HEAD-TO-HEAD

SS-31 VS MOTS-c

SS-31 and MOTS-c are both mitochondrial-targeted research peptides, but they engage mitochondrial biology at completely different levels. SS-31 (elamipretide) is a synthetic 4-aa tetrapeptide that selectively binds cardiolipin on the inner mitochondrial membrane to stabilize cristae and preserve electron-transport-chain coupling. MOTS-c is an endogenous 16-aa peptide encoded by mitochondrial DNA that activates AMPK and translocates to the nucleus to modulate gene expression. Structural vs signaling.

A · No. 013

SS-31

Cardiolipin-binding mitochondrial tetrapeptide

B · No. 010

MOTS-c

Mitochondrial 16-AA Peptide

SIDE BY SIDE

FIELD

A · SS-31

B · MOTS-c

Class

Synthetic mitochondrial-targeted tetrapeptide

Mitochondrial-derived 16-aa peptide (MDP)

Encoded by

Synthetic (not naturally occurring)

Mitochondrial 12S rRNA short open reading frame

Sequence

D-Arg-(2',6'-dimethylTyr)-Lys-Phe-NH2

MRWQEMGYIFYPRKLR

Mechanism

Cardiolipin binding · inner-membrane structural stabilization · OXPHOS coupling preservation

AMPK activation · folate-cycle inhibition · nuclear translocation · gene-expression modulation

Half-life

~3 hours plasma

~30 min plasma (rodent), longer tissue residence

Research focus

Primary mitochondrial myopathy · Barth syndrome · dry AMD · cardiac ischemia-reperfusion

Insulin sensitivity · exercise-mimetic · age-related physical decline

Clinical-trial status

Stealth BioTherapeutics Phase 2/3 in multiple indications · regulatory packages submitted

Early-stage human trials · no Phase 3 completions

FDA status

Investigational · full FDA approval not granted as of 2026-05

Not FDA-approved · research-use only

WADA status

Not listed (2026)

WHICH IS BETTER · BY GOAL

▶ Structural mitochondrial-membrane researchA · SS-31

SS-31's cardiolipin-binding mechanism is the canonical structural-stabilization probe for the inner mitochondrial membrane (Szeto lab biochemistry). MOTS-c does not target membrane structure directly.

▶ Exercise-mimetic / aged-muscle researchB · MOTS-c

Reynolds 2021 (Nat Commun, PMID 33473109) reported improved treadmill performance and grip strength in aged mice with exogenous MOTS-c. SS-31 is not framed as an exercise mimetic.

▶ AMPK pathway researchB · MOTS-c

MOTS-c is the canonical AMPK-activating mitochondrial-derived peptide. SS-31 acts mechanically on cardiolipin, not on AMPK directly.

▶ Cardiac ischemia-reperfusion researchA · SS-31

Multiple rodent and large-animal models report SS-31 reduces infarct size and preserves ATP under ischemic stress (Szeto et al. 2011 J Am Soc Nephrol). MOTS-c not specifically a cardiac-ischemia compound.

▶ Insulin-sensitivity researchB · MOTS-c

MOTS-c has Lee 2015 (Cell Metab, PMID 25738459) in diet-induced obese mice reversing insulin resistance. SS-31 not specifically studied as an insulin-sensitivity agent.

STACKING NOTE

SS-31 + MOTS-c covers two non-overlapping layers of mitochondrial biology (membrane structure + AMPK signaling). No published RCT studies the combination, but mechanistic complementarity is the basis for the Cellular Bioenergetics research framing.

SOURCED FROM GIGACOMPOUNDS

Both compounds are available as research-grade material at GigaCompounds · ≥99% purity · per-batch CoA. For laboratory research use only.

SOURCE AT GIGACOMPOUNDS ▶