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SS-31 Chemical Structure: Sequence, Formula, Mass | Palmetto Peptides

The Chemical Structure of SS-31 Research Peptide: Sequence, Molecular Formula, and Molecular Weight Explained Research Notice: This article covers research on SS-31 research peptide and MOTS-C research peptide — available from Palmetto Peptides for laboratory

By Recovery & Performance Peptides Editorial Team Published June 29, 2026

The Chemical Structure of SS-31 Research Peptide: Sequence, Molecular Formula, and Molecular Weight Explained

Research Notice: This article covers research on SS-31 research peptide and MOTS-C research peptide — available from Palmetto Peptides for laboratory use only.

Research Use Only Disclaimer: All peptides listed on this page are sold exclusively for in vitro and legitimate laboratory research purposes. They are not intended for human consumption, veterinary use, or any clinical application. The information in this article is for scientific and educational reference only and does not constitute medical advice. All research use must comply with applicable federal, state, and institutional regulations. Palmetto Peptides complies fully with all applicable FDA guidelines.

Research Disclaimer: SS-31 is sold by Palmetto Peptides strictly as a research compound for in vitro and laboratory use only. It is not intended for human or veterinary consumption, administration, or therapeutic use.

For a complete overview of this research area, see the Complete Guide to SS-31 (Elamipretide) Research Peptide from Palmetto Peptides.

SS-31 is a tetrapeptide research compound with the sequence D-Arg-Dmt-Lys-Phe-NH2, molecular formula C32H49N9O5, and molecular weight approximately 639.80 g/mol. Researchers can order SS-31 research peptide from Palmetto Peptides with full lot-specific COA documentation for mitochondrial laboratory studies.

Last Updated: April 21, 2026 | Reading Time: Approximately 2 minutes | Author: Palmetto Peptides Research Team

Quick Answer

The SS-31 Amino Acid Sequence, Position by Position

Position 1: D-Arginine (D-Arg)

The D-form of arginine contributes a positive charge at physiological pH via its guanidinium side chain. The D-configuration provides resistance to proteolytic degradation in cell-based assay work — a practical advantage over standard L-peptides.

Position 2: 2',6'-Dimethyltyrosine (Dmt)

A synthetic non-proteinogenic amino acid derived from tyrosine with two methyl groups added to the aromatic ring. This increases lipophilicity and membrane affinity, and is central to the cardiolipin-binding behavior studied in mitochondrial research. Researchers exploring related mitochondrial science may also find MOTS-C mitochondrial peptide research and mitochondrial function research relevant.

Researchers seeking a broader review can consult the Complete Guide to SS-31 (Elamipretide) Research Peptide, which covers the full research landscape in detail.

Position 3: Lysine (Lys)

Standard L-lysine contributes a positive charge at physiological pH, completing the alternating aromatic-cationic motif that defines the Szeto-Schiller family.

Position 4: Phenylalanine-NH2 (Phe-NH2)

The C-terminal amide cap eliminates the negative charge at the terminus, resulting in net charge approximately +3 at physiological pH.

Molecular Formula and Molecular Weight Reference

Molecular Formula

C32H49N9O5

Molecular Weight

~639.80 g/mol

Net Charge (pH 7.4)

CAS Number

736992-21-5

Also Known As

Elamipretide, MTP-131, Bendavia

Why This Formula Matters in Laboratory Research

The formula C32H49N9O5 is the foundation for mass spectrometry identity verification. The nitrogen-rich composition (9 nitrogen atoms) reflects the multiple guanidinium and amino groups driving the positive charge. For additional context: NAD+ research peptide science and cellular health research. Order SS-31 research peptide here.

Frequently Asked Questions

What is the amino acid sequence of SS-31?

D-Arg-Dmt-Lys-Phe-NH2, where Dmt is 2',6'-dimethyltyrosine.

What is the molecular formula of SS-31?

C32H49N9O5, molecular weight approximately 639.80 g/mol.

Is SS-31 approved for human use?

No. SS-31 has not received FDA approval. It is available exclusively as a research compound for qualified laboratory settings.

