5-Amino-1MQ

Mechanism of action

5-Amino-1MQ (5-amino-1-methylquinolinium) is a small-molecule quinolinium-based selective inhibitor of nicotinamide N-methyltransferase (NNMT, EC 2.1.1.1), an enzyme that catalyses the transfer of a methyl group from S-adenosyl-L-methionine (SAM) to nicotinamide, generating 1-methylnicotinamide (1-MNA) and S-adenosyl-L-homocysteine (SAH). NNMT therefore consumes two critical cellular cofactors: SAM (the principal cellular methyl donor) and nicotinamide (a precursor for NAD+ salvage biosynthesis). Pathological overexpression of NNMT — well documented in white adipose tissue of obese mice and humans, and in several cancers — produces a 'double depletion' phenotype: reduced SAM availability for methylation reactions (DNA methylation, histone methylation, phospholipid methylation, neurotransmitter synthesis) and reduced nicotinamide pool feeding the NAD+ salvage pathway. The resulting low NAD+ state impairs sirtuin function, PARP signalling, and mitochondrial bioenergetics — producing the metabolic phenotype characteristic of NNMT-overexpressing tissues. 5-Amino-1MQ binds the NNMT active site as a competitive inhibitor with selectivity over related methyltransferases. Crystal-structure work has confirmed binding in the nicotinamide-binding pocket with the methylated quinolinium nitrogen mimicking the nicotinamide N-methyl-acceptor configuration. The inhibition is competitive and reversible. In cell-culture and animal models, 5-Amino-1MQ treatment of NNMT-overexpressing adipocytes produces restoration of cellular SAM and NAD+ levels, with downstream consequences including increased fatty acid oxidation, increased mitochondrial biogenesis (through restored sirtuin-PGC-1α signalling), decreased de novo lipogenesis, and modest reductions in adipocyte size and lipid content. The principal pre-clinical evidence comes from the Brenner laboratory and others. In high-fat-diet-fed obese mice, oral 5-Amino-1MQ administration over 10-12 weeks produced modest reductions in body weight and adipose-tissue mass, increased fatty acid oxidation in skeletal muscle, improved glucose tolerance, and reduced hepatic steatosis. The effect sizes are smaller than incretin-pathway pharmacology (semaglutide, tirzepatide) but the mechanism is mechanistically distinct — addressing the cellular methyl-donor and NAD+ depletion characteristic of NNMT-overexpressing tissue rather than the appetite-and-insulin pathway addressed by incretins. Additional research interest in 5-Amino-1MQ comes from skeletal-muscle work: NNMT inhibition in aged or obese skeletal muscle restores satellite-cell function (Neelakantan et al., Biochem Pharmacol 2018, and follow-on work), which has stimulated investigation in sarcopenia, age-related muscle decline, and exercise-recovery research. The skeletal-muscle effects are mechanistically distinct from the adipose-tissue effects and may be the more pharmacologically tractable application. A mechanistically important consideration is that 5-Amino-1MQ is NOT a peptide — despite frequent grouping with metabolic research peptides in research-chemical-community contexts. The molecular weight is small (~160 Da for the cation), the structure is a methylated quinolinium ring system rather than a peptide bond polymer, and the pharmacokinetics, formulation chemistry, and regulatory framework all parallel small-molecule rather than peptide pharmacology.

Selective pharmacological NNMT inhibition with 5-Amino-1MQ in high-fat-diet obese mice produces sustained reduction in body weight, adipose-tissue mass, and hepatic steatosis with restoration of cellular SAM and NAD+ pools (Neelakantan et al., Biochem Pharmacol 2018) — establishing the first pharmacological proof-of-concept for the NNMT-as-metabolic-target hypothesis emerging from the Kraus 2014 Nature paper.

