Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of MOTS-c and SS-31 — mechanism, dosing, side effects, legal status, and pricing.
MOTS-c is a 16-amino-acid mitochondrial-derived peptide (MDP) encoded within the mitochondrial 12S rRNA, discovered by Lee and Cohen at USC in 2015 (sequence: MRWQEMGYIFYPRKLR). It is an investigational, research-only peptide studied as a metabolic regulator; it has not been approved by the FDA for any indication.
SS-31 (elamipretide) is a mitochondria-targeted tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2) developed by Hazel Szeto (Cornell) and clinically advanced by Stealth BioTherapeutics. It concentrates in the inner mitochondrial membrane by binding cardiolipin. In September 2025, the FDA granted accelerated approval to elamipretide (brand name FORZINITY) as the first therapy for Barth syndrome — the first FDA-approved mitochondria-targeted drug. It remains investigational for other indications.
MOTS-c
SS-31
Category
Legal Status
Mechanism
Dose Range
Route
Frequency
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
MOTS-c
SS-31
COA corpus from Disclosed Labs — independently tested batches only.
MOTS-c
193
COAs
99.5%
Avg purity
16
Labs
SS-31
65
COAs
99.8%
Avg purity
12
Labs
Lee et al. (Cell Metabolism, 2015; PMID 25738459) identified MOTS-c and showed that exogenous administration in mice prevented diet-induced obesity and insulin resistance via AMPK activation in skeletal muscle. Kim et al. (Cell Metabolism, 2018; PMID 29983246) demonstrated that MOTS-c translocates to the nucleus under metabolic stress and regulates antioxidant response element (ARE) genes. Reynolds et al. (Nature Communications, 2021; PMID 33473109) reported that exercise induces MOTS-c in human skeletal muscle and that MOTS-c treatment improved physical capacity in young, middle-aged, and aged mice. Human clinical data are limited to CohBar's Phase 1a/1b study of the analog CB4211 in healthy volunteers and obese NAFLD subjects, which reported acceptable tolerability and exploratory signals on ALT/AST and glucose; CohBar wound down the program in 2023. No completed Phase 2 or Phase 3 trials exist for MOTS-c or its analogs, and grey-market dosing (typically ~10 mg SubQ 2-3x/week) is not clinically validated.
Key references
The original SS-peptide class was described by Zhao, Szeto and colleagues (J Biol Chem 2004, PMID 15178689), showing ~1000-fold concentration at the inner mitochondrial membrane and protection against oxidative cell death. Szeto's 2014 review (Br J Pharmacol, PMID 24117165) reframed the mechanism as cardiolipin-binding rather than antioxidant scavenging. The TAZPOWER trial (NCT03098797) in Barth syndrome, with its 168-week open-label extension (Thompson et al., Genet Med 2024, PMID 38602181), supported FDA accelerated approval of FORZINITY in September 2025 at 40 mg SubQ daily. The Phase 3 MMPOWER-3 trial in primary mitochondrial myopathy (Karaa et al., Neurology 2023, PMID 37268435) FAILED co-primary endpoints of 6-minute walk test and fatigue score, though a post-hoc nuclear-DNA subgroup showed improvement. Phase 2 ReCLAIM-2 in geographic atrophy missed primary endpoints but reduced ellipsoid-zone attenuation; a Phase 3 trial is ongoing. Earlier heart failure trials (PROGRESS-HF) showed only modest signals.
MOTS-c (Metabolic) and SS-31 (Recovery) are in different categories and target different biological pathways. This is a common pattern in multi-compound research protocols. Researchers should monitor the biomarkers from both profiles and watch for interactions listed in each compound’s contraindications. Consult a licensed healthcare provider before combining any research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Dosing Notes
Half-life
Side Effects
Contraindications
Lab Testing
Key references
Disclosed Labs