Epitalon vs SS-31
Epitalon and SS-31 are studied in overlapping research areas, which is why they are frequently compared. This is a neutral side-by-side reference drawn from published preclinical literature and laboratory handling data.
How they actually differ
Comparing the two: Epitalon is synthetic tetrapeptide (ala-glu-asp-gly), while SS-31 is mitochondria-targeting aromatic-cationic tetrapeptide (cardiolipin-binding) — different molecular classes with different handling consequences; they call for different primary diluents (sterile or bacteriostatic water versus bacteriostatic water (0.9% benzyl alcohol)); their leading degradation routes differ (aspartate-glycine isomerisation for Epitalon, adsorptive loss to plasticware from the cationic charge for SS-31), so the storage precautions that matter are not the same; their practical working windows differ once reconstituted. The sections below set out each in full.
Epitalon — origin
Epitalon is a four-residue peptide derived by Vladimir Khavinson's group from Epithalamin, a pineal gland extract studied in the Soviet Union from the 1970s. It represents the reductionist end of the peptide field — the attempt to identify the shortest sequence retaining the activity of a complex tissue extract. At 390 Da it is the smallest compound in this catalogue by a wide margin.
SS-31 — origin
SS-31 (Elamipretide) is a Szeto-Schiller aromatic-cationic tetrapeptide (D-Arg-2',6'-dimethyltyrosine-Lys-Phe-NH2) that concentrates in the inner mitochondrial membrane and binds cardiolipin, the lipid unique to that membrane. Its structure is the reason it is studied specifically at the mitochondrion rather than as a general antioxidant.
Epitalon research themes
The most-cited claim in the Epitalon literature, examined in cell-culture models.
Follows from its Epithalamin origin; studied for effects on circadian signalling in animal models.
A long-running Russian research programme examined lifespan endpoints in rodent models.
Epitalon is the flagship of Khavinson's "peptide bioregulator" framework, a distinct research tradition worth understanding as context.
SS-31 research themes
Studied for selective association with cardiolipin in the inner mitochondrial membrane, the basis of its mitochondrial targeting.
Examined for effects on mitochondrial energy production in research models of mitochondrial dysfunction.
Investigated around reactive-oxygen-species handling at the mitochondrion.
Epitalon handling
- Do not over-engineer storage for this compound — refrigeration and a sound seal are genuinely sufficient.
- Avoid prolonged storage of reconstituted solution, since Asp-Gly isomerisation is slow but cumulative.
- Verify the analytical method behind any purity figure, as short polar peptides are easy to under-resolve.
SS-31 handling
- Reach room temperature before opening.
- Use low-bind labware and buffers at low working concentrations to limit adsorption of the cationic peptide.
- Aliquot and refrigerate.
Both third-party tested
Every Popular Peptides batch of Epitalon and SS-31 is independently tested by HPLC and LC-MS with a published Certificate of Analysis. Enter a lot number to pull the COA for a specific vial.
Epitalon reference
Related comparisons
Epitalon and SS-31 are supplied strictly as research chemicals for in-vitro laboratory and research use only. They are not intended for human or animal consumption, diagnostic, or therapeutic use. This comparison summarizes published preclinical literature and laboratory handling data; it is not medical advice, not a claim of efficacy, and not usage guidance.