LAB TECHNIQUE

Peptide Reconstitution: A Technical Reference

Velox Peptides Research Team·Published May 2026·7 min read
For in vitro research use only. This is a technical reference for handling research reagents in vitro. It is not guidance for human use; all Velox Peptides compounds are for in vitro research use only and not for human or veterinary consumption.

What reconstitution means

Research peptides are supplied as a lyophilised (freeze-dried) powder for stability. Reconstitution is the process of dissolving that powder in a suitable solvent to produce a solution of known concentration for laboratory work. Doing it correctly — with the right solvent, volume and handling — is essential both for accurate concentrations and for preserving the peptide.

Use the reconstitution calculator to work out exact volumes for your target concentration.

Choosing a solvent: bacteriostatic water

The most common reconstitution solvent for research peptides is bacteriostatic water — sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth and allows a reconstituted vial to be stored for longer than plain sterile water permits. Some peptides with poor aqueous solubility may require a small amount of a co-solvent before dilution, which should be determined per compound.

Always add the solvent slowly, directing it against the side of the vial rather than firing it directly onto the powder, and allow the peptide to dissolve gently without vigorous shaking.

Concentration calculations

Concentration is simply the mass of peptide divided by the volume of solvent. For example, reconstituting a 10 mg vial with 2 mL of bacteriostatic water gives a concentration of 5 mg/mL. Choosing the reconstitution volume therefore sets your working concentration — a smaller volume gives a more concentrated solution.

The reconstitution calculator handles this both ways: enter your vial size and target concentration to get the volume, or enter the volume to get the resulting concentration.

Sterile handling and storage

Handle reconstitution under clean conditions: wipe vial stoppers with an alcohol swab before piercing, use a fresh sterile syringe, and avoid touching the needle or stopper surface. Once reconstituted, peptides are generally stored refrigerated at 2–8°C and protected from light; lyophilised (un-reconstituted) vials are more stable and are typically stored cold and desiccated for long-term keeping.

Reconstituted shelf life varies by compound; bacteriostatic water extends it relative to plain water, but reconstituted solutions should still be used within the window appropriate to the peptide. Avoid repeated freeze-thaw cycles.

Frequently asked questions

What is bacteriostatic water?
Sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth and allows a reconstituted vial to be stored longer than plain sterile water permits.
How do I calculate peptide concentration?
Concentration = mass of peptide ÷ volume of solvent. A 10 mg vial in 2 mL gives 5 mg/mL. The reconstitution calculator does this automatically.
How should reconstituted peptides be stored?
Generally refrigerated at 2–8°C, protected from light, and used within the window appropriate to the compound. Avoid repeated freeze-thaw cycles.
Where is the reconstitution calculator?
On the tools page — it converts between vial size, target concentration and solvent volume.
Compliance statement. Velox Peptides supplies research reagents for in vitro use by qualified researchers. Every compound is sold strictly as a research reagent. No product is a medicinal product within the meaning of the Human Medicines Regulations 2012. No product has been evaluated by the MHRA or FDA. No product is intended for human or veterinary consumption, diagnosis, treatment, cure, or prevention of any condition. Any use outside lawful scientific research is outside the scope of sale. See our Research Use Policy and MHRA Statement.

All research summaries on this page are derived from publicly available peer-reviewed literature. Velox Peptides makes no therapeutic claims. For research use only.