Which has more human data?

Going by the research status on each profile (MOTS-c: Preclinical (animal); SS-31 (Elamipretide): FDA-approved), SS-31 (Elamipretide) is furthest along in human testing. Research status describes the stage of the published evidence, not whether a compound works or is safe.

What are the half-lives?

MOTS-c: Unknown. SS-31 (Elamipretide): No published PK data found (HFrEF 4-h IV infusion: peak at end-infusion, undetectable by 24 h). Figures are as reported in the cited studies, with the species where stated.

Are they FDA-approved?

MOTS-c: research status “Preclinical (animal)”. Not FDA-approved. Removed from 503A Category 2 on April 15, 2026. PCAC recommended for the 503A Bulks List (advisory); awaiting FDA rulemaking; not lawfully compoundable under 503A as of Sept 17, 2026. PCAC vote: 7–5–2 (yes–no–abstain), July 23, 2026. SS-31 (Elamipretide): research status “FDA-approved”. FDA-approved (accelerated approval, Sept 19 2025) for Barth syndrome only; any other use is off-label/investigational. See the FDA peptide regulatory tracker for sourced compounding status.

How are they administered in the research?

MOTS-c: Subcutaneous injection. SS-31 (Elamipretide): Subcutaneous or IV injection. This describes the published studies and is not a recommendation for human use.

How do their proposed mechanisms differ?

MOTS-c: In plain terms: It is a small peptide made by mitochondria that acts mainly on muscle energy use, based on mouse and cell studies. Proposed mechanism, from mouse and cell studies (Lee 2015): a mitochondrial-derived peptide whose primary target appears to be skeletal muscle; it inhibits the folate cycle and de novo purine biosynthesis, leading to AMPK activation. In mice it prevented age-dependent and high-fat-diet-induced insulin resistance and diet-induced obesity. SS-31 (Elamipretide): In plain terms: It targets a fat molecule inside mitochondria, the cell's power plants, and is approved for one rare disease (Barth syndrome). Targets cardiolipin in the inner mitochondrial membrane and is proposed to stabilize electron transport and reduce ROS production (mechanism review, Sabbah 2025). It received FDA accelerated approval for Barth syndrome, a disorder of cardiolipin remodelling (Zhao 2026). These are mechanisms proposed in the cited research, at the research stage listed for each compound.

MOTS-c vs SS-31 (Elamipretide): Research Comparison

Built from the MOTS-c, SS-31 (Elamipretide) research profiles · Profiles last updated October 1, 2026 · Reviewed by The Peptide Dispatch Editorial Team

TL;DR

This page compares MOTS-c and SS-31 (Elamipretide) using only their research-profile data. MOTS-c (research stage: Preclinical (animal); half-life: Not established in published research). It is a small peptide made by mitochondria that acts mainly on muscle energy use, based on mouse and cell studies. SS-31 (Elamipretide) (research stage: FDA-approved; half-life: Not established in published research). It targets a fat molecule inside mitochondria, the cell's power plants, and is approved for one rare disease (Barth syndrome). Educational summary, not medical advice.

Where each point comes from: Clinicalhuman trials and FDA labels Lab / animalrodent, cell and ex vivo studies Community-reporteduser experience and commonly used protocols, not from clinical studies

Educational summary. Everything below is taken from each compound's research profile and describes what was reported in the cited studies — not a promise of results, a dose recommendation, or an endorsement for human use. Not medical advice. Full disclaimer.

