NMN vs. NMNH: What's The Difference?

NMN (Nicotinamide Mononucleotide) and NMNH (Nicotinamide Mononucleotide Hydrogen) are two forms — like two sides of the same coin — of a nicotinamide adenine dinucleotide (NAD+) precursor.

The goal of taking NMN supplements is to increase NAD+ levels in the body, which we need to support virtually all cellular functions that contribute to healthier aging.

So, if the goal is to increase NAD, why don't we take NAD supplements?

The issue is that NAD supplements aren't as readily absorbed as precursors, so NMN, and possibly its reduced form NMNH, makes for a more efficient way to increase NAD.

When we talk about "reduced forms," we're referring to molecules that have undergone a chemical change by gaining electrons. This change can affect how the molecule behaves in the body. 

NMNH is the reduced form of NMN, meaning it has gained extra electrons. NMN and NMNH can convert back and forth in the body depending on cellular needs.

NMN vs. NMNH Comparison

NMN and NMNH are nucleotide precursors to NAD+. While NMNH absorbs faster, it’s unstable and converts mainly to NADH, which some people suggest disrupts the NAD+ to NADH balance needed for benefits. NMN is more stable, better researched, and the preferred choice for raising NAD+ levels effectively.

NMN (Nicotinamide Mononucleotide)

NMN is directly converted into NAD+ within cells, helping to increase the NAD+ to NADH ratio, which researchers agree is the key to its benefits [1].

Compared to NMNH, there's much more research on the benefits of NMN supplementation as it's a much more stable form and has shown promising results for supporting healthy aging long term.

NMN supplements might be harder to find on the American market because its status as a dietary supplement is being reviewed by the FDA after a company expressed interest in investigating it as a drug.

Since 2022, NMN has existed in a regulatory limbo, preventing it from being sold as a dietary supplement in the U.S. However, NMN remains widely available in other regions, including Asia and Europe, and can still be purchased online in the United States from select retailers.

NMNH (Reduced Nicotinamide Mononucleotide)

NMNH has been observed in early studies to absorb into the cells much more quickly compared to other NAD+ precursors like NMN and NR (nicotinamide riboside) [2]. Still, NMNH is known to be finicky to work with because it's so unstable.

NMNH quickly converts into NADH — the reduced form of NAD. This doesn't necessarily mean it increases NAD+ in humans, but it was observed in mammalian cells and mice [2].

We've sifted through the internet to find that some people are claiming NMNH works better than NMN at increasing NMN. 

Still, there are only two animal studies on NMNH supplementation, and no human clinical trials have been published yet, making it difficult to determine the best dosage and the safety profile of NMNH supplements in the long term [2].

NMNH may affect cellular metabolism (how cells make and use energy). Some research suggests that NMNH slows down two important processes: glycolysis (how cells break down sugar for energy) and the TCA cycle (how cells turn food into energy) [3]. This might help treat certain health conditions, but more research is needed.

Unlike NMN, NMNH hasn’t been reviewed by the FDA for its potential as a drug, so it can still be sold as a supplement. However, NMNH isn’t very popular because it’s less stable, doesn’t have as much research behind it, and isn’t as well-known. You might find it harder to buy than NMN, but it’s still available.

NMN vs. NMNH: Which Works Best for Increasing NAD?

NMN is the clear choice.

NMNH’s faster absorption may sound appealing, but its instability and tendency to convert into NADH could diminish its effectiveness for raising NAD+ levels. The current research overwhelmingly supports NMN as the better option because it increases NAD+ levels and maintains the optimal NAD+ to NADH ratio that benefits the body.

What is NMNH from NMN?

NMNH is the reduced form of NMN, meaning it’s a slightly altered version with extra electrons.

The point of gaining extra electrons is to store or transfer energy in chemical reactions. Molecules like NMNH act as carriers in the body’s energy processes, helping to pass electrons along to power cellular functions.

NMNH gets these electrons from other molecules during reactions like when enzymes in the body help transfer electrons to or from NAD+ and NADH as part of the cell’s energy cycle.

This electron transfer is like passing a baton in a relay race — it’s part of how cells manage energy and repair.

In the body, NMN and NMNH can switch back and forth depending on the cells' needs. Reduced forms, like NMNH, are created when molecules gain electrons, which can change how they work or are used.

Safety and Side Effects of NMN and NMNH

NMNH is generally considered safe, but we lack long-term studies in humans to understand its full safety profile for continued use. Like all supplements, people can have negative reactions, and some common NMNH side effects include nausea, headaches, and drowsiness, which are mild and temporary.

NMN is also safe and tolerated well in healthy individuals but may have the same side effects when taken in large doses.

NMNH vs. NMN Supplements

If I had to choose between NMNH and NMN supplements for supporting my healthy aging journey, I'd stick with NMN.

NMN is known to be more shelf-stable, well-researched, and widely recognized for its effectiveness in supporting NAD+ levels in the body in humans.

NMNH may absorb faster, but its instability and tendency to convert primarily into NADH make it possibly less effective for boosting the NAD+ to NADH ratio, which is an important part of maintaining cellular health.

On the other hand, NMN has shown consistent results in human studies and is trusted for its role in promoting energy, cellular repair, and healthy aging.

Resources:

1. Katayoshi, T., Uehata, S., Nakashima, N., Nakajo, T., Kitajima, N., Kageyama, M., & Tsuji-Naito, K. (2023). Nicotinamide adenine dinucleotide metabolism and arterial stiffness after long-term nicotinamide mononucleotide supplementation: a randomized, double-blind, placebo-controlled trial. Scientific Reports, 13(1), 2786.

2. Zapata-Pérez, R., Tammaro, A., Schomakers, B. V., Scantlebery, A. M. L., Denis, S., Elfrink, H. L., ... & McIntyre, R. L. Reduced nicotinamide mononucleotide is a new and potent NAD+ precursor in mammalian cells and mice., 2021, 35, p. e21456. DOI: https://doi. org/10.1096/fj, 202001826.

3. Liu, Y., Luo, C., Li, T., Zhang, W., Zong, Z., Liu, X., & Deng, H. (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.