This page compares what is documented about MOTS-c (Human) and SS-31, rather than ranking them by effect. What each molecule is, the sizes and prices actually carried, what the certificate covers, and how the two differ on the bench. Everything here is research-use-only material and we do not publish outcome, dosing or administration content for any compound in the catalogue.
What is MOTS-c (Human) and what is SS-31?
MOTS-c (Human). MOTS-c is encoded inside the mitochondrial 12S rRNA gene — a mitochondrial-derived peptide studied in metabolic-signalling and exercise-biology models since 2015.
SS-31. SS-31 (elamipretide's research form) concentrates in the inner mitochondrial membrane by binding cardiolipin — one of the few peptides with a genuinely novel targeting mechanism.
How do MOTS-c (Human) and SS-31 compare on price and size?
| MOTS-c (Human) | SS-31 | |
|---|---|---|
| Sizes carried | 10 mg, 20 mg, 40 mg | 10 mg, 50 mg |
| From | $60.00 | $59.00 |
| Best price per unit | $2.50 / mg | $4.18 / mg |
| Availability | Backordered — waitlist | Backordered — waitlist |
| Certificate | Lot certificate on the product page | Lot certificate on the product page |
| Molecular formula | C101H152N28O22S2 | C32H49N9O5 |
| Molar mass | 2,174.6 g/mol | 639.8 g/mol |
| Source | PubChem CID 146675088 | PubChem CID 11764719 |
| Research area | mitochondrial-signalling research | mitochondrial-membrane research |
At their best sizes MOTS-c (Human) works out at $2.50 per mg against $4.18 for SS-31 — 67% more for the mg. Vial prices start at $60.00 and $59.00 respectively, which is the number most people compare and the one that says least, because the two are not sold in the same sizes. Full sizes, tier pricing and the lot certificate sit on the MOTS-c (Human) page and the SS-31 page.
What is each one studied for?
What the published literature investigates, which is a different question from what either will do, and the only one of the two a supplier can answer.
MOTS-c (Human) is studied in mitochondrial-signalling research. Mitochondrial-derived peptides are a young and fast-moving corner of metabolic research, with MOTS-c the most-studied of the family.
SS-31 is studied in mitochondrial-membrane research. Mitochondrial-membrane research continues to build around cardiolipin biology, where SS-31 remains the reference targeting peptide.
Studied in the same area does not make two compounds interchangeable, and the research library holds the per-compound documentation.
SS-31 vs MOTS-c (Human): how they differ on the bench
SS-31. SS-31's aromatic-cationic structure makes it robust in solution compared with most peptides — but the same structure demands LC-MS to distinguish it from close analogues.
MOTS-c (Human). MOTS-c is a 16-residue peptide with a critical central motif; sequence-level identity confirmation matters more here than for longer, more forgiving chains.
What actually differs between SS-31 and MOTS-c (Human)
Worth doing the arithmetic before comparing sizes: MOTS-c (Human) is 2,174.6 g/mol and SS-31 is 639.8 g/mol, a factor of 3.4. A milligram of SS-31 therefore contains roughly 3.4 times as many molecules as a milligram of MOTS-c (Human), so two vials of the same labelled mass hold quite different amounts of substance. Equal milligrams are not equal moles, which is what the molarity calculator exists to convert, and it is the reason a price-per-milligram comparison and a price-per-mole comparison can point at different vials.
Identity is the other analytical axis, and it is settled per lot rather than per compound. MOTS-c (Human). Catalogued as MOTS-c, and the certificate's identity test resolves to that. SS-31. Catalogued as Elamipretide, and the certificate's identity test resolves to that.
Both are released against a certificate reporting identity, purity by the stated method and net peptide content, readable before anything is bought.
Which is better, SS-31 or MOTS-c (Human)?
Neither SS-31 nor MOTS-c (Human) is ranked against the other here, and the refusal is deliberate. Better, safer and stronger are questions about effects in a living system, and we sell neither compound for use in one — why none of these pages ranks two compounds sets out the reasoning in full.
What it does instead, for these two:
- MOTS-c (Human) is the cheaper of the two per mg, at $2.50 against $4.18.
- MOTS-c (Human) is the heavier molecule by a factor of 3.4, so equal milligrams are not equal moles.
- MOTS-c (Human) is carried in 3 sizes and SS-31 in 2, and each lot carries its own certificate.
Every one of those is checkable before you buy.
Common questions
What is the difference between SS-31 and MOTS-c (Human)?
Different molecules before anything else: SS-31 is C32H49N9O5 and MOTS-c (Human) is C101H152N28O22S2. SS-31 (elamipretide's research form) concentrates in the inner mitochondrial membrane by binding cardiolipin — one of the few peptides with a genuinely novel targeting mechanism. MOTS-c is encoded inside the mitochondrial 12S rRNA gene — a mitochondrial-derived peptide studied in metabolic-signalling and exercise-biology models since 2015.
Which one should I choose?
MOTS-c (Human) is carried in 10 mg, 20 mg, 40 mg and SS-31 in 10 mg, 50 mg, each lot with its own certificate. Which of those suits the work is yours to decide; everything here is research-use-only rather than guidance for use in a human or an animal.
Do both MOTS-c (Human) and SS-31 come with a certificate of analysis?
Neither is in stock at the moment, so in each case the certificate is the one attached to the lot that arrives. A certificate belongs to a lot, not to a product. It is linked from the product page, and reports identity, purity by the stated method, and net peptide content for the material actually in that lot.
Which is cheaper, SS-31 or MOTS-c (Human)?
Per mg, MOTS-c (Human) at $2.50 against $4.18, taking each one's best size. By vial they start at $60.00 for MOTS-c (Human) and $59.00 for SS-31, which is the comparison most people make and the one that says least, because the two are not sold in the same sizes.
Is a milligram of MOTS-c (Human) the same as a milligram of SS-31?
By mass yes, by amount of substance no. MOTS-c (Human) is 2,174.6 g/mol and SS-31 is 639.8 g/mol, a factor of 3.4, so a milligram of SS-31 holds roughly 3.4 times as many molecules. Two vials with the same number on the label are not the same amount of substance, which is what the molarity calculator converts.
FOR LABORATORY AND IN-VITRO RESEARCH USE ONLY. NOT FOR HUMAN OR ANIMAL CONSUMPTION. NOT FOR PERSONAL, MEDICAL, DIAGNOSTIC, THERAPEUTIC, OR RECREATIONAL USE.