Humanin vs SS-31 (Elamipretide)
Humanin (Mitochondrial-derived peptide) and SS-31 (Elamipretide) (Mitochondria-targeted tetrapeptide) are documented as co-studied in the PeptiDex library. This page puts the two entries side by side on class, molecular weight, half-life, origin, mechanism and studied research areas — every value taken from the entry it belongs to.
Why these two are co-studied
Cross-referenced for research context — not a usage or combination recommendation.
At a glance
| Attribute | Humanin | SS-31 (Elamipretide) |
|---|---|---|
| Compound class | Mitochondrial-derived peptide | Mitochondria-targeted tetrapeptide |
| Research category | Longevity & Cellular | Longevity & Cellular |
| Length (amino acids) | 24 amino acids | 4 amino acids |
| Molecular weight | 2687 g/mol (approx., 24-aa form) | 639.8 g/mol (approx.) |
| Half-life | Not documented | Not documented |
| Origin | Humanin is a small mitochondrial-derived peptide encoded within the mitochondrial 16S ribosomal RNA gene (MT-RNR2). It was identified in the early 2000s from surviving neurons in Alzheimer's disease brain tissue and is one of the first characterized mitochondrial-derived peptides. | SS-31 (elamipretide, also known as MTP-131 or Bendavia) is a synthetic, cell-permeable, mitochondria-targeted tetrapeptide developed from the Szeto-Schiller (SS) family of aromatic-cationic peptides. It is one of the most studied members of that peptide series. |
“Not documented” means the PeptiDex entry records no value for that field. Nothing on this page is estimated, and no figure is carried over from one compound to the other.
How Humanin works
Humanin is reported to have cytoprotective and anti-apoptotic effects. Described mechanisms include interaction with pro-apoptotic Bcl-2 family proteins (such as Bax and BID) and signaling through a cell-surface receptor complex, with downstream effects on cell survival pathways. It has also been studied for roles in metabolic regulation and insulin sensitivity. Both a 24-amino-acid form (mitochondrial translation) and a 21-amino-acid form (cytoplasmic translation) have been described.
How SS-31 (Elamipretide) works
SS-31/elamipretide selectively concentrates in the inner mitochondrial membrane, where it is reported to bind the phospholipid cardiolipin. By associating with cardiolipin, it is proposed to stabilize the structure of the inner membrane and cristae, support electron transport chain organization and efficiency, and reduce excessive reactive oxygen species production. These actions are intended to improve mitochondrial bioenergetics under conditions of mitochondrial dysfunction.
Mechanistic descriptions reflect published research-literature understanding and are quoted from each compound's own entry. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
Where each one appears in the literature
The research contexts each entry documents. Listing a research area is not a claim of efficacy or a therapeutic indication, and the two lists are not scored against each other.
Humanin
SS-31 (Elamipretide)
What sets each apart
Humanin
Humanin is a naturally encoded mitochondrial-derived signaling peptide focused on cytoprotection and metabolism, distinct from the synthetic mitochondria-targeting SS-31 and from immune or pineal peptides.
SS-31 (Elamipretide)
SS-31 is a synthetic mitochondria-targeting tetrapeptide that physically localizes to the inner membrane and binds cardiolipin, and unlike most peptides here it has advanced into human clinical trials as elamipretide.
Frequently asked questions
What is humanin?
Humanin is a 24-amino-acid mitochondrial-derived peptide (MDP) encoded within the 16S rRNA region of mitochondrial DNA, discovered in 2001. It is the founding member of the mitochondrial-derived peptide family and is studied for cytoprotective, neuroprotective, and metabolic effects.
What is the sequence and molecular weight of humanin?
Humanin's sequence is MAPRGFSCLLLLTSEIDLPVKRRA, a 24-residue peptide with an approximate molecular weight of about 2687 Da. Some research analogs (e.g. HNG, with a Ser14Gly substitution) are more potent variants used in studies.
What is humanin studied for?
Preclinical research has examined humanin for neuroprotection against amyloid-beta toxicity, cardioprotection in ischemia-reperfusion injury, insulin sensitization via central STAT3 signaling, and anti-apoptotic effects through BAX antagonism. These are cell and animal findings, not established human therapies.
What is SS-31 (elamipretide)?
SS-31 (elamipretide, also known by the codes Bendavia and SS-31) is a mitochondria-targeted tetrapeptide, D-Arg-Dmt-Lys-Phe-NH2, that concentrates in the inner mitochondrial membrane by binding cardiolipin. It is studied in models of mitochondrial dysfunction, heart failure, ischemia-reperfusion, and age-related bioenergetic decline.
How does SS-31 target mitochondria?
Its alternating cationic and aromatic residues give it strong affinity for cardiolipin, a phospholipid found almost exclusively on the inner mitochondrial membrane. By binding cardiolipin it is thought to stabilize cristae structure and improve electron-transport efficiency, reducing reactive oxygen species.
What is the sequence and molecular weight of SS-31?
SS-31 is the tetrapeptide D-Arg-2',6'-dimethyltyrosine-Lys-Phe-NH2 (D-Arg-Dmt-Lys-Phe-NH2), with molecular formula C32H49N9O5 and a molecular weight of about 639.8 g/mol. The unusual dimethyltyrosine and C-terminal amide are defining features.
Answers are the ones published on each compound's own PeptiDex entry. They are educational summaries of research-literature context and are not medical advice.