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Lyophilised vs Reconstituted SS-31: Different Storage Rules Apply
Lyophilised SS-31 arrives as a powder with residual moisture content below 3%. In this state, the peptide tolerates ambient temperature (20–25°C) for 2–3 weeks without significant degradation. Some manufacturers specify storage at −20°C for long-term stability
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- Lyophilised SS-31 arrives as a powder with residual moisture content below 3%. In this state, the peptide tolerates ambient temperature (20–25°C) for 2–3 weeks without significant degradation. Some manufacturers specify storage at −20°C for long-term stability (6+ months), but short-term room temperature exposure during shipping is generally acceptable. The absence of water prevents hydrolysis. Peptide bonds require aqueous environments to cleave. Lyophilised peptides degrade primarily through oxidation of aromatic residues, a process slowed dramatically by low moisture and temperature.
- Once you reconstitute SS-31 with bacteriostatic water (0.9% benzyl alcohol), the degradation profile shifts entirely. Water molecules now surround each peptide chain, enabling hydrolytic cleavage at amide bonds. The links between amino acids. The rate of hydrolysis follows Arrhenius kinetics: every 10°C increase in temperature roughly doubles the reaction rate. At 25°C (room temperature), reconstituted SS-31 loses approximately 15–20% potency within 7 days. At 37°C (body temperature if left in a warm car), degradation accelerates to 40–50% loss within 72 hours. At 2–8°C (refrigeration), degradation slows to 5–8% over 28 days. Acceptable for research use.
- Bacteriostatic water extends usability by preventing bacterial growth, not by stabilising the peptide. The 28-day use window reflects benzyl alcohol's antimicrobial efficacy, which degrades over time as the alcohol volatilises. After 28 days, bacterial contamination risk rises even if the peptide itself remains stable. For SS-31 specifically, oxidative degradation of the dimethyltyrosine residue typically becomes significant before the 28-day mark. Refrigeration slows but doesn't stop it. We've consistently observed that peptides stored beyond 21 days show reduced mitochondrial uptake in cellular assays, even when refrigerated properly.