Beyond the incretins, our range has three molecules described as metabolic: MOTS-c, SLU-PP-332 and HGH Fragment 176-191. Each works by a different route, and what they share is what they lack: a result in humans. Below is what has been shown for each of them, what a milligram costs, and how they differ from semaglutide and its relatives.
What each of them does
| Molecule | Mechanism | Where studied |
|---|---|---|
| MOTS-c | A 16 amino acid peptide encoded by mitochondrial DNA; activates the AMPK kinase in muscle | Mice, plus observations in humans |
| SLU-PP-332 | A pan-agonist of ERR receptors; switches on the gene programme triggered by exercise | Mice |
| HGH Fragment 176-191 | The end section of growth hormone linked to fat breakdown; does not raise IGF-1 | Mice and one human study |
MOTS-c: strong data in mice, observations in humans
In mice on a high-fat diet, strong AMPK activation was described. Expression of the glucose transporter GLUT4 in muscle also rose. The effects included faster clearance of glucose from the blood and an increase in insulin sensitivity of about 30 per cent. Prevention of age-related insulin resistance was also described.
In humans the data are observational, not interventional. The level of circulating MOTS-c correlates with markers of insulin resistance and obesity: BMI, waist circumference, fasting insulin and HbA1c. That means people with worse results have lower measured levels. It does not mean that giving the peptide improves those results. The whole picture is in the guide to MOTS-c as a mitochondrial peptide.
SLU-PP-332: a molecule that is not a peptide
This is a synthetic small molecule, sold alongside peptides although it is not one. A single dose in mice switched on a gene programme corresponding to acute aerobic exercise. Mitochondrial respiration, fatty acid oxidation and energy expenditure rose with it.
No clinical studies have been run in humans, so there is no established dose and no described human safety profile. The trade description about exercise in a pill describes a mechanism observed in rodents, not a human result, as the guide to SLU-PP-332 explains.
HGH Fragment 176-191: strong in mice, tested in humans as AOD9604
In obese mice the fragment, in its modified version AOD9604, reduced body weight and body fat and increased fat burning. We found no published clinical trial of fragment 176-191 itself; in humans it was AOD9604 that was tested.
Its modified version AOD9604 did not reach its primary endpoint in a phase 2b trial, and its development was stopped in 2007. These two sentences are worth reading together: the animal result is the one advertising uses, and the human result is the one that decided the molecule's fate. This is covered in more depth in the guide to HGH Fragment 176-191 and growth hormone.
What a milligram costs
| Product | Contents | Price | Price per milligram |
|---|---|---|---|
| MOTS-c, Bio-Peptide | 10 mg | 45 EUR | 4.50 EUR |
| SLU-PP-332, Bio-Peptide | 5 mg | 50 EUR | 10 EUR |
| HGH Fragment, Bio-Peptide or Genheal | 5 mg | 25 EUR | 5 EUR |
| HGH Fragment, Nouveaux Ltd. | 10 mg | 55 EUR | 5.50 EUR |
With the fragment a larger vial brings no saving, because it costs slightly more per milligram. What does matter is stability: the dissolved fragment loses activity faster than most of the catalogue, after roughly two weeks in the fridge according to user reports. Conditions are given in the guide to storing peptides.
How this trio differs from the incretins
The difference is not strength of action but the kind of evidence. Semaglutide, tirzepatide and retatrutide have phase 3 clinical trials in humans behind them. Two of them are also approved medicines. The mechanism of that whole group is set out in the guide to GLP-1 incretins, and a side-by-side in the comparison of the three weight loss peptides.
The whole trio in this guide is sold as material for laboratory research, without approval and without an established human dose, and for that reason we publish no protocols with it. All items are in the weight loss peptides category.
Frequently asked questions
Which of the three has the best evidence?
None has a positive result in humans. Of the three, only HGH Fragment has human data, through its modified version AOD9604, which missed the main endpoint of a phase 2b trial.
Does MOTS-c improve insulin sensitivity in humans?
It did in mice. In humans only observational links between MOTS-c levels and metabolic markers have been described.
Is SLU-PP-332 a peptide?
No. It is a synthetic small molecule acting on ERR receptors.
Why does HGH Fragment not raise IGF-1?
It lacks the part of the growth hormone molecule that binds the receptor, and that is the point of using the fragment alone.
What is the cheapest milligram of the three?
4.50 EUR, for MOTS-c in a 10 mg vial at 45 EUR.
This is information about products and the state of research, not medical advice. We sell all three molecules as material for laboratory research.
Prices and full descriptions of the first two are on the MOTS-c and SLU-PP-332 pages.
Sources
- Lee C, Zeng J, Drew BG et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metabolism, 2015, 21(3): 443-454. https://doi.org/10.1016/j.cmet.2015.02.009
- Du C, Zhang C, Wu W et al. Circulating MOTS-c levels are decreased in obese male children and adolescents and associated with insulin resistance. Pediatric Diabetes, 2018. https://doi.org/10.1111/pedi.12685
- Billon C, Sitaula S, Banerjee S et al. Synthetic ERRα/β/γ Agonist Induces an ERRα-Dependent Acute Aerobic Exercise Response and Enhances Exercise Capacity. ACS Chemical Biology, 2023, 18(4): 756-771. https://doi.org/10.1021/acschembio.2c00720
- Billon C, Schoepke E, Avdagic A et al. A Synthetic ERR Agonist Alleviates Metabolic Syndrome. Journal of Pharmacology and Experimental Therapeutics, 2024, 388(2): 232-240. https://doi.org/10.1124/jpet.123.001733