Proper peptide storage is critical to preserving potency. A vial of BPC-157 stored incorrectly can lose 20-50% of its activity. This guide covers best practices for both lyophilized (pre-reconstitution) and reconstituted peptides.
Lyophilized Peptide Storage
Short-term (up to 6 months): Refrigerate at 2-8°C (36-46°F). Keep away from direct light.
Long-term (6+ months): Freeze at -20°C (-4°F). A standard household freezer is adequate.
Important: Lyophilized peptides are far more stable than reconstituted. Most vendors ship freeze-dried for this reason.
Desiccant: Keep the desiccant packet in the storage bag until use. It absorbs moisture that can degrade the powder.
Reconstituted Peptide Storage
Always refrigerate reconstituted peptides at 2-8°C. Never leave at room temperature for more than a few hours.
Shelf life: Approximately 4-6 weeks with bacteriostatic water (BAC water). The benzyl alcohol preservative in BAC water maintains sterility and slows degradation.
Do NOT freeze reconstituted peptide more than once. Each freeze-thaw cycle causes ice crystal formation that mechanically damages the peptide chain. If you plan to freeze, use smaller aliquots that can each be thawed once.
Protect from light: Aluminum foil wrapped around the vial helps — UV light degrades peptides over time.
BAC Water vs Sterile Water
Bacteriostatic water (BAC water): Contains 0.9% benzyl alcohol which inhibits bacterial growth. Extends reconstituted shelf life to 4-6 weeks. This is the standard choice for most peptides.
Sterile water: No preservative. Shelf life after reconstitution is only 24 hours. Use only if BAC water is not tolerated (rare sensitivity to benzyl alcohol).
Acetic acid (0.1%): Sometimes used for specific peptides like IGF-1 and some growth hormone variants. Check the specific reconstitution guidance for your peptide.
Signs of Degradation
Discard if you observe:
- Yellow or brown color change (clear/colorless is correct)
- Visible particles that do not dissolve
- Cloudiness that persists after mixing
- Gel-like consistency
- Unusual smell
Degraded peptides may still appear clear in early stages — if in doubt about storage history or age, err on the side of caution and replace.
Key Takeaways
The two most important rules: store lyophilized peptides in the freezer for long-term storage, and use bacteriostatic water (not sterile water) for reconstitution to get 4-6 weeks of refrigerated shelf life. Never leave reconstituted peptides at room temperature.