Peptide Reference Desk
Humanin vs MOTS-c: two mitochondrial peptides that should not share one evidence file
Humanin and MOTS-c are both mitochondrial-derived peptides, but their sequences, discovery histories, assays and evidence cannot be treated as interchangeable.
Same family label, different molecules
Humanin and MOTS-c are often placed side by side in “mitochondrial peptide” roundups. That is a useful filing category, not a claim that they do the same job. They have different sequences, arise from different mitochondrial open reading frames and are studied with different assay traditions.
Humanin entered the literature through cytoprotection and cell-survival research. MOTS-c is more often discussed through metabolic stress and exercise-related signaling. Those summaries are starting points for a PubMed search, not substitutes for reading the experiment.
The comparison that actually helps
| Question | Humanin record | MOTS-c record |
|---|---|---|
| What was tested? | Humanin or a named analogue | MOTS-c with disclosed sequence |
| Model | Cell stress, neural, metabolic or aging model | Cellular metabolism, animal or human research |
| Endpoint | Survival, signaling or disease-model marker | Metabolic or stress-response endpoint |
| Identity | Expected mass for the stated Humanin form | Expected mass for MOTS-c |
Do not cite a Humanin analogue paper as evidence for native Humanin without naming the substitution. The same rule applies to MOTS-c analogues and modified constructs.
What the COA cannot leave vague
“Mitochondrial peptide, 99%” is not an adequate identity statement. The certificate should carry the full sequence, terminal form, expected mass, observed LC-MS result, HPLC method, content basis and lot identifiers. Oxidation-prone residues and related substances deserve method-specific attention.
Bottom line
The interesting scientific question is not which peptide wins a longevity ranking. It is whether a particular sequence changed a prespecified endpoint in a defined model, and whether the material in hand matches that sequence.
Check the primary record
Use a primary paper, regulator document or lot-linked analytical file for the claim it actually supports. Record the access date for time-sensitive status information.