Lyophilized (freeze-dried) peptides are most stable sealed, dry, cold and dark. For long-term storage, keep unopened vials at −20 °C. For short-term storage, 2–8 °C is fine. Once a peptide is reconstituted in the lab, keep it at 2–8 °C, protect it from light, and avoid repeated freeze-thaw cycles. This guide covers each step, with a quick reference table at the end.
Why lyophilized peptides are stable
Lyophilization removes water from a peptide by freezing it and then drawing the ice off under vacuum. Most peptide degradation pathways, such as hydrolysis, deamidation and oxidation, need water or oxygen. Removing water slows them sharply. That is why a sealed lyophilized vial can stay stable far longer than the same peptide in solution.
Temperature
- Long-term (months or more): −20 °C in a standard laboratory freezer. A manual-defrost freezer is better than a frost-free one, because frost-free models cycle temperature.
- Short-term (weeks): 2–8 °C refrigeration.
- In transit: sealed lyophilized peptides tolerate room temperature for the few days of shipping. Move them to cold storage when they arrive.
Moisture and light
Let a cold vial reach room temperature before opening it. Opening a cold vial pulls condensation onto the powder. Keep vials capped, and store them in their box or an opaque container away from direct light. Peptides that contain tryptophan, tyrosine, cysteine or methionine are especially prone to light- and oxygen-driven degradation.
After reconstitution
A peptide in solution is far less stable than a dry powder. In laboratory practice:
- Reconstitute with a sterile solvent suited to the peptide. Bacteriostatic water and sterile water are the most common for water-soluble peptides. See our 10 mL and 30 mL reconstitution solutions.
- Add solvent gently down the side of the vial and swirl. Don’t shake, because agitation can cause aggregation.
- Store the solution at 2–8 °C and protect it from light.
- If the solution needs to be kept longer, split it into single-use aliquots and freeze them. That way each aliquot is thawed only once.
- Label every vial with the compound, concentration, solvent, lot number and reconstitution date.
Capsule products
Capsule-form research compounds, such as our Dihexa, SLU-PP-332 and BPC-157 / KPV / Larazotide, should stay in the sealed bottle with the desiccant, in a cool, dry place away from light. Refrigeration at 2–8 °C extends stability.
Signs a peptide may have degraded
- The powder has collapsed, turned sticky or changed color
- The solution is cloudy or has visible particles after it should have dissolved
- The vial seal is broken, or the vial was left warm and exposed to moisture
When in doubt, compare against the lot’s Certificate of Analysis, or contact support@nextlevelcompounds.com.
Quick reference
| Form | Where | Notes |
|---|---|---|
| Lyophilized, sealed (long-term) | −20 °C | Dark, dry, manual-defrost freezer preferred |
| Lyophilized, sealed (short-term) | 2–8 °C | Keep in box, away from light |
| Lyophilized, in transit | Room temperature | Move to cold storage on arrival |
| Reconstituted solution | 2–8 °C | Protect from light, don’t shake, label it |
| Reconstituted, longer hold | −20 °C aliquots | Thaw each aliquot only once |
| Capsules | Cool, dry; 2–8 °C optional | Keep sealed with desiccant |
All Next Level Compounds products are for laboratory research use only. Not for human consumption. This guide covers storage and handling in a laboratory setting only and is not use or dosing guidance.