— Notable finding

Research history

5-Amino-1MQ was developed as a tool compound in the broader academic effort to characterise NNMT pharmacology, particularly through the work of Charles Brenner and collaborators at the University of Iowa and subsequent groups. The compound emerged from medicinal chemistry programmes seeking selective NNMT inhibitors — historically a challenging target because of the chemical similarity between nicotinamide substrates and inhibitors and the broad expression pattern of related methyltransferases. The seminal pre-clinical adipose-tissue work was published in 2015 (Kraus et al., Diabetes), demonstrating NNMT overexpression in white adipose tissue of obese mice and humans and the metabolic phenotype rescue by genetic NNMT knockdown. The hypothesis that pharmacological NNMT inhibition could reproduce the genetic-knockdown phenotype motivated the medicinal chemistry programmes that produced 5-Amino-1MQ and related selective inhibitors. Subsequent academic and industrial research has characterised 5-Amino-1MQ's adipose, skeletal-muscle, and cancer-research applications. Multiple academic publications across 2017-2023 have documented the metabolic effects in obesity models, the skeletal-muscle satellite-cell rescue in aged mice, and emerging cancer-research applications where NNMT is overexpressed (notably in several solid tumours including ovarian and colorectal cancers). No formal clinical-development programme for 5-Amino-1MQ has been announced publicly. The compound exists in academic and grey-market research-chemical channels without a marketing-authorisation holder pursuing human therapeutic development. This is consistent with the broader off-patent small-molecule problem affecting many academically-discovered candidates: scientific merit can be high while the commercial and regulatory pathway to human use remains blocked by the absence of sponsor interest. The compound has gained moderate visibility in research-chemical-community contexts — grouped (somewhat misleadingly) with metabolic peptides like MOTS-c and AOD-9604 — driven by interest in the NAD+ longevity research framework and the appetite for non-incretin metabolic mechanisms. Research-chemical supply is widely available at relatively low cost given the small-molecule synthesis.

Reported research-model dose ranges

The ranges below are taken from published pre-clinical literature. They do not constitute a dosing recommendation for human use.

Summarised studies

Safety profile

5-Amino-1MQ's safety dataset is limited to pre-clinical work — there are no published human clinical-trial data. The pre-clinical safety record across rodent obesity and skeletal-muscle studies has been favourable: oral doses of 50-200 mg/kg/day over 10-12 weeks produced no overt toxicity, no significant changes in routine haematology or hepatic enzymes beyond expected age-related drift, and no documented organ-specific lesions in standard histopathology. Theoretical safety considerations centre on the NNMT pathway's broader biological roles. NNMT is expressed at modest baseline levels in many tissues and contributes to methyl-donor metabolism, nicotinamide handling, and (through 1-methylnicotinamide as a signalling molecule) to vascular and inflammatory regulation. Chronic systemic NNMT inhibition could theoretically affect tissues beyond the adipose and skeletal-muscle research targets. The pre-clinical absence of overt off-target toxicity is reassuring but the pharmacological space is incompletely characterised. Methylation-dependent processes (DNA methylation, histone methylation, neurotransmitter synthesis) might theoretically be affected by chronic NNMT inhibition through SAM-pool effects. The pre-clinical work has not identified clinically significant methylation perturbations at research doses, but human chronic dosing has not been performed. Formulation safety for the iodide salt — the standard research-chemical form — should consider iodide-pool effects in chronic dosing. The iodide counter-ion is not biologically inert and chronic high-dose oral 5-Amino-1MQ iodide could plausibly contribute to iodine-pool changes affecting thyroid function. Research protocols should consider alternative salt forms or iodide-pool monitoring for chronic-dosing studies. No serious adverse events have been documented in any published 5-Amino-1MQ research. The acute safety profile in research animals is favourable; chronic and human safety remains uncharacterised.

UK regulatory status

5-Amino-1MQ is not authorised as a medicinal product by the UK Medicines and Healthcare products Regulatory Agency (MHRA) and holds no marketing authorisation in any jurisdiction. It is not a controlled substance under the Misuse of Drugs Act 1971. The compound is a small molecule rather than a peptide, but the regulatory framework applicable in the UK is the same — supply or administration to humans outside an authorised clinical-trial framework engages the Human Medicines Regulations 2012 and is generally an offence. Research-grade material for in-vitro and animal research is available from research-chemical suppliers; possession for bona fide laboratory research is generally unrestricted in the UK. 5-Amino-1MQ is not currently on the WADA Prohibited List. The compound's mechanism (NNMT inhibition affecting adipose and skeletal-muscle metabolism) does not currently fall within any WADA category, but athletes should verify the current annual Prohibited List as classifications can change with emerging compounds. For animal research under ASPA, 5-Amino-1MQ work in vertebrates requires standard project and personal licences from the Home Office Drugs and Firearms Licensing Unit.

Frequently asked questions