Side-by-side comparison

	MOTS-c	SS-31 (Elamipretide)
Category	Metabolic	Anti-Aging
Research status	Preclinical (animal)	FDA-approved
Regulatory note (as of Sept 2026)	Not FDA-approved. Removed from 503A Category 2 on April 15, 2026. PCAC recommended for the 503A Bulks List (advisory); awaiting FDA rulemaking; not lawfully compoundable under 503A as of Sept 17, 2026. PCAC vote: 7–5–2 (yes–no–abstain), July 23, 2026. Regulatory tracker →	FDA-approved (accelerated approval, Sept 19 2025) for Barth syndrome only; any other use is off-label/investigational. Regulatory tracker →
Half-life	Unknown	No published PK data found (HFrEF 4-h IV infusion: peak at end-infusion, undetectable by 24 h)
Administration route	Subcutaneous injection	Subcutaneous or IV injection
Dosing used in published research (not a recommendation)	i.p. injection in mice fed high-fat diet and aged mice (Lee et al. 2015); exact mg/kg in full text, not in abstract	HFrEF: single 4-h IV infusion 0.005, 0.05, 0.25 mg/kg/h; Barth syndrome (TAZPOWER): daily SC injection.
Community-reported protocol (not from clinical studies)	Community-reported5–10 mg weekly, subcutaneous injection	Community-reported0.25–4 mg/kg, subcutaneous or IV injection
How it works (as summarized from the cited research)	In plain terms: It is a small peptide made by mitochondria that acts mainly on muscle energy use, based on mouse and cell studies. Proposed mechanism, from mouse and cell studies (Lee 2015): a mitochondrial-derived peptide whose primary target appears to be skeletal muscle; it inhibits the folate cycle and de novo purine biosynthesis, leading to AMPK activation. In mice it prevented age-dependent and high-fat-diet-induced insulin resistance and diet-induced obesity.	In plain terms: It targets a fat molecule inside mitochondria, the cell's power plants, and is approved for one rare disease (Barth syndrome). Targets cardiolipin in the inner mitochondrial membrane and is proposed to stabilize electron transport and reduce ROS production (mechanism review, Sabbah 2025). It received FDA accelerated approval for Barth syndrome, a disorder of cardiolipin remodelling (Zhao 2026).
Effects reported in research (study subjects as stated)	Lab / animalIn animal studies: metabolic regulation Lab / animalExercise-mimetic effects in mouse studies Lab / animalPrevented diet-induced obesity and insulin resistance in mice	ClinicalIn a drug review: described as the first cardiolipin-directed mitochondrial therapeutic, approved under accelerated approval for Barth syndrome (Zhao 2026) ClinicalIn a Barth syndrome RCT, no significant 6MWT improvement; benefits seen in open-label extension. In an HFrEF RCT (n=36), a single infusion reduced LV volumes.
Potential side effects	No published human safety data for exogenous MOTS-c	ClinicalInjection-site reactions (most common, mild, in Barth syndrome trials) No serious AEs in single-dose HFrEF study (n=24 active)
Profile description	Mitochondria-derived peptide that regulates metabolic homeostasis; in mice it prevented diet-induced obesity and insulin resistance.	Mitochondria-targeted tetrapeptide that improves mitochondrial function and reduces oxidative stress. FDA-approved (accelerated) for Barth syndrome; investigated in heart failure and other mitochondrial diseases.
References cited on the profile	2	4

Key differences in the published research

Research status: MOTS-c — Preclinical (animal); SS-31 (Elamipretide) — FDA-approved.
FDA approval: only SS-31 (Elamipretide) carries an “FDA-approved” research status.
Category: MOTS-c — Metabolic; SS-31 (Elamipretide) — Anti-Aging.
Reported half-life: MOTS-c — Unknown; SS-31 (Elamipretide) — No published PK data found (HFrEF 4-h IV infusion: peak at end-infusion, undetectable by 24 h).
Administration route in the literature: MOTS-c — Subcutaneous injection; SS-31 (Elamipretide) — Subcutaneous or IV injection.
Evidence cited: MOTS-c’s profile lists 2 references; SS-31 (Elamipretide)’s profile lists 4 references.

Regulatory status

MOTS-c: On the FDA peptide regulatory tracker: Removed from Category 2; PCAC recommended for the 503A Bulks List; awaiting FDA rulemaking. Details →
SS-31 (Elamipretide): On the FDA peptide regulatory tracker: FDA accelerated approval on Sept 19, 2025, for Barth syndrome. Details →

For the sourced, dated status of every peptide in FDA's 2026 compounding actions, see the FDA peptide regulatory tracker.

