MOTS-c and KPV: two research peptides that fit no family

MOTS-c and KPV share a page because neither belongs to a family. MOTS-c is a 16-residue peptide encoded in mitochondrial DNA; KPV is a three-residue fragment cut from the end of a hormone, alpha-MSH. Neither is an analogue engineered to improve on a hormone, neither has a licensed medicine as a relative, and both are studied almost entirely in cells and animals.

Why most research peptides have a family, and these two don't

Most of what a research-peptide catalogue holds sorts cleanly into groups, each built around one hormone or receptor:

• Incretin analogues, built on GLP-1 or GIP and engineered for a long half-life: semaglutide vs tirzepatide vs retatrutide.
• GHRH analogues, modified copies of growth-hormone-releasing hormone: CJC-1295 vs tesamorelin.
• Tissue-repair peptides, fragments or copies of naturally occurring sequences: BPC-157 vs TB-500.

Each of those families has a pillar comparison, because the members answer to the same receptor or the same research question and people naturally ask how they differ.

MOTS-c and KPV answer to neither. They do not act at a shared receptor, they did not come out of a shared design programme, and there is no licensed member of their "family" to compare them against. What they have in common is only that: each stands alone, and each is small enough that its identity can be checked cleanly by mass.

At a glance

Masses are from PubChem. For comparison, an incretin analogue is roughly 4,100 to 4,800 Da, so MOTS-c is about half that size and KPV about a fourteenth.

MOTS-c: a peptide from the second genome

Human cells carry two genomes, and the mitochondrial one was long understood to encode just thirteen proteins. MOTS-c was found in 2015 by Lee and colleagues as a 16-amino-acid peptide read from a short open reading frame inside the mitochondrial 12S ribosomal RNA gene. Its name spells that out: mitochondrial open reading frame of the 12S rRNA type-c. It belongs to a small group, the mitochondrial-derived peptides, that also includes humanin.

What has been studied, at the level of the models used:

• The discovery paper (Lee et al., 2015) reported work in cultured cells and in mice, pointing at the folate cycle and at AMP-activated protein kinase (AMPK), the cell's low-energy sensor.
• Nuclear signalling. Kim and colleagues (Cell Metabolism, 2018) reported in cultured cells that under metabolic stress, such as glucose restriction, MOTS-c moves into the nucleus in an AMPK-dependent way and interacts with stress-responsive transcription factors. A peptide encoded in the mitochondria regulating genes in the nucleus is the unusual part.
• Muscle. Reynolds and colleagues (Nature Communications, 2021) studied MOTS-c in skeletal muscle, including in young, middle-aged and old mice.

The full explainer, including why a peptide inside a ribosomal RNA gene went unnoticed for decades, is MOTS-c, explained.

KPV: three residues off the end of a hormone

Alpha-melanocyte-stimulating hormone, alpha-MSH, is a 13-amino-acid peptide cleaved from pro-opiomelanocortin, best known for driving pigmentation through melanocortin receptors. Its pigmentation activity depends on a core at positions 6 to 9. KPV is positions 11 to 13, lysine-proline-valine, and does not contain that core.

That separation is the reason KPV is studied on its own. Researchers interested in the inflammatory-signalling side of alpha-MSH, without its pigmentation activity, can study the tail fragment in isolation.

What has been studied, at the level of the models used:

• Inflammatory signalling. Brzoska and colleagues reviewed alpha-MSH and its related tripeptides in Endocrine Reviews in 2008, covering in-vitro and in-vivo work on pathways including NF-kappa-B activation.
• Transport. Dalmasso and colleagues (Gastroenterology, 2008) examined whether KPV is carried into cells by PepT1, an intestinal di- and tripeptide transporter, using human intestinal epithelial and immune cell lines and two mouse colitis models.

That second strand is why KPV comes up whenever peptides and the gut are discussed together: most peptides are digested long before they could be absorbed, and a tripeptide small enough to use an existing transporter is a different case. Why most peptides do not survive the gut. The full explainer is KPV, explained.

Regulatory status

Neither is a licensed medicine anywhere. MOTS-c and KPV hold no marketing authorisation from the MHRA, the EMA, the FDA or any other regulator. There is no licensed product to measure a research supply against, which is a genuine difference from tirzepatide, where a licensed medicine exists. Approved, licensed, or neither.

In the UK both may lawfully be bought, sold and held for laboratory research, and neither may be sold or advertised for human or veterinary use. What that permission covers.

Anti-doping is a separate question, and the two differ. The 2026 WADA Prohibited List, in force from 1 January 2026, names MOTS-c explicitly under S4.4.1, among activators of AMPK, in a section prohibited at all times. KPV is not named, but S0 covers any pharmacological substance with no current approval by a governmental health authority for human therapeutic use and not addressed elsewhere on the list, which describes KPV. Which peptides are on the WADA list.

Testing notes

Both are small enough that mass spectrometry is a strong identity check, which is useful for compounds with no licensed reference product and comparatively little independent scrutiny.

1. Identity. The observed mass should agree with about 2,175 Da for MOTS-c and about 342 Da for KPV. A number well away from either is a different molecule. How to read a certificate.
2. Purity, with the method named. What HPLC and mass spectrometry each tell you.
3. Quantity, which purity does not describe. Ninety-nine per cent pure is not ten milligrams.
4. Batch traceability: certificate, carton and batch lookup in agreement.
5. Storage: 2 to 8°C, dark, not frozen.

A tripeptide is cheap to make, which cuts both ways: there is little reason to adulterate it, and little friction for anyone selling material that was never properly characterised. A 16-residue peptide from a young literature has the opposite problem: fewer people have checked what is on the market. Either way, the certificate is where the answer is.

How Biovanta will supply them

Neither is on sale yet. When they are, MOTS-c 40 mg and KPV 10 mg will each come in a factory-sealed pre-filled pen with sterile needles and prep swabs, manufactured in Switzerland and dispatched from the UK. The testing page shows which batches have an independent Janoshik report and lets you check each one by key on the laboratory's own site. Both will be supplied strictly for in-vitro laboratory research.