Head to head
NMN against NMNH
NMN and its reduced form, which raises NAD in cells and mouse tissue faster and higher. In the same experiments NMNH inhibited glycolysis and the TCA cycle, induced cell cycle arrest and suppressed cell growth in vitro, and no human has been given it in a published trial.
Column A
NMNNicotinamide Mononucleotide
A direct NAD+ precursor studied for metabolic and physical-function benefits in aging, with early human trials and a contested regulatory status in the US.
Column B
NMNHReduced nicotinamide mononucleotide, dihydronicotinamide mononucleotide
Raises NAD in cells and mouse tissue faster and higher than NMN, through a pathway that needs neither NRK nor NAMPT. In the same experiments it inhibited glycolysis and the TCA cycle, induced cell cycle arrest and suppressed cell growth in vitro, and no human has been given it in a published trial.
Side by side, on the facts we can check
| Attribute | NMN | NMNH |
|---|---|---|
| Category | Longevity | Longevity |
| FDA status | Not an approved drug; US supplement status contested | Not an approved drug and not an established dietary ingredient in the United States. Unlike NMN, which has a documented and contested regulatory history, NMNH has no FDA determination of any kind because it has not been the subject of one. |
| Half-life | Short | No human pharmacokinetic study has been published, so no half-life in people can be stated. In mice the whole-blood NAD rise was described as rapid and sustained, which is a downstream metabolite measurement rather than clearance of the compound. |
| Molecular weight | 334.2 Da | The reduced, dihydro form of nicotinamide mononucleotide, which is 334.2 Da in its oxidised form. |
| Mechanism | Converts to NAD+ through the salvage pathway, aiming to restore NAD+ levels that decline with age. | NMNH is adenylylated directly by NMNAT enzymes to NADH, which then enters the NAD pool. This bypasses NAMPT, the rate-limiting salvage enzyme that nicotinamide depends on, and also bypasses the NRK kinases that NR depends on, which is why it outperforms both in cells. It is also the downstream metabolite of NRH, so the two reduced precursors converge. Because the molecule enters as the reduced dinucleotide, it raises cellular NADH as well as NAD and shifts the redox ratio, which is the likely explanation for the observed inhibition of glycolysis and the TCA cycle, both of which are regulated by NAD to NADH ratio. |
| Human studies cited | 2 | 1 |
| Legal status, US | Not approved; FDA excluded it from the supplement definition (2022) | Not approved; research use only |
Frequently asked questions
What is the difference between NMN and NMNH?
NMN: A direct NAD+ precursor studied for metabolic and physical-function benefits in aging, with early human trials and a contested regulatory status in the US. NMNH: Raises NAD in cells and mouse tissue faster and higher than NMN, through a pathway that needs neither NRK nor NAMPT. In the same experiments it inhibited glycolysis and the TCA cycle, induced cell cycle arrest and suppressed cell growth in vitro, and no human has been given it in a published trial.
Which has stronger research evidence, NMN or NMNH?
This database does not grade compounds. It counts what was run in people: 2 of the 3 studies cited on the NMN profile were human work, against 1 of 4 for NMNH. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are NMN and NMNH FDA-approved?
NMN: Not an approved drug; US supplement status contested. NMNH: Not an approved drug and not an established dietary ingredient in the United States. Unlike NMN, which has a documented and contested regulatory history, NMNH has no FDA determination of any kind because it has not been the subject of one..
Related posts
Blog articles that cover NMN or NMNH, newest first.
- Longevity / Sep 8, 2026 / 9 minThe Rapamycin Dosing Debate: What PEARL Tested, the Bioavailability Problem, and What Is Unproven
- Metabolic / Sep 8, 2026 / 7 minSLU-PP-332 and 5-Amino-1MQ: Two 'Peptides' That Are Not Peptides, and What the Mouse Data Actually Show
- Longevity / Sep 8, 2026 / 8 minNMN vs NR vs NAD+: The 2026 Head-to-Head Human Trials, and Who Funded the Comparisons
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.