Peptide stability depends on several factors: whether the peptide has been reconstituted, how it is stored, and the specific compound in question. As a general rule, lyophilized peptides stored correctly are highly stable, while reconstituted peptides have a much shorter usable window.
Lyophilized (Freeze-Dried) Peptides:
When stored in the freezer at -20°C and kept away from moisture and light, most lyophilized peptides remain stable for 24 months or longer. Refrigerated storage at 2–8°C is suitable for shorter-term use, typically within 3–6 months. The lyophilization process is specifically designed to extend shelf life by removing water — the primary driver of peptide degradation — which is why all Peptide Club compounds are shipped in this form.
Reconstituted Peptides:
Once mixed with bacteriostatic water, the stability window shortens considerably. Reconstituted peptides stored in the refrigerator at 2–8°C should be used within 180 days. After this window, potency and integrity cannot be guaranteed. Freezing a reconstituted peptide is not recommended, as the freeze-thaw process disrupts the peptide structure and accelerates degradation.
Factors That Shorten Stability:
Heat — Elevated temperatures accelerate the breakdown of peptide bonds. Keep peptides away from warm environments and never leave vials at room temperature for extended periods.
Light — UV exposure degrades peptides over time. Store vials in dark conditions or in opaque containers. Moisture — Even small amounts of humidity can compromise a lyophilized peptide. Keep vials sealed until ready to use.
Repeated freeze-thaw cycles — Each cycle stresses the compound. If long-term storage is needed, consider dividing a batch into smaller aliquots so only what is needed is thawed at a time.
A Note on Peptide-Specific Variation:
Some peptides are inherently more stable than others due to differences in their amino acid sequences and structural properties. If you have questions about the expected stability of a specific compound in your order, our team at [email protected] can provide guidance based on the individual peptide.