Skip to content
Peptides Codex
ENFR

Use the arrow keys to choose a result, Enter to open it, and Escape to close.

← Home
Research / clinical peptide

SS-31

SS-31 (elamipretide) is a mitochondria-targeting tetrapeptide studied for effects on mitochondrial membranes and bioenergetics in experimental and clinical research programs.

By The Peptides Codex Editorial TeamIndividual review date not recorded

Page data last changed: . Chemistry registry snapshot: . Registry refreshes and identity assessments are separate from scientific content review.

Length
4 aa
Class
Research / clinical peptide
Function
Mitochondria-targeted tetrapeptide
Context
Clinical development history for mitochondrial/cardiac indications; research use

Mitochondrial peptide pharmacology — premium educational niche.

Also known as: elamipretide · bendavia · MTP-131

Part of the Foundational & therapeutic peptides cluster

Overview

SS-31 (elamipretide) is a mitochondria-targeting tetrapeptide studied for effects on mitochondrial membranes and bioenergetics in experimental and clinical research programs.

Source & context

Biological / chemical source: Synthetic aromatic-cationic tetrapeptide

Primary research or clinical context: Clinical development history for mitochondrial/cardiac indications; research use

Targeting mitochondria

SS-31 associates with cardiolipin-rich inner mitochondrial membranes in research models — a distinct localization story compared with circulating hormone peptides.

Sequence

One-letter sequence commonly cited for SS-31 (educational; isoforms and modifications may differ):

RXKF

RXKF

X = non-canonical or modified residue in the IUPHAR record. X marks a non-canonical residue — see the structure block below. (Plotted as alanine on the wheel.)

SS-314 aa · C32H49N9O5 · ≈ 639.8 DaPEPTIDESCODEX.COMN-terminus →→ C-terminusR+1X2K+3F4nonpolarpolaracidicbasicGly / Pronon-canonical (X)Hydropathy (Kyte–Doolittle): ▮ hydrophobic (cyan) / ▮ hydrophilic (rose) · Side-chain charge at pH 7: + / −X = non-canonical or modified residue in the IUPHAR record
SS-31 — Structure cardDownload SVG
R1A2K3F4
Helical wheel projection

Residues plotted ~100° apart around an α-helix — clustering of one color reveals an amphipathic face.

Analyze sequences in the playground →

Structure & chemistry

Molecular identity & reference confidence

Source-supported reference

Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.

Molecular form
SS-31 (source record; form not independently established)
Species
Not established by this molecular identity audit
Termini (N / C)
Not specified / Not specified

Average reference mass

Reference policy updated: 2026-10-05

Molecular formula
C32H49N9O5
Average reference mass
≈ 639.8
Status
Approved medicine in at least one jurisdiction (IUPHAR record)
Identifiers

Chemistry values: IUPHAR/BPS Guide to Pharmacology, PubChem · fetched 2026-10-01.

Clinical development snapshot

ClinicalTrials.gov lists 1 registered study with “SS-31” as an intervention (snapshot 2026-09-06). A registry footprint is not evidence of efficacy or approval.

Registered studies
1
Highest phase reached
Phase 2
Active in latest 100
0
Most recent update
2025-12-12
Most recently updated studies
NCTTitlePhaseStatusUpdated
NCT05168774FRDA Investigator Initiated Study (IIS) With ElamipretidePhase 2completed2025-12-12
See all on ClinicalTrials.gov →
Concentration math

SS-31 — reconstitution calculator

Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.

Reference form: SS-31 (source record; form not independently established)Average reference mass: 639.8 Da

Syringe graduation
Solution concentration
5 mg/mL5,000 mcg/mL
mcg

Enter an amount to see the volume it corresponds to.

Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.

Open the SS-31 calculator on its own page →

FAQ about SS-31

What is SS-31?+

SS-31 (elamipretide) is a mitochondria-targeting tetrapeptide studied for effects on mitochondrial membranes and bioenergetics in experimental and clinical research programs.

