The Three Enemies of Peptide Integrity
Temperature, light, and humidity are the primary drivers of peptide degradation. Controlling these three variables is the simplest and most effective way to protect your research compounds — yet improper storage remains the most common cause of unexpected research results.
Temperature Guidelines
| Condition | Temperature | Duration | Use Case |
|---|---|---|---|
| Long-term lyophilized | -20°C (freezer) | 2+ years | Stock storage, unopened vials |
| Short-term lyophilized | 2-8°C (fridge) | 1-3 months | Vials in active rotation |
| Reconstituted | 2-8°C (fridge) | ≤4 weeks | Active research use |
| Active bench use | Room temperature | Minutes only | During reconstitution/aliquoting |
Critical Rule
Never freeze reconstituted peptides. Ice crystal formation disrupts peptide secondary structure and causes irreversible aggregation. If you need long-term storage of reconstituted peptide, aliquot into single-use portions and flash-freeze in dry ice.
Light Protection
UV radiation causes photodegradation of peptides, particularly those containing tryptophan (Trp), tyrosine (Tyr), or phenylalanine (Phe). These aromatic residues absorb UV light and undergo oxidative degradation.
- Store in amber vials whenever possible
- If using clear vials, wrap in aluminum foil
- Limit bench-top light exposure during reconstitution to under 15 minutes
- Store in a dark refrigerator section (not the door)
Humidity Control
Moisture is the silent destroyer of lyophilized peptides. Hygroscopic peptides absorb atmospheric water, initiating degradation pathways before you even reconstitute them.
- Store lyophilized vials with desiccant packets in sealed containers
- Never open vials in high-humidity environments (bathrooms, kitchens)
- Allow refrigerated vials to reach room temperature before opening (prevents condensation)
- GHK-Cu is especially hygroscopic — extra desiccant recommended
Per-Peptide Recommendations
- BPC-157: -20°C lyophilized (6+ months stable). 2-8°C reconstituted, 4 weeks. Relatively stable peptide.
- TB-500: -20°C recommended even short-term. More heat-sensitive than BPC-157.
- Semaglutide: 2-8°C preferred even lyophilized. Reconstituted: use within 28 days.
- Epitalon: -20°C, protected from light. Small tetrapeptide, moderate stability.
- GHK-Cu: -20°C with desiccant. Highly hygroscopic — extra moisture protection critical.
- Selank / Semax: -20°C. Reconstituted solutions less stable — use within 2-3 weeks.
Freeze-Thaw Protocol
If you absolutely must freeze reconstituted peptides:
- Aliquot into single-use portions first (never freeze the main vial)
- Flash-freeze by placing in dry ice bath for 5 minutes
- Transfer to -20°C freezer
- Thaw at 2-8°C (fridge), never at room temperature
- Each freeze-thaw cycle reduces potency by approximately 5-15%
For research purposes only.