Metabolic · 7 min read · Published September 8, 2026

SLU-PP-332 and 5-Amino-1MQ: Two 'Peptides' That Are Not Peptides, and What the Mouse Data Actually Show

Both are sold next to peptides and searched as peptides. Both are small molecules with animal data only. What SLU-PP-332 does to muscle in mice and why its heart safety is unknown; what 5-amino-1MQ does to fat cells and why it is on Amazon without a single human trial.

What is SLU-PP-332 and is it bad for your heart?

SLU-PP-332 is a small molecule, not a peptide, that activates estrogen-related receptors to mimic endurance-exercise signaling in muscle. All efficacy data come from cells and mice. No human trial has been run, and because ERR-alpha is expressed in heart tissue, its cardiac safety in people is unknown. It is also detectable in anti-doping tests.

The compound came out of Thomas Burris's lab at Saint Louis University and was described in a 2023 paper as a pan-ERR agonist. Estrogen-related receptors, despite the name, do not bind estrogen; they are master regulators of mitochondrial biogenesis and oxidative metabolism in muscle. Turning them on with a drug is a plausible route to an exercise mimetic, which is exactly how it was pitched in the American Chemical Society's press release 'Mimicking exercise with a pill'. Our profile is at SLU-PP-332.

What the SLU-PP-332 mouse studies showed

• In the 2023 and 2024 papers (Billon and colleagues), 28 days of dosing increased the proportion of fatigue-resistant oxidative muscle fibers, raised running endurance, and reduced fat mass in mice on a normal diet and in obese mice (PMC10801787).
• Energy expenditure went up without a change in food intake, which is the pattern people hope for.
• The doses were 50 mg/kg twice daily by injection, far above what capsule sellers suggest, and the animals were dosed for four weeks, not months.

What are the results of SLU-PP-332 for fat loss?

In mice, about 12 percent less fat mass after 28 days with no reduction in food intake. In humans, none, because no human study exists. Reports from people taking capsules are uncontrolled and the products are untested.

What does 5-amino-1MQ do?

5-amino-1MQ is a small-molecule inhibitor of NNMT, an enzyme that rises in fat tissue and slows fat-cell metabolism. In obese mice it reduced body weight and fat-cell lipid production. It is not a peptide, not FDA-approved, and has no completed human trials, despite being sold as a capsule on major retail sites.

NNMT (nicotinamide N-methyltransferase) consumes nicotinamide and the methyl donor SAM. In fat tissue it is elevated in obesity and insulin resistance, and blocking it makes fat cells burn more and store less. The University of Texas group led by Stanton McHardy and Harshini Neelakantan built 5-amino-1MQ as a membrane-permeable NNMT inhibitor; in 2018 they reported that diet-induced obese mice treated three times daily lost weight and fat and that fat-cell lipogenesis fell by half to two thirds in culture (PMC5826726). A 2022 study combined it with a reduced-calorie diet in mice (PMC8748953). Profile: 5-amino-1MQ.

Is 5-amino-1MQ FDA approved?

No. It has never been submitted for approval, it is not a dietary ingredient, and it was not among the substances reviewed for compounding in July 2026. Capsules sold by online retailers are unapproved products with no verified content.

Two claims recur. 'It shrinks fat cells': in culture and in mice, it reduces lipid accumulation in fat cells; nobody has measured fat cells in a person taking it. 'It boosts NAD+': NNMT inhibition spares nicotinamide, so NAD+ might rise; that is a hypothesis, and the direct NAD+ precursors have far more human data (see NMN vs NR vs NAD+).

Why both get called peptides

Because they are sold by peptide vendors, in the same vials and capsules, to the same customers. 'SLU-PP-332 peptide' and '5-amino-1MQ peptide' are common searches for that reason. Chemically, a peptide is a chain of amino acids; SLU-PP-332 is a phenol-hydrazone small molecule and 5-amino-1MQ is a quinolinium salt. The distinction matters for absorption (small molecules survive the gut, peptides mostly do not), for detection, and for how you read the evidence.

Where they sit against the alternatives