Peptide storage & stability.
Stability windows for lyophilised and reconstituted research peptides. Reconstitution-date calculator anchors the maths to real dates. Pick a compound for its specific window — GHK-Cu extends to 60 days, HGH conservatively to 14.
| Form | Room temp | Fridge (2–8°C) | Freezer (-20°C) |
|---|---|---|---|
Lyophilised (unopened) Avoid freeze-thaw cycles for long-term frozen storage — divide aliquots if planning multiple working solutions. | Several weeks | Several months | 12+ months |
Reconstituted in bacteriostatic water Bacteriostatic water (0.9% benzyl alcohol) inhibits microbial growth in solution. Sterile water alone does not — only use bac water for solutions you'll store more than a few hours. | Not recommended | ~28–30 days | Not recommended for most peptides |
Reconstituted in sterile water (no preservative) Sterile water has no antimicrobial action. Reconstituting with sterile water is only appropriate when the working solution is used immediately. | Not recommended | Use within 1–2 days | Not recommended |
Intranasal peptides (Semax, Selank) in nasal spray Nasal delivery introduces airborne contamination risk. Replace the working solution at the same 28–30 day window as injectable formats. | Not recommended | ~28–30 days | Not recommended once in nasal bottle |
Frequently asked.
How long do reconstituted peptides last in the fridge?+
Most reconstituted research peptides in bacteriostatic water retain integrity for ~28–30 days at 2–8°C. Compound-specific windows can vary — for example, GHK-Cu reconstituted with bac water is stable for up to 60 days under refrigeration, while some short-chain peptides degrade faster. Check the product page for compound-specific notes.
Can I freeze reconstituted peptides?+
Generally not recommended. Freeze-thaw cycles introduce ice-crystal damage to peptide structure and can cause irreversible aggregation. The exception is long-term aliquot storage (e.g. dividing a single reconstituted batch into small portions and freezing each for one-time use) — but for most research workflows, refrigeration at 2–8°C and using within 30 days is preferable.
What's the difference between bacteriostatic water and sterile water?+
Bacteriostatic water is sterile water with 0.9% benzyl alcohol added as a preservative — the benzyl alcohol inhibits microbial growth in the multi-dose solution. Sterile water has no preservative. Use bacteriostatic water whenever you'll store the solution for more than a few hours; use sterile water only when the working solution is consumed in a single research session.
Does refrigeration extend lyophilised vial shelf life?+
Yes, considerably. Sealed lyophilised vials are stable at room temperature for several weeks in most cases, but extend to several months at 2–8°C and 12+ months in a -20°C freezer. The pharmaceutical industry default for long-term storage of lyophilised peptides is frozen, sealed, away from light.
Should I avoid light exposure?+
Yes. Direct light — particularly UV — can degrade peptide structure. Store vials in their original packaging or an opaque container. The fridge interior typically provides sufficient light protection on its own, but extended counter-storage of reconstituted solutions in clear bottles is worth avoiding.
Stability windows above are general research references drawn from peptide literature. Compound-specific windows vary — always read the product page for the compound in question. All values apply to research-use storage; clinical or therapeutic storage standards may differ. Read the full disclaimer.