NAD+ vs 5-Amino-1MQ
Nicotinamide adenine dinucleotide is a redox cofactor and enzyme substrate whose tissue levels fall with age in preclinical models, and because NAD+ itself is poorly absorbed orally, almost all human work has used the precursors nicotinamide riboside and nicotinamide mononucleotide. 5-Amino-1MQ is a small-molecule inhibitor of nicotinamide N-methyltransferase, the enzyme that methylates nicotinamide and so consumes S-adenosylmethionine while diverting nicotinamide away from NAD+ salvage. Unlike most pairs in this library the two are mechanistically linked rather than merely marketed together: raising NAD+ by supplying more precursor and raising NAD+ by blocking the enzyme that degrades one are two routes to the same pool. That link is documented in the literature, and a 2024 cardiac study administered an NAD+ precursor and inhibited NNMT within the same models. What has never been done is a controlled comparison of the two strategies in humans, because 5-Amino-1MQ has never been given to a person in a published trial.
They have been compared directly.
The two strategies have been engaged within single experiments, though not as a clinical comparison. Zhang and colleagues reported in The EMBO Journal in 2024 that impaired autophagic flux reduced NAD+ availability in cardiomyocytes through induction of NNMT, and that administering nicotinamide mononucleotide or inhibiting NNMT activity in autophagy-deficient hearts and cardiomyocytes both restored NAD+ levels and ameliorated cardiac and mitochondrial dysfunction. That is the closest thing to a head-to-head result in the record: two ways of raising NAD+ tested in one model with a shared endpoint. Beyond it, the connection is mechanistic rather than comparative. Rodent studies of NNMT inhibitors report rising tissue NAD+ as the readout of target engagement, and NAD+ reviews list NNMT inhibition alongside vitamin B3 precursors as a drug-based route to raising the same pool. No study has compared an NNMT inhibitor against nicotinamide riboside or nicotinamide mononucleotide in humans on any endpoint.
The 14 studies that tested both
- 01Animal in vivo2024
Control of NAD+ homeostasis by autophagic flux modulates mitochondrial and cardiac function
Zhang Q, Li Z, Li Q, et al. · The EMBO Journal · autophagy-deficient mouse hearts and isolated cardiomyocytes, with administration of the NAD+ precursor nicotinamide mononucleotide and, separately, inhibition of NNMT activity
Impaired autophagic flux reduced NAD+ availability in cardiomyocytes, and the deficiency was attributed to induction of NNMT, which methylates the NAD+ precursor nicotinamide. Administration of nicotinamide mononucleotide and inhibition of NNMT activity each restored NAD+ levels and ameliorated cardiac and mitochondrial dysfunction in the same models. The authors traced the induction of NNMT to accumulation of SQSTM1 activating NF-kappaB signalling.
- 02Animal in vivo2018
Selective and membrane-permeable small molecule inhibitors of nicotinamide N-methyltransferase reverse high fat diet-induced obesity in mice
Neelakantan H, Vance V, Wetzel MD, et al. · Biochemical Pharmacology · diet-induced obese mice dosed systemically with the quinolinium NNMT inhibitor 5-amino-1MQ
Systemic administration of the selective, membrane-permeable NNMT inhibitor reduced body weight and adiposity without reducing food intake. Adipose NAD+ rose and lipogenic gene expression was suppressed, so tissue NAD+ served as the readout of target engagement.
- 03Animal in vivo2019
Small molecule nicotinamide N-methyltransferase inhibitor activates senescent muscle stem cells and improves regenerative capacity of aged skeletal muscle
Neelakantan H, Brightwell CR, Graber TG, et al. · Biochemical Pharmacology · aged mouse skeletal muscle and isolated muscle stem cells treated with a small-molecule NNMT inhibitor
NNMT inhibition activated senescent muscle stem cells and improved regenerative capacity in aged skeletal muscle, with contractile force recovery after injury increasing by approximately 70% relative to control. The work framed the effect through the enzyme's control of nicotinamide availability for NAD+ salvage.
- 04Animal in vivo2024
Nicotinamide N-methyltransferase inhibition mimics and boosts exercise-mediated improvements in muscle function in aged mice
Dimet-Wiley AL, Latham CM, Brightwell CR, et al. · Scientific Reports · aged sedentary and exercised mice treated with an NNMT inhibitor
NNMT inhibition produced grip strength gains of roughly 40% in aged sedentary mice, and the benefits were additive when the inhibitor was combined with exercise training. The rationale set out in the report was preservation of nicotinamide for NAD+ salvage in skeletal muscle.