Frequently Asked Questions

Which has more human data?: Going by the research status on each profile (MOTS-c: Preclinical (animal); SS-31 (Elamipretide): FDA-approved), SS-31 (Elamipretide) is furthest along in human testing. Research status describes the stage of the published evidence, not whether a compound works or is safe.
What are the half-lives?: MOTS-c: Unknown. SS-31 (Elamipretide): No published PK data found (HFrEF 4-h IV infusion: peak at end-infusion, undetectable by 24 h). Figures are as reported in the cited studies, with the species where stated.
Are they FDA-approved?: MOTS-c: research status “Preclinical (animal)”. Not FDA-approved. Removed from 503A Category 2 on April 15, 2026. PCAC recommended for the 503A Bulks List (advisory); awaiting FDA rulemaking; not lawfully compoundable under 503A as of Sept 17, 2026. PCAC vote: 7–5–2 (yes–no–abstain), July 23, 2026. SS-31 (Elamipretide): research status “FDA-approved”. FDA-approved (accelerated approval, Sept 19 2025) for Barth syndrome only; any other use is off-label/investigational. See the FDA peptide regulatory tracker for sourced compounding status.
How are they administered in the research?: MOTS-c: Subcutaneous injection. SS-31 (Elamipretide): Subcutaneous or IV injection. This describes the published studies and is not a recommendation for human use.
How do their proposed mechanisms differ?: MOTS-c: In plain terms: It is a small peptide made by mitochondria that acts mainly on muscle energy use, based on mouse and cell studies. Proposed mechanism, from mouse and cell studies (Lee 2015): a mitochondrial-derived peptide whose primary target appears to be skeletal muscle; it inhibits the folate cycle and de novo purine biosynthesis, leading to AMPK activation. In mice it prevented age-dependent and high-fat-diet-induced insulin resistance and diet-induced obesity. SS-31 (Elamipretide): In plain terms: It targets a fat molecule inside mitochondria, the cell's power plants, and is approved for one rare disease (Barth syndrome). Targets cardiolipin in the inner mitochondrial membrane and is proposed to stabilize electron transport and reduce ROS production (mechanism review, Sabbah 2025). It received FDA accelerated approval for Barth syndrome, a disorder of cardiolipin remodelling (Zhao 2026). These are mechanisms proposed in the cited research, at the research stage listed for each compound.

References

MOTS-c

The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance
Lee C, Zeng J, Drew BG, Sallam T, Martin-Montalvo A, Wan J et al. Cell metabolism. 2015. PMID: 25738459.
Study type: Mouse (HFD and aged) + cell studies.
DOI: 10.1016/j.cmet.2015.02.009 · PubMed
MOTS-c in type 2 diabetes mellitus: From risk factors to cardiac complications and potential treatment
Fang T, Han JC, Taberner A, Pham T. Life sciences. 2025. PMID: 41083123.
Study type: Review.
DOI: 10.1016/j.lfs.2025.124009 · PubMed

SS-31 (Elamipretide)

Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval
Zhao C, Zhuang X, Gao J. Drug discoveries & therapeutics. 2026. PMID: 41260682.
Study type: Regulatory/drug review.
DOI: 10.5582/ddt.2025.01111 · PubMed
Novel Mitochondria-Targeting Peptide in Heart Failure Treatment: A Randomized, Placebo-Controlled Trial of Elamipretide
Daubert MA, Yow E, Dunn G, Marchev S, Barnhart H, Douglas PS et al. Circulation. Heart failure. 2017. PMID: 29217757.
Study type: RCT n=36, HFrEF.
DOI: 10.1161/CIRCHEARTFAILURE.117.004389 · PubMed
Contemporary insights into elamipretide's mitochondrial mechanism of action and therapeutic effects
Sabbah HN, Alder NN, Sparagna GC, Bruce JE, Stauffer BL, Chao LH et al. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2025. PMID: 40294492.
Study type: Review.
DOI: 10.1016/j.biopha.2025.118056 · PubMed
Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study
Gwaltney C, Shields A, Love E, Ollis S, Stokes J, Mazar I et al. Orphanet journal of rare diseases. 2025. PMID: 40281531.
Study type: Phase 2 crossover RCT n=12 (TAZPOWER).
DOI: 10.1186/s13023-025-03693-5 · PubMed

Read the full profiles

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Educational content — not medical advice. Effects described are drawn from cited research in study subjects.

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