See Also: SS-31 Research Peptide: Complete Guide

Related Research

Analytical Methods for Verifying SS-31 Research Peptide Identity and Purity in the Lab

Buying Guide: How to Select High-Quality SS-31 Research Peptide from Reputable Lab Suppliers

History and Development of Szeto-Schiller SS Peptides: The Research Origins of SS-31

CONNECTED / MODULES

Post-session references

Selected from shared article topics. Source links are retained where available.

COACH'S BOARD / KEY POINTS

SS-31 lyophilized powder must be stored at −20°C minimum (−80°C preferred) with twice-daily temperature logging to detect freezer failures before peptide degrades.
Reconstituted SS-31 remains stable for 28 days maximum at 2–8°C. The stability clock starts at reconstitution, not first use, and exceeding this window risks bacterial contamination even with bacteriostatic water.
Every freeze-thaw cycle reduces peptide bioactivity incrementally; aliquot SS-31 into single-use volumes immediately upon reconstitution and never refreeze thawed peptide.
pH drift below 6.0 or above 7.5 accelerates SS-31 aggregation. Include pH verification in your documentation at reconstitution and midpoint if the vial remains in use beyond 14 days.
Regulatory audits reject studies not for protocol deviations but for failure to document them. Your SS-31 research log track document must include a deviation log with timestamps, corrective actions, and investigator signatures.

SOURCE / realpeptides.co ↗

Handling & safety lane

Source-derived education, not individual medical guidance or an instruction to dose.

STORAGE

pH Effects on SS-31 Stability

At physiological pH (7.0-7.4), SS-31 maintains its full +3 charge. SS-31 is most stable in slightly acidic to neutral solutions (pH 4-7.5). At strongly alkaline pH above 8.5-9, base-catalyzed degradation and Dmt phenolate formation risks increase. Recommended pH range for SS-31 solutions: 4.0-7.5.

Evidence cooldown

Research context and source excerpts for a slower second read.

RESEARCH

Analytical Methods for Verifying SS-31 Research Peptide Identity and Purity in the Lab

Research Notice: This article covers research on SS-31 research peptide and MOTS-C research peptide — available from Palmetto Peptides for laboratory use only. Research Use Only Disclaimer: All peptides listed on this page are sold exclusively for in vitro and legitimate laboratory research purposes. They are not intended for human consumption, veterinary use, or any clinical application. The information in this article is for scientific and educational reference only and does not constitute medical advice. All research use must comply with applicable federal, state, and institutional regulations. Palmetto Peptides complies fully with all applicable FDA guidelines. Research Disclaimer: SS-31 is sold by Palmetto Peptides strictly as a research compound for in vitro and laboratory use only. For a complete overview of this research area, see the Complete Guide to SS-31 (Elamipretide) Research Peptide from Palmetto Peptides. Even when purchasing SS-31 from a reputable supplier with full COA documentation, some research contexts call for in-house analytical verification. Researchers can order SS-31 research peptide from Palmetto Peptides — where every lot provides baseline COA data for comparison. Related: BPC-157 quality and testing research and NAD+ analytical research. Last Updated: April 21, 2026 | Reading Time: Approximately 2 minutes | Author: Palmetto Peptides Research Team

RESEARCH

Complete SS-31 Research Cluster: All Supporting Articles

Chemical Structure: Sequence, Formula, Molecular Weight Structural chemistry reference Cardiolipin Interactions: What Lab Models Show Mechanism deep-dive In Vitro Mitochondrial Function Assays Assay design and protocols Reconstitution and Long-Term Storage Protocols Lab handling procedures SS-31 vs Other Szeto-Schiller Peptides Analog comparison HPLC Purity and Quality Control Standards COA interpretation Synthesis and Manufacturing Processes Production overview Solubility, Stability, and Buffer Formulation Formulation guidance History and Development of SS Peptides Research origins Buying Guide: Selecting a Reputable Supplier Purchasing guidance Analytical Methods for Identity and Purity Verification In-lab QC methods SS-31 FAQ for Scientists Common questions answered

Product & matchup locker

Linked catalog and comparison files.

Comparison

SS-31 vs Other Mitochondria-Targeted Research Compounds

MitoQ and SkQ1 use a triphenylphosphonium scaffold without defined cardiolipin binding — making SS-31 a distinct mechanistic tool for inner membrane research. See also: NAD+ resea…