- 05Animal in vivo2024
Identification of nicotinamide N-methyltransferase as a promising therapeutic target for sarcopenia
Liang R, Xu Y, Bai H, et al. · Aging Cell · aged mice with age-related muscle loss treated with NNMT inhibition
NNMT inhibition improved grip strength and muscle mass in aged mice. The effects were associated with increased NAD+ levels and AMPK activation in skeletal muscle, linking the enzyme directly to the NAD+ pool in the tissue studied.
- 06Animal in vivo2024
NAD+ metabolism enzyme NNMT in cancer-associated fibroblasts drives tumor progression and resistance to immunotherapy by modulating macrophages in urothelial bladder cancer
Yang M, Wang B, Hou W, et al. · Journal for ImmunoTherapy of Cancer · human bladder cancer specimens with single-cell transcriptomics and immunostaining, plus mouse tumour models treated with 5-amino-1-methylquinolinium iodide
Elevated expression of NNMT, described by the authors as an NAD+ metabolism enzyme, in cancer-associated fibroblasts was associated with non-response to PD-L1 blockade and unfavourable prognosis in two independent cohorts. Targeting NNMT with 5-amino-1-methylquinolinium iodide significantly reduced tumour growth and enhanced the apoptotic effects of an anti-PD-L1 antibody in mouse models.
- 07In vitro2025
Mechanism and kinetics of turnover inhibitors of nicotinamide N-methyl transferase in vitro and in vivo
Akerud T, et al. · Journal of Biological Chemistry · enzyme kinetics and mechanistic studies in vitro, with confirmatory rat pharmacology
Certain NNMT inhibitors were reported to be substrates that undergo enzymatic turnover, generating methylated metabolites more potent than the parent compound, and rat experiments indicated the mechanism operates in vivo. The work characterised how these inhibitors interact with the same methylation reaction that consumes nicotinamide.
- 08Animal in vivo2025
Nicotinamide N-methyltransferase inhibition improves limb function in experimental peripheral artery disease
Dong G, et al. · Physiological Reports · mouse hindlimb ischaemia model of peripheral artery disease treated with an NNMT inhibitor
NNMT inhibitor treatment enhanced muscle strength and treadmill performance in mice with hindlimb ischaemia, and the functional gains occurred independently of perfusion recovery. The indication overlaps with the one setting in which an NAD+ precursor has improved walking distance in a randomised human trial.
- 09Review2023
Nicotinamide N-methyltransferase and liver diseases
Liang G, Li Y, Lin Y, et al. · Genes & Diseases · narrative review of NNMT in hepatic metabolism and liver disease
The review set out how NNMT methylates nicotinamide using S-adenosylmethionine, directly linking the methylation balance with cellular NAD+ content, and described the enzyme as acting on the methylation balance, on NAD+ metabolism, or on both depending on tissue and pathological setting. It did not report new experimental data.
- 10Review2024
Biological Functions and Therapeutic Potential of NAD+ Metabolism in Gynecological Cancers
Myong S, Nguyen AQ, Challa S · Cancers · narrative review of NAD+ biosynthesis, consumption and therapeutic targeting in gynaecological cancers
The review described how NAD+ levels are maintained by a balance between biosynthesis through the Preiss-Handler, de novo and salvage pathways and consumption by ADP-ribosyl transferases, sirtuins and CD38. It covered efforts to target the enzymes controlling NAD+ homeostasis, NNMT among them, rather than reporting new experiments.
- 11Review2025
The role of NAD+ metabolism and its modulation of mitochondria in aging and disease
Yusri K, Jose S, Vermeulen KS, Tan TCM, Sorrentino V · npj Metabolic Health and Disease · narrative review of NAD+ metabolism, compound-based modulation and mitochondrial homeostasis in ageing
The review described raising cellular NAD+ through vitamin B3 family precursors or through drug-based interventions as a broadly used strategy for restoring mitochondrial and organismal homeostasis, and summarised results of NAD+-boosting therapeutics in clinical trials. It placed enzyme-directed approaches and precursor supplementation within a single framework.
