5-Amino-1MQ

01 · What it is

5-Amino-1MQ is not a peptide. It is a small-molecule enzyme inhibitor — a methylated quinolinium salt — and it appears in this project only because it is sold and discussed alongside research peptides.

Its entire published evidence base is six papers. This guide cites all six.

Worth noting before anything else: the name the compound is sold under does not exist in PubMed’s phrase index. A search for the exact string “5-amino-1MQ” returns the message that the quoted phrase is not indexed. The molecule is real and it does appear in the literature — as 5-amino-1-methylquinolinium, usually as its iodide salt, and often just as “NNMTi” — but the abbreviation used commercially has no presence in the scientific record at all.

The target is nicotinamide N-methyltransferase, NNMT. This enzyme takes nicotinamide — the salvage substrate that cells recycle back into NAD+ — and methylates it, using S-adenosylmethionine as the methyl donor. The product, 1-methylnicotinamide, is excreted. So NNMT does two things at once that matter for the rationale: it drains the nicotinamide pool away from NAD+ resynthesis, and it consumes methyl groups.

NNMT expression in adipose tissue rises in obesity and diabetes ³. Adipose tissue expresses enzymatically active NNMT in quantity, in 3T3-L1 adipocytes and in human and murine adipose explants ¹. The inhibition hypothesis follows: block NNMT in fat, preserve nicotinamide for NAD+, shift adipocyte metabolism.

The founding result is real and it is in mice. A group at the University of Texas Medical Branch investigated the permeability, selectivity and physiological properties of a series of small-molecule NNMT inhibitors, and reported that systemic treatment of diet-induced obese mice with a potent inhibitor reversed high-fat-diet-induced obesity ².

The most-cited weight-loss finding required a diet alongside the drug, and this is routinely dropped. The 2022 study that reported dramatic whole-body adiposity and weight loss in diet-induced obese mice used the NNMT inhibitor combined with a low-fat diet, and the paper’s own framing is that the combination rapidly normalised those measures ⁵. The comparison in that study was against the obesogenic diet, not against the low-fat diet alone.

No human has been given this compound. Six indexed records, none of them a clinical trial, none of them in a person.

02 · Evidence at a glance

Evidence grade

Preclinical — no human study of any kind is indexed

Chemical class

A small-molecule enzyme inhibitor, not a peptide

Full name

5-amino-1-methylquinolinium, usually studied as the iodide salt

Name recognition in PubMed

“5-amino-1MQ” is not in PubMed’s phrase index

Target

Nicotinamide N-methyltransferase (NNMT)

What NNMT does

Methylates nicotinamide using S-adenosylmethionine; diverts it from NAD+ salvage

Rationale

NNMT expression rises in adipose tissue in obesity and diabetes ³

Total indexed records

6

Human trials

None

Human subjects to date

0

Founding result

Reversal of high-fat-diet-induced obesity in mice ²

Key qualification

The dramatic weight-loss result used the inhibitor plus a low-fat diet ⁵

Oncology signal

Reduced tumour growth and enhanced anti-PD-L1 effect in bladder cancer mouse models ⁶

Approval status

None, any jurisdiction

03 · Mechanism of action

The enzyme, and the two things it consumes

NNMT catalyses one reaction: nicotinamide plus S-adenosylmethionine gives 1-methylnicotinamide plus S-adenosylhomocysteine. That single reaction has two consequences the inhibition hypothesis depends on.

The first is metabolic. Nicotinamide is the substrate cells use to regenerate NAD+ through the salvage pathway. Every molecule NNMT methylates is a molecule that cannot re-enter that pathway. In a tissue where NNMT is highly expressed, the enzyme is a drain on NAD+ regeneration capacity.

The second is methylation. S-adenosylmethionine is the universal methyl donor, used for DNA methylation, histone methylation and hundreds of other reactions. NNMT consumes it and produces S-adenosylhomocysteine, which is hydrolysed to homocysteine.

That second consequence has a documented physiological readout. Homocysteine — described in the primary literature as the atherogenic product of the NNMT-catalysed reaction — was shown to be secreted from 3T3-L1 adipocytes, with adipose tissue identified as a source of both the enzyme and the metabolite ¹.

Inhibiting NNMT should therefore reduce homocysteine production in adipose tissue, which is a plausible collateral benefit. No study in this file has measured it after inhibition, and it is reported here as a mechanistic implication rather than a finding.

