# MOTS-c vs SS-31: How They Differ | PepVault

Source: https://pepvault.app/peptides/compare/mots-c-vs-ss-31

Last updated: 2026-10-12

[Library](https://pepvault.app/peptides) [Comparisons](https://pepvault.app/peptides/compare) MOTS-c vs SS-31

Compared side by side

# MOTS-c vs SS-31: how they differ

Reviewed October 2026 [How we check the library](https://pepvault.app/about#library)

## The short answer

Both work on mitochondria, from different sides: MOTS-c is a peptide encoded by mitochondrial DNA that, in mice, activates AMPK, the pathway exercise triggers; SS-31 binds cardiolipin in the inner mitochondrial membrane and, in cell and animal studies, cuts oxidative stress. SS-31 is FDA-approved as elamipretide (Forzinity) for the rare disease Barth syndrome. MOTS-c is taken 2–3 times a week, SS-31 daily.

## Side by side

| Compared | [MOTS-c](https://pepvault.app/peptides/mots-c) | [SS-31](https://pepvault.app/peptides/ss-31) |
| --- | --- | --- |
| Category | Longevity | Longevity |
| Also known as | Mitochondrial Open Reading Frame of the 12S rRNA-c | Elamipretide, Szeto-Schiller 31, MTP-131 |
| What it is | A peptide encoded by your mitochondrial DNA, the energy-producing organelles inside every cell. | A mitochondria-targeting peptide that binds directly to cardiolipin — a key lipid in the inner mitochondrial membrane where your cells generate energy. |
| How it works | Mitochondria-derived peptide that regulates metabolic homeostasis. In mouse and cell studies it activates the AMPK pathway, improves insulin sensitivity and exercise capacity, and slows some signs of aging. | Mitochondria-targeting peptide that binds cardiolipin in the inner mitochondrial membrane. Improves mitochondrial function and reduces oxidative stress (cell and animal studies). FDA-approved in 2025 (accelerated) for Barth syndrome, and in trials for dry AMD. |
| Commonly reported | More energy and better workout endurance over the first weeks, sometimes after a week or two of feeling tired. No human trial has tested it yet. | Injection-site redness, itching or welts (very common), and for some, steadier stamina with less post-exertion crash over weeks. |
| Studied range | Research range: 5–10 mg. Studied in research — not a recommendation. | Research range: 2–4 mg. Studied in research — not a recommendation. FDA-approved as Forzinity (elamipretide): 40 mg SubQ once daily, to improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kg (accelerated approval). |
| How often | 2–3× weekly | Daily |
| Half-life | Hours (short) | Short (hours) |
| Route | SubQ injection, IM injection | SubQ injection |
| Typical run | 4–8 week cycles common, 2–3× per year. Common splits: Mon/Thu (2× weekly) or Mon/Wed/Fri (3× weekly). Limited long-term human data — none on continuous dosing. | Daily or EOD use. Cycles of 4–8 weeks common; some run continuously. The Forzinity label doses it once daily with no break. |
| Evidence | Emerging: primarily preclinical / limited human data | Emerging: primarily preclinical / limited human data |
| Common side effects | Injection site reaction, mild fatigue first week | Injection site reaction, nausea, mild headache |

Typical run: Community practice — opinions vary. Not a clinical recommendation.

## Week by week

Each entry’s cards by day window, as the compound pages show them. Day 1 is the day you start it.

### MOTS-c

- Day 1–14 The first two weeks
- Day 14–28 Workouts often feel easier
- Day 28–56 Weeks 4 to 8: check your markers
- Day 56–84 Diminishing returns + cycle point

[Every card for MOTS-c, with its sources](https://pepvault.app/peptides/mots-c#weeks)

### SS-31

- Day 1–14 A slow, cumulative start
- Day 14–56 Where stamina changes show up
- Day 56–112 Maintenance or cycle-off

[Every card for SS-31, with its sources](https://pepvault.app/peptides/ss-31#weeks)

## Together or one or the other

MOTS-c and SS-31 are a common stack: each lists the other among its common stacks, and they’re together in the Longevity Core stack.

- **Longevity Core**: Mitochondrial health & cellular-aging stack (MOTS-c, Epitalon and SS-31).

Community · SS-31

### Full-spectrum mitochondrial stack

SS-31 protects the mitochondrial membrane itself, MOTS-c tunes metabolic signaling and humanin damps cell-death signaling. Three angles, one organelle. Rationale-based rather than trial-based — no combination data exists.

## Questions people ask

### How long do MOTS-c and SS-31 last?

The half-life of MOTS-c is hours (short). The half-life of SS-31 is short (hours).

### How often are MOTS-c and SS-31 taken?

MOTS-c: 2–3× weekly. Routes: SubQ injection, IM injection. SS-31: daily. Route: SubQ injection.

### How are MOTS-c and SS-31 dosed in research?

The research range for MOTS-c is 5–10 mg. Studied in research — not a recommendation. The research range for SS-31 is 2–4 mg. Studied in research — not a recommendation. FDA-approved as Forzinity (elamipretide): 40 mg SubQ once daily, to improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kg (accelerated approval).

### What are the common side effects of MOTS-c and SS-31?

For MOTS-c, the library lists: injection site reaction, mild fatigue first week. For SS-31: injection site reaction, nausea, mild headache.

### Are MOTS-c and SS-31 taken together?

MOTS-c and SS-31 are a common stack: each lists the other among its common stacks, and they’re together in the Longevity Core stack. SS-31 protects the mitochondrial membrane itself, MOTS-c tunes metabolic signaling and humanin damps cell-death signaling. Three angles, one organelle. Rationale-based rather than trial-based — no combination data exists.

## Each one in full

- [MOTS-c: dosage, half-life & reference guide](https://pepvault.app/peptides/mots-c)
- [SS-31: dosage, half-life & reference guide](https://pepvault.app/peptides/ss-31)
- [MOTS-c dose guide](https://pepvault.app/lab/dosage/mots-c)
- [SS-31 dose guide](https://pepvault.app/lab/dosage/ss-31)

PepVault for iPhone

## Track either one in PepVault

Log every dose of MOTS-c or SS-31, with reminders on your schedule. 7 days free on the yearly plan for new subscribers.

[Download on the App Store](https://apps.apple.com/app/apple-store/id6779318649?pt=129020030&ct=compound-vs-band&mt=8)

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## The library

- [The peptide reference library](https://pepvault.app/peptides)
- [Longevity peptides](https://pepvault.app/peptides#longevity)

## Free tools

- [The Dose Guide](https://pepvault.app/lab/dosage)
- [Half-life & active level](https://pepvault.app/tools/peptide-half-life-calculator)
- [Reconstitution calculator](https://pepvault.app/tools/reconstitution-calculator)

PepVault is a research and tracking resource, not medical advice. Ranges are what studies used, never a dose for you. Brand names are trademarks of their owners; PepVault is independent of them.

PepVault is a private research and tracking tool, not medical advice. The information here is reference material from published literature and community use — always verify it and discuss any protocol with a qualified clinician before changing it.

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