- 12Review2025
Nicotinamide N-Methyltransferase (NNMT) and Liver Cancer: From Metabolic Networks to Therapeutic Targets
Lai SY, Zhu XJ, Sun WD, et al. · Biomolecules · narrative review of NNMT in hepatocellular carcinoma, spanning metabolic networks and candidate interventions
The review described NNMT as a metabolic enzyme central to the NAD+ and methionine cycles and attributed part of its role in hepatocellular carcinoma to driving NAD+ depletion and homocysteine accumulation. It evaluated NNMT inhibitors, RNA-based therapies and non-pharmacological strategies as candidate interventions without reporting new data.
- 13Review2024
Nicotinamide N-methyltransferase (NNMT): a novel therapeutic target for metabolic syndrome
Sun WD, Zhu XJ, Li JJ, et al. · Frontiers in Pharmacology · narrative review of NNMT in obesity, insulin resistance, dyslipidaemia and hepatic steatosis
The review linked elevated NNMT expression to features of metabolic syndrome across rodent and human tissue studies and summarised knockdown and inhibitor data reporting enhanced energy expenditure and insulin sensitivity in rodent models. Its account of the mechanism runs through nicotinamide handling and NAD+ availability.
- 14Review2025
Nicotinamide N-Methyltransferase in Cardiovascular Diseases: Metabolic Regulator and Emerging Therapeutic Target
Jawaria, et al. · Biomolecules · narrative review of NNMT in cardiovascular pathophysiology
The review described NNMT's contribution to cardiovascular disease through NAD+ depletion and homocysteine elevation, and catalogued preclinical evidence for benefit from NNMT inhibition. It noted the absence of clinical confirmation for that approach.
Side by side.
| NAD+ | 5-Amino-1MQ | |
|---|---|---|
| Evidence maturity | Early clinical | Preclinical only |
| Studies cited here | 15 | 15 |
| Published 2023 or later | 11 | 8 |
| Newest paper | 2026 | 2026 |
| Molecular class and origin | An endogenous dinucleotide cofactor present in every cell. Because it is poorly absorbed orally, the compounds actually studied in humans are its precursors, principally nicotinamide riboside and nicotinamide mononucleotide. | A synthetic cell-permeable quinolinium small molecule with no endogenous counterpart, developed as a selective inhibitor of a single enzyme. |
| Mechanism as described in the literature | Supplying substrate. NAD+ acts as a redox cofactor and as substrate for sirtuins, PARPs and CD38, and precursor supplementation raises the circulating pool by feeding the salvage pathway. | Removing a drain on the same pool. NNMT methylates nicotinamide using S-adenosylmethionine, consuming the methyl donor and diverting nicotinamide away from NAD+ salvage, so inhibiting it is reported to raise tissue NAD+ while also altering methylation potential and polyamine flux. |
| Size of the evidence base | Fifteen studies in this library, most of them randomised controlled trials in humans, together with systematic reviews and meta-analyses. | Fifteen studies in this library, none of them human. The set is rodent in vivo work, enzyme kinetics and reviews of the target. |
| Best-characterised finding | That oral precursors reliably raise circulating NAD+. Randomised trials consistently show two- to threefold increases with nicotinamide riboside or nicotinamide mononucleotide, sustained over weeks to months and well tolerated. | Reversal of diet-induced obesity in mice without reduced food intake, alongside grip strength and muscle regeneration gains in aged mice, in each case with rising tissue NAD+ reported as the marker of target engagement. |
| Human data | Substantial and, on functional endpoints, largely disappointing. Trials have reported improved walking distance in peripheral artery disease, improved muscle insulin sensitivity in prediabetic women and better sleep quality in older adults, while meta-analyses of muscle, glucose and lipid outcomes have been null and a long-COVID trial found no cognitive or fatigue benefit despite a sustained rise in NAD+. | None. No human clinical trial has been published, and human pharmacokinetics, oral bioavailability, safety and target engagement are uncharacterised. |
| Evidence maturity | Early clinical. The pharmacokinetic question is settled and the tolerability record is reasonable to about six months, but no trial has shown durable improvement in muscle mass, cognition, glycaemic control or blood pressure. | Preclinical only. A 2026 review in Trends in Pharmacological Sciences framed clinical translation of NNMT inhibitors as an emerging rather than established prospect. |
| Recency of primary research | Active and clinical, with 2026 publications including a three-arm comparison of NAD+ boosters in healthy participants, a Friedreich's ataxia trial in The Lancet Neurology, a mild cognitive impairment pilot and a safety meta-analysis. | Active but preclinical, with 2025 and 2026 output covering inhibitor turnover kinetics, a peripheral artery disease model and translational reviews. |
| Safety signals reported | Generally reassuring within the durations studied. A meta-analysis of fifteen randomised trials found no increase in overall, serious or system-specific adverse events and no elevation of liver enzymes, though no human data address safety beyond about six months. | No human safety data. Open preclinical questions include the long-term consequences of sustained NNMT inhibition for methylation potential, polyamine metabolism and tumour biology, the last of which matters because much of the enzyme's literature concerns cancer. |
And what it does not.