Why adipose tissue

NNMT expression in adipose tissue is increased in obesity and diabetes ³, and glucose availability regulates its expression in adipocytes ³. Adipose tissue expresses substantial enzymatically active NNMT ¹. That combination — a druggable enzyme, upregulated in the disease state, in the tissue of interest — is what made it a target.

The chemistry problem the founding paper solved

The 2018 paper’s contribution was not the idea of inhibiting NNMT but the demonstration that it could be done with a molecule that gets into cells. The investigators examined permeability, selectivity, mechanism and physiology across a series of inhibitors, and validated NNMT as an anti-obesity target by showing that a potent, selective, membrane-permeable inhibitor reversed diet-induced obesity in mice when given systemically ².

A quaternary quinolinium salt carries a permanent positive charge, which ordinarily impedes membrane crossing. That the paper foregrounds permeability indicates the authors regarded it as the central technical question, and it remains the unexamined question for any oral commercial preparation.

04 · Key research findings

Obesity reversal in mice. Systemic treatment of diet-induced obese mice with a potent NNMT inhibitor reversed high-fat-diet-induced obesity, in a study designed to validate NNMT as an anti-obesity drug target through permeability, selectivity, mechanistic and physiological characterisation ².

The single most important result for this compound, and the reason it is sold. One study, in mice, from one group.

Weight loss with a diet, and the microbiome. Treatment with the NNMT inhibitor 5-amino-1-methylquinolinium combined with a low-fat diet promoted dramatic whole-body adiposity and weight loss in diet-induced obese mice, rapidly normalising those measures, and established a distinct gut microbiome relative to comparators ⁵.

This is the study most often invoked for the magnitude of the effect, and the intervention was drug plus dietary change. Any account that reports the weight loss without the diet is reporting something the paper did not test.

Enzyme regulation. Glucose availability regulates NNMT expression in adipocytes, with adipose tissue-specific manipulation of GLUT4 affecting it ³. Adipose tissue was identified as a source of both NNMT and homocysteine, with enzymatically active NNMT found in 3T3-L1 adipocytes and in human and murine adipose explants ¹.

Both are studies of the enzyme rather than of the inhibitor, and both predate the therapeutic programme. They establish that the target is real and regulated. They say nothing about blocking it.

Oncology, in two directions. In urothelial bladder cancer, NNMT in cancer-associated fibroblasts was found to drive tumour progression and resistance to immunotherapy by modulating macrophages, and 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 ⁶. In cervical cancer cells, a related small-molecule NNMT inhibitor showed anti-proliferative activity in HeLa cells ⁴.

Two independent groups reporting anti-tumour activity is the most encouraging pattern in this small file, and it is a different indication from the one the compound is sold for.

05 · Evidence overview

06 · Safety profile

Animal data. No formal toxicology programme is identified. The mouse studies report body composition, weight and microbiome endpoints ^2,5 and tumour endpoints ⁶, none designed to find a toxic dose.

Human data. None exists. There is no reported human exposure to 5-amino-1-methylquinolinium in the peer-reviewed literature at any dose, by any route, for any duration.

What is genuinely unknown. Nearly everything, and the specific unknowns follow from the mechanism rather than being generic. NNMT is not confined to adipose tissue — it is expressed most abundantly in liver, where it is a principal route of nicotinamide clearance, and inhibiting it systemically would be expected to alter hepatic nicotinamide handling in ways nothing in this file has measured. S-adenosylmethionine consumption by NNMT is a real methyl sink; blocking it changes methyl group availability, and the consequences for DNA and histone methylation have not been examined in any animal. 1-methylnicotinamide, the product, has proposed biological activities of its own, so inhibition removes a metabolite as well as sparing a substrate. Oral bioavailability of a permanently charged quaternary salt, unreported for any species, despite oral administration being how the compound is sold. Pharmacokinetics and tissue distribution, absent. Repeat-dose toxicology, genotoxicity, reproductive toxicology and carcinogenicity: none performed. And the identity and purity of any commercial preparation, on which no published analysis exists — with the additional complication that the commercial name does not correspond to any indexed chemical designation, so a purchaser has no published reference standard to compare against.

07 · US regulatory status

Current as of 6 September 2026. 5-Amino-1-methylquinolinium is not approved as a drug in the United States or any other jurisdiction and is not a controlled substance.

