5-amino-1MQ: what the NNMT inhibitor does and where the evidence ends

A small molecule in a peptide catalog

It is worth starting with what 5-amino-1MQ is not. It has no peptide bonds: it is 5-amino-1-methylquinolinium, a low-molecular-weight aromatic cation from a series of NNMT inhibitors characterized in 2017 by a group at the University of Texas Medical Branch in Galveston. In that series, methylated quinoliniums inhibited the enzyme with an IC50 of about 1 µM and, according to molecular docking, would bind selectively to the nicotinamide site⁴. It appears alongside peptides because it shares the same audience interested in metabolism and longevity, and because researchers handle it with the same laboratory protocols. The technical sheet is at 5-Amino-1MQ.

The enzyme: NNMT, between NAD⁺ and methylation

NNMT methylates nicotinamide (vitamin B3) using S-adenosylmethionine (SAM) as the methyl donor. That links two systems: the nicotinamide pool the cell would use to regenerate NAD⁺, and the methyl-group balance that regulates, among other things, histone methylation¹². A highly active NNMT, in theory, diverts NAD⁺ precursors and consumes SAM.

The work that put the enzyme on the map was Kraus and colleagues in Nature (2014). NNMT expression was increased in white adipose tissue and liver of obese and diabetic mice, and knocking it down in those tissues protected against diet-induced obesity by increasing cellular energy expenditure. Inhibition raised adipose NAD⁺ and SAM. The authors concluded that NNMT is "a unique and attractive target for treating obesity and type 2 diabetes"¹.

The signal has an observational human correlate. In 199 patients undergoing abdominal surgery, adipose NNMT expression was roughly twofold higher in those with type 2 diabetes and correlated with insulin resistance; exercise and bariatric surgery were associated with a significant reduction in that expression³. This is an association, not proof that inhibiting the enzyme benefits people.

Obesity in mice: what 5-amino-1MQ showed

In 2018 the same group tested the compound in adipocytes and mice. In culture, the inhibitors reduced the enzyme's product (1-methylnicotinamide), raised intracellular NAD⁺ and SAM and suppressed lipogenesis; 5-amino-1MQ did not inhibit related methyltransferases or NAD⁺ salvage enzymes⁵. In male mice with diet-induced obesity, treated subcutaneously for 11 days, it was associated with a significant reduction in body weight and white fat mass, smaller adipocytes and lower total cholesterol, with no change in food intake and no observable adverse effects⁵.

Later studies widened the picture. Combined with a switch to a lean diet, an NNMT inhibitor normalized body composition and liver adiposity to the levels of lean control mice, better than diet alone⁶. In 2024, 28 days of 5-amino-1MQ in obese mice dose-dependently limited weight and fat gain, improved oral glucose tolerance and insulin sensitivity, attenuated hepatic steatosis and normalized transaminases⁷.

Aged muscle: stem cells and strength

NNMT rises with age in skeletal muscle. In 24-month-old mice with an acute tibialis anterior injury, the inhibitor (5 and 10 mg/kg) increased muscle stem cell proliferation and fusion, with nearly 2-fold greater fiber cross-sectional area and roughly 70% higher peak torque than controls⁸. In mice treated from 22 to 24 months of age, grip strength was about 40% greater than in sedentary controls, versus 20% with exercise alone and 60% with both combined⁹.

An independent group reported a result along the same lines in 2025: in mice with hindlimb ischemia (n = 24), NNMT inhibition improved strength (p < 0.0001), power and total work of the ischemic muscle without changing perfusion. In the same study, NNMT was elevated in muscle from patients with peripheral artery disease¹¹.

The link to NAD⁺ and longevity

The longevity field's interest comes from the NAD⁺ pathway: rather than supplying precursors, NNMT inhibition aims to have the cell divert less nicotinamide, with NAD⁺ increases seen in mouse adipocytes and adipose tissue¹⁵. In 2026, a kidney study linked NNMT to tubular senescence and fibrosis in human biopsies, and selective inhibition of the enzyme was protective in cells, organoids and mice¹². For the broader picture of NAD⁺, MOTS-c and other longevity molecules, see Epitalon, MOTS-c, NAD+ and SS-31.

Where the evidence ends

Everything above comes from cells and rodents. A ClinicalTrials.gov search returns no registered study of 5-amino-1MQ, and PubMed contains no human trials¹³. The published pharmacokinetic data are from rats: oral bioavailability of 38.4% and terminal half-life of 3.80 h intravenously and 6.90 h orally¹⁰. No half-life, effective dose or safety profile has been established in humans.

• Short duration: efficacy studies last from 11 to 28 days or a few weeks, mostly in male mice⁵⁷⁸.
• One dominant group: most 5-amino-1MQ work comes from the Watowich and Neelakantan laboratory; several papers disclose that the founder and employees belong to Ridgeline Therapeutics, which develops NNMT inhibitors⁶⁷⁹.
• Double-edged biology: NNMT has beneficial roles in the liver and its role varies by tissue, so blocking it systemically is not a neutral effect by definition².
• The human link is correlational: elevated NNMT in adipose tissue of people with diabetes does not show that inhibiting it improves clinical outcomes³.