A high-purity peptide is only as good as the way it is kept. Temperature, light and moisture degrade material over time, usually invisibly. This is the general reference for handling lyophilized and reconstituted research peptides.
Which rule applies depends entirely on whether the material is still a dry cake, in solution, or being held long-term in solution.
Freeze-dried powder is the most stable form. Kept frozen, dark and dry, sealed vials remain viable for extended periods. Cool room temperature is fine for short transit windows.
Once dissolved, store refrigerated and use within a few weeks. Bacteriostatic water extends the usable window against sterile or plain water, because it inhibits microbial growth.
To hold a solution longer, split it into single-use aliquots and freeze. This avoids repeated freeze-thaw cycles across the whole batch, which are what actually damage the peptide.
These are general reference ranges, not a specification for a specific compound. Stability varies by peptide, and some are notably more fragile than others. Where a product page or its Certificate of Analysis states a compound-specific condition, that always takes precedence over this guide.
| State | Temperature | Protect from | Typical window |
|---|---|---|---|
| Lyophilized, sealed | -20 °C | Light, moisture | 18-36 months |
| Lyophilized, sealed | 2-8 °C | Light, moisture | Several months |
| Lyophilized, in transit | ≤ 25 °C | Prolonged heat | Days (shipping) |
| Reconstituted (bacteriostatic) | 2-8 °C | Light, agitation | 2-6 weeks |
| Reconstituted (sterile / plain) | 2-8 °C | Light, microbes | Use promptly |
| Reconstituted, aliquoted | -20 °C | Freeze-thaw cycles | Extended |
General reference figures for laboratory handling. Not compound-specific guidance, and not a claim about any particular lot.
Four steps, in order. The reconstitution calculator works out the volume before you start.
Let the peptide vial and the diluent, typically bacteriostatic water, equilibrate. Adding cold solvent to cold powder slows dissolution and encourages condensation inside the vial.
Introduce the measured diluent slowly, letting it run against the inside glass rather than jetting directly onto the powder. This protects the lyophilized cake.
Gently rotate the vial until fully dissolved. Vigorous shaking introduces shear and foaming that can denature peptides. Give it time; most go into solution within minutes.
Mark the reconstitution date on the vial and store it at 2-8 °C away from light. Track the dates so each solution is used well inside its stability window.
The calculator converts vial mass and diluent volume into a concentration, and tells you what a given draw contains.
Reconstitution calculator