This is one of the few pairs in this library with a genuine mechanistic connection rather than a marketing one, and one experiment has engaged both routes at once: a 2024 cardiac study found that supplying nicotinamide mononucleotide and inhibiting NNMT each restored NAD+ and improved mitochondrial and cardiac function in autophagy-deficient hearts. That result supports the idea that the two strategies converge on the same pool. It does not establish that they are equivalent, that either works in humans for the purposes they are sold for, or that one is preferable. The human NAD+ literature is the more instructive caution here: precursors reliably raise circulating NAD+ two- to threefold and are well tolerated, yet meta-analyses of muscle, glucose and lipid outcomes are null, which shows that raising NAD+ and improving a clinical endpoint are separate questions. 5-Amino-1MQ has never reached that test, because no human has received it in a published trial.
Common questions.
- Has any study raised NAD+ by both routes in the same experiment?
Yes, once. A 2024 report in The EMBO Journal found that impaired autophagic flux lowered NAD+ in cardiomyocytes by inducing NNMT, and that administering nicotinamide mononucleotide or inhibiting NNMT activity each restored NAD+ levels and improved cardiac and mitochondrial dysfunction in autophagy-deficient hearts and cells. That is an animal and cell study addressing a specific disease mechanism, not a comparison of the two approaches as interventions, and no equivalent experiment has been reported in humans.
- If NNMT inhibition raises NAD+, why is it not simply a stronger version of a precursor?
Because the enzyme does more than degrade nicotinamide. NNMT consumes S-adenosylmethionine, the universal methyl donor, so inhibiting it alters methylation potential as well as NAD+ availability, and the founding rodent work also attributed metabolic effects to increased adipose polyamine flux. Reviews describe the enzyme as acting on the methylation balance, on NAD+ metabolism, or on both depending on the tissue. Precursor supplementation feeds the salvage pathway without those additional consequences.
- What did the human NAD+ trials fail to show?
They have consistently failed to translate a measurable biochemical change into a clinical one. A meta-analysis of nicotinamide mononucleotide and nicotinamide riboside found no significant effect on skeletal muscle index, handgrip strength, gait speed or the chair-stand test, and a separate safety meta-analysis found no effect on body weight, fasting glucose, HbA1c, lipids or systolic blood pressure. A long-COVID trial raised blood NAD+ two- to threefold for twenty weeks with no between-group difference in cognition, fatigue, sleep, anxiety or depression.
- Does the peripheral artery disease work overlap between the two?
The indication does, though not the design. A randomised, double-blind, placebo-controlled trial of nicotinamide riboside in adults with lower-extremity peripheral artery disease reported an improvement in six-minute walk distance versus placebo, with a larger difference among the more adherent participants. Separately, a 2025 mouse hindlimb ischaemia study found that an NNMT inhibitor enhanced muscle strength and treadmill performance independently of perfusion recovery. One is a human trial and one is a rodent model, and they were not compared.
- Why does so much NNMT research concern cancer rather than metabolism?
Because the enzyme was identified as a metabolic regulator in tumour stroma as well as in adipose tissue. Reviews of gynaecological cancer, hepatocellular carcinoma and cardiovascular disease all describe NNMT through NAD+ depletion and altered methylation, and a 2024 bladder cancer study used 5-amino-1-methylquinolinium iodide to reduce tumour growth in mice. That literature is relevant to the safety question, since the long-term consequences of sustained NNMT inhibition for tumour biology remain unresolved.
For research purposes only. Not for human consumption, diagnosis, treatment, or prevention of any condition. Nothing on this page is medical advice, and no comparison here should be read as a recommendation of either compound.