It is not a dietary ingredient with any established regulatory history, it is not a peptide, and it has no investigational new drug programme in the peer-reviewed record. It is a laboratory chemical that has been used as a tool compound in six published studies.

Under the World Anti-Doping Code, metabolic modulators are prohibited under class S4, and substances not approved for human therapeutic use by any governmental regulatory health authority fall within class S0. Competitors should consult the current Prohibited List directly rather than rely on secondary summaries, including this one.

08 · Limitations of the evidence

1. Six papers is the whole literature. Not six selected papers — six is the total returned by a search covering the compound’s chemical name and its target in the relevant tissue. Every one is cited in this guide, which means this file has no depth to draw on and no negative results to weigh against the positive ones.
2. There is no human evidence of any kind.
3. The headline weight-loss result was drug plus diet. The study reporting dramatic adiposity and weight loss combined the NNMT inhibitor with a low-fat diet ⁵. Separating the drug’s contribution from the diet’s would require an arm that study did not report, and marketing claims that quote the magnitude without the diet are quoting something untested.
4. The obesity finding has not been independently replicated. Both obesity papers come from the same group ^2,5. The only independent work on this compound is in oncology ^4,6, and it concerns a different question.
5. Oral bioavailability is unreported and mechanistically doubtful. A quaternary ammonium compound carries a permanent positive charge. The founding paper treats membrane permeability as the central technical challenge ². No study reports oral absorption in any species, and oral is the route the compound is sold for.
6. Animal-to-human translation of an obesity result is historically poor. Diet-induced obese mice are a highly reproducible model that has produced many compounds which did not work in people. Nothing here is at the stage where translation could even be attempted.
7. The methylation consequences of inhibiting a methyltransferase are unexamined. NNMT consumes S-adenosylmethionine. Chronic inhibition changes the methyl economy of the cell, and no study in this file measured DNA methylation, histone methylation, or S-adenosylmethionine and S-adenosylhomocysteine concentrations after treatment.
8. Tissue selectivity is assumed rather than demonstrated in vivo. The rationale rests on NNMT being upregulated in adipose tissue ^1,3, but the enzyme’s highest expression is hepatic, and no study reports what systemic inhibition does to liver nicotinamide handling.
9. The commercial name has no scientific referent. “5-amino-1MQ” is not in PubMed’s phrase index. That is a small thing and it has a practical consequence: there is no published characterisation of a substance under that name to compare a product against.
10. Nothing is known about commercial material. No published analysis has examined the identity or purity of any product sold under this name.

09 · References

1. Riederer M, Erwa W, Zimmermann R, Frank S, Zechner R. Adipose tissue as a source of nicotinamide N-methyltransferase and homocysteine. Atherosclerosis. 2009 Jun;204(2):412–417.

   PMID 18996527 ↗

2. Neelakantan H, Vance V, Wetzel MD, Wang HL, McHardy SF, Finnerty CC, Hommel JD, Watowich SJ. Selective and membrane-permeable small molecule inhibitors of nicotinamide N-methyltransferase reverse high fat diet-induced obesity in mice. Biochem Pharmacol. 2018 Jan;147:141–152.

   PMID 29155147 ↗

3. Ehebauer F, Ghavampour S, Kraus D. Glucose availability regulates nicotinamide N-methyltransferase expression in adipocytes. Life Sci. 2020 May 1;248:117474.

   PMID 32112869 ↗

4. Akar S, Duran T, Azzawri AA, Koçak N, Çelik Ç, Yıldırım Hİ. Small molecule inhibitor of nicotinamide N-methyltransferase shows anti-proliferative activity in HeLa cells. J Obstet Gynaecol. 2021 Nov;41(8):1240–1245.

   PMID 33645410 ↗

5. Dimet-Wiley A, Wu Q, Wiley JT, Eswar A, Neelakantan H, Savidge T, Watowich S. Reduced calorie diet combined with NNMT inhibition establishes a distinct microbiome in DIO mice. Sci Rep. 2022 Jan 10;12(1):484.

   PMID 35013352 ↗

6. Yang M, Wang B, Hou W, et al. NAD+ metabolism enzyme NNMT in cancer-associated fibroblasts drives tumor progression and resistance to immunotherapy by modulating macrophages in urothelial bladder cancer. J Immunother Cancer. 2024 Jul 27;12(7):e009281.

   PMID 39067875 ↗