent NAD+ precursor in mammalian cells and mice. The FASEB Journal, 35(4), e21456. https://doi.org/10.1096/fj.202001826R
Liu, Y., Luo, C., Li, T., et al. (2021). Reduced nicotinamide mononucleotide (NMNH) potently enhances NAD+ and suppresses glycolysis, the TCA cycle, and cell growth. Journal of Proteome Research, 20(5), 2596–2606. https://doi.org/10.1021/acs.jproteome.0c01037