Back to Research

How to Reconstitute a Peptide Vial

Updated April 3, 2026

Written by NorthPeptide Research Team | Reviewed March 16, 2026

To reconstitute a peptide vial, draw the appropriate volume of bacteriostatic water into a sterile syringe, inject it slowly along the inside wall of the vial, and gently swirl until the lyophilized powder dissolves completely. Never shake the vial — this can denature the peptide and destroy its structure.

Step-by-Step Process

1. Gather supplies: Bacteriostatic water (BAC water), alcohol swabs, a sterile syringe (typically 1mL insulin syringe), and your lyophilized peptide vial.

2. Clean: Swab the rubber stopper of both the peptide vial and the BAC water vial with alcohol. Allow to air dry for 10 seconds.

3. Draw water: Draw your desired volume of BAC water into the syringe. A common reconstitution volume is 1–2mL per vial, depending on desired concentration.

4. Inject slowly: Insert the needle through the peptide vial stopper and direct the stream of water against the glass wall — not directly onto the powder. Let the water run down the side gently.

5. Dissolve: Gently swirl or roll the vial between your palms. Most peptides dissolve within 30–60 seconds. If the powder doesn’t dissolve, refrigerate for 15 minutes and try again. Never shake vigorously.

Calculating Concentration

If your vial contains 5mg of peptide and you add 2mL of BAC water, the concentration is 2.5mg/mL (5mg ÷ 2mL). Each 0.1mL (10 units on an insulin syringe) would contain 250mcg. Choose your reconstitution volume based on the measurement precision you need.

Common Mistakes

Shaking the vial creates foam and denatures the peptide through mechanical stress. Using sterile water instead of BAC water eliminates the preservative (benzyl alcohol), reducing shelf life from ~28 days to 48–72 hours. Spraying water directly onto the powder cake can cause clumping.

Related Resources


Written by NorthPeptide Research Team · For laboratory and research use only. Not for human consumption.

Written by NorthPeptide Research Team

Ready to explore research-grade peptides?

Browse All Peptides →

Products mentioned in this article:

All NorthPeptide products include third-party analytical testing, batch-specific COAs, and free shipping on orders over $150. Browse all research peptides →

Research Disclaimer: All articles are intended for informational and educational purposes only. Products referenced are sold strictly for laboratory and in-vitro research use. Not for human consumption. By purchasing, you agree to our research policy and confirm you are a qualified researcher.