How to Store Peptides: Lyophilized and Reconstituted
Complete guide to peptide storage. Lyophilized vs reconstituted, temperature, light, freeze-thaw cycles, and shelf life. Keep your peptides potent.
Overview
Proper storage is critical for maintaining peptide potency. Lyophilized (freeze-dried) peptides are stable for months to years when stored correctly. Reconstituted peptides require refrigeration and have a shorter shelf life.
What You Need
- Freezer (for long-term lyophilized storage)
- Refrigerator (for reconstituted peptides)
- Amber or opaque vials (if repackaging)
- Desiccant packets (optional, for lyophilized storage)
Step-by-Step Instructions
Understand the two storage states
Lyophilized (freeze-dried) peptides are the powder form in sealed vials. They are highly stable. Reconstituted peptides (dissolved in BW) are less stable and require refrigeration.
Store lyophilized peptides in the freezer
Sealed lyophilized vials should be stored in the freezer (-20°C / -4°F) for long-term storage (months to years). For short-term use (within 1-3 months), refrigeration is acceptable.
Protect from light
Peptides are sensitive to UV light. Store in a dark location or in amber/opaque vials. Avoid leaving vials on a countertop in sunlight.
Refrigerate reconstituted peptides
Once reconstituted with bacteriostatic water, store peptides in the refrigerator (2-8°C / 35-46°F). Most reconstituted peptides remain stable for 4-6 weeks.
Minimize freeze-thaw cycles for lyophilized peptides
Each freeze-thaw cycle slightly degrades lyophilized peptides. If you have a large vial you will use over many months, consider dividing it into smaller aliquots before reconstituting.
Check for signs of degradation
Discard peptides if: the solution becomes cloudy or develops particles, the color changes significantly, or the vial has been stored improperly. When in doubt, discard.
Common Mistakes to Avoid
Freezing reconstituted peptides
Fix: Freeze-thaw cycles damage reconstituted peptides. Only freeze lyophilized (powder) peptides. Refrigerate reconstituted peptides and use within 4-6 weeks.
Leaving lyophilized peptides at room temperature for extended periods
Fix: Room temperature storage accelerates degradation. Refrigerate for short-term use; freeze for long-term storage.
Exposing peptides to light
Fix: Store in a dark location or amber vials. UV light degrades many peptides.
Using peptides past their stability window
Fix: Reconstituted peptides are stable for 4-6 weeks refrigerated. Discard after this period even if the solution looks clear.
Frequently Asked Questions
How long do lyophilized peptides last?
When stored frozen (-20°C), lyophilized peptides can remain stable for 1-2 years or longer. Refrigerated, they are stable for 3-6 months. Room temperature storage significantly reduces shelf life.
Can I freeze reconstituted peptides?
No. Freeze-thaw cycles damage reconstituted peptides. Only freeze lyophilized (powder) peptides. Once reconstituted, refrigerate and use within 4-6 weeks.
What does a degraded peptide look like?
Cloudy solution, visible particles, or significant color change can indicate degradation. However, degraded peptides can also look normal. When in doubt, discard.
Do I need to keep peptides cold during shipping?
Lyophilized peptides tolerate short periods at room temperature (days to weeks) without significant degradation. For reconstituted peptides or extended transit, cold packs are recommended.
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