Published · Aurelis Peptides
MOTS-C and SS-31 often appear together in conversations about cellular energy and ageing. Their studies ask different questions. Understanding that difference helps you read a paper, compare a catalogue entry and prepare a more precise enquiry.
This guide follows four primary research papers. Each finding stays connected to its setting: cultured cells, isolated mitochondria or mice. Start with the comparison table, then explore the observations behind each name.
What is the difference between MOTS-C and SS-31?
MOTS-C is a 16-amino-acid peptide encoded in mitochondrial DNA. The foundational study linked it to metabolic regulation. SS-31 is a synthetic four-amino-acid peptide studied for its interaction with cardiolipin, a lipid in the inner mitochondrial membrane. One research profile emphasises metabolic signalling. The other centres on the machinery that helps produce cellular energy. MOTS-C discovery study · SS-31 membrane study.
| Compare | MOTS-C | SS-31 |
|---|---|---|
| Research starting point | Mitochondrial-derived signalling peptide | Mitochondrial membrane-targeting peptide |
| Main themes in these papers | Fuel handling, insulin response and muscle adaptation | Cardiolipin, energy production and aged-muscle performance |
| Selected study settings | Cell experiments and mouse models | Isolated mitochondria and mouse models |
| Aurelis listed content | 40 mg per unit | 25 mg per unit |
| Read the full profile | MOTS-C catalogue entry | SS-31 catalogue entry |
MOTS-C: fuel handling and metabolic response
Lee and colleagues introduced MOTS-C in a 2015 study. Their cell experiments connected the peptide with changes in metabolic activity and activation of AMPK. AMPK helps cells respond to their energy state. That made energy sensing an important part of the MOTS-C research story.
The team also studied mice. They reported protection against insulin resistance linked to age and a high-fat diet. The high-fat-diet experiments also showed protection against diet-related weight gain. Those observations explain why MOTS-C appears in metabolism discussions. They describe the experimental mice and conditions used in that paper. Read Lee et al., 2015.
MOTS-C: muscle adaptation and physical capacity
A 2021 paper by Reynolds and colleagues explored physical performance in young, middle-aged and old mice. The researchers reported improved performance across those age groups. They also examined changes in skeletal-muscle metabolism and gene activity.
In cultured muscle precursor cells, the study examined adaptation to metabolic stress. The work brings muscle response and energy regulation into the same research profile. Physical capacity, cellular stress adaptation and metabolic measurements are distinct endpoints. Reading them separately gives a clearer picture of what the study tested. Read Reynolds et al., 2021.
SS-31: the inner mitochondrial membrane
The 2014 Birk study examined SS-31 and cardiolipin using laboratory membrane systems and mitochondrial preparations. Cardiolipin helps organise the inner mitochondrial membrane, where energy-production processes take place.
The researchers observed binding to cardiolipin-containing membranes. They also measured improved electron transfer under their experimental conditions. In fresh mitochondria, SS-31 increased respiration and the efficiency of ATP production. ATP is the energy-carrying molecule that cells use to power many activities. These measurements give the SS-31 profile its strong focus on mitochondrial function. Read Birk et al., 2014.
SS-31: energy measurements in aged muscle
Siegel and colleagues studied young and aged mice in 2013. Their measurements included mitochondrial ATP production and how efficiently energy production was coupled to oxygen use.
In the aged mice, the team reported improvements in those energy measurements. Aged muscle also showed greater resistance to fatigue, and a separate repeated-treatment experiment increased whole-animal endurance. Young muscle did not show the same observable response. Age and the starting condition of the muscle mattered in this experiment. Read Siegel et al., 2013.
How to compare the research
Begin with the question you want a paper to answer. For fuel handling and metabolic adaptation, start with the MOTS-C studies. For inner-membrane function and ATP production, start with the SS-31 studies.
The selected papers studied each peptide separately. They do not provide a direct head-to-head ranking. Compare the model, measured endpoint and control group before comparing headlines. A cell-metabolism result and a mouse-endurance result answer different questions, even when both sit under cellular energy.
MOTS-C 40 mg and SS-31 25 mg: reading the listings
Aurelis lists MOTS-C at 40 mg and SS-31 at 25 mg per unit. These are content specifications. The larger number does not indicate greater biological activity or a better result. The two entries identify different molecules.
Keep three details together when enquiring: the compound name, listed amount and required presentation. Ask for the selected material’s identity and content records so the documents match the entry you are discussing. Our quality guide explains the different questions answered by identity, purity and content testing.
Vials and kit presentations
Aurelis presents branded vials and pen-style kits across its format collection. A format enquiry should identify the specific peptide and the complete presentation you want to discuss. Confirm the format for that entry rather than assuming every compound comes in every pictured presentation.
Use the product-format guide to compare the information needed for a vial, cartridge or complete kit. Then open the MOTS-C profile or SS-31 profile, or send a focused comparison enquiry.
Primary research sources
- Lee et al. · Cell Metabolism · 2015 — MOTS-C discovery, cell metabolism and mouse metabolic experiments.
- Reynolds et al. · Nature Communications · 2021 — MOTS-C muscle response and mouse physical-capacity experiments.
- Birk et al. · British Journal of Pharmacology · 2014 — SS-31, cardiolipin and mitochondrial energy-production experiments.
- Siegel et al. · Aging Cell · 2013 — SS-31 energy measurements and muscle performance in aged mice.