What Canadian product status is recorded for SS-31?+

Canadian product status for SS-31 has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.

What is the typical length of SS-31?+

SS-31 is commonly described as approximately 4 amino acids (Research / clinical peptide).

Related peptides

Insulin
Hormone
Insulin is a 51-amino-acid peptide hormone that regulates blood glucose. It is the foundational peptide therapeutic and a reference point for modern peptide drug design.
Bremelanotide (PT-141)
Cyclic melanocortin-receptor agonist (approved medicine)
Bremelanotide, developed as PT-141, is a cyclic seven-residue analogue of α-melanocyte-stimulating hormone that activates melanocortin receptors, with its effect on sexual desire attributed to MC3 and MC4 signalling in the brain. The FDA approved it in 2019 as Vyleesi, an on-demand subcutaneous autoinjector for premenopausal women with acquired, generalised hypoactive sexual desire disorder. Nausea occurred in 40% of phase 3 participants, and a 2024 reanalysis found effect sizes from nil to small on most trial outcomes.
GHK-Cu
Cosmetic / research peptide
GHK-Cu is the copper(II) complex of glycyl-L-histidyl-L-lysine, a tripeptide found in human plasma at about 200 ng/mL at age 20 and 80 ng/mL by 60. It has a wide cell and animal literature on collagen synthesis, wound repair and anti-inflammatory signalling, a cosmetic market built on it, and — as a 2025 review notes — a surprising absence of clinical studies. Topical use is permitted as a cosmetic; it is not an approved drug.
MOTS-c
Mitochondrial-derived peptide (research compound)
MOTS-c is a 16-amino-acid peptide (MRWQEMGYIFYPRKLR; C101H152N28O22S2, ≈2,175 Da) encoded by a short open reading frame inside the mitochondrial 12S rRNA gene. Discovered in 2015, it promoted metabolic homeostasis and reduced obesity and insulin resistance in mice, and translocates to the nucleus under metabolic stress to regulate nuclear genes. Plasma levels decline with age. It is a research compound with no approval; its first phase 2 trial, in prediabetes, was recruiting in 2026.

References & further reading

  1. 1.Pharaoh et al. (2023). The mitochondrially targeted peptide elamipretide (SS-31) improves ADP sensitivity in aged mitochondria by increasing uptake through the adenine nucleotide translocator (ANT). Geroscience
  2. 2.Shirley (2026). Elamipretide: First Approval. Drugs
  3. 3.Tung et al. (2025). Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Potential. Int J Mol Sci
  4. 4.Zhao et al. (2019). Elamipretide (SS-31) improves mitochondrial dysfunction, synaptic and memory impairment induced by lipopolysaccharide in mice. J Neuroinflammation
  5. 5.Obi et al. (2022). Targeting mitochondrial dysfunction with elamipretide. Heart Fail Rev
  6. 6.Jacob et al. (2025). Elamipretide in the Management of Barth Syndrome: Current Evidence and a Case Report. Mol Genet Metab
  7. 7.Karaa et al. (2023). Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial. Neurology
  8. 8.Karaa et al. (2024). Genotype-specific effects of elamipretide in patients with primary mitochondrial myopathy: a post hoc analysis of the MMPOWER-3 trial. Orphanet J Rare Dis
  9. 9.PubChem — compound summary for Elamipretide / SS-31 (CID 11764719)
  10. 10.Wikipedia — Elamipretide
Disclaimer: Educational content only. Not medical advice. Not instructions for human use. Research peptides and unapproved products may be restricted or illegal to market for human consumption in your jurisdiction. Consult qualified professionals and applicable law.
You might also like: All peptides · Atlas · Research · Tools
Cite this: Peptides Codex — SS-31 educational profile.
Tip: Use browser print (Ctrl/Cmd + P) for a clean PDF of this page.