How to Reconstitute Research Peptides: Step-by-Step Guide

Lyophilisation (freeze-drying) removes water from peptide solutions under vacuum, leaving behind a stable powder. This dramatically extends shelf life, lyophilised peptides can remain stable for 24+ months at −20°C, whereas a pre-mixed peptide solution typically degrades within weeks even under refrigeration.

All research peptides from OzPeps are supplied in lyophilised form and must be reconstituted with bacteriostatic water before use in research applications.

Bacteriostatic water, essentialEvery lyophilised peptide requires bacteriostatic water (BAC water) for reconstitution. OzPeps stocks pharmaceutical-grade bacteriostatic water 10mL →, available individually or bundled with peptide orders.

• Lyophilised peptide vial (e.g. BPC-157 10mg, Retatrutide 10mg)
• Bacteriostatic water 10mL (or the smaller 3mL for single-vial reconstitution), contains 0.9% benzyl alcohol to inhibit microbial growth
• Insulin syringe or 1mL luer-lock syringe
• Alcohol swabs
• Optional: vial label with reconstitution date and concentration

Do not use plain sterile water, bacteriostatic water's benzyl alcohol preservative extends the useable life of the reconstituted solution to 28–42 days. Plain sterile water has no preservative and degrades within 24 hours once opened.

1. Allow to warm, remove the peptide vial from the freezer and allow it to reach room temperature (5–10 minutes). Cold glass can crack if liquid is injected rapidly.
2. Wipe the stopper, clean the rubber stopper of both the peptide vial and the BAC water vial with an alcohol swab. Allow to air dry.
3. Draw BAC water, using a syringe, draw the required volume of bacteriostatic water (see concentration table below).
4. Inject slowly, insert the needle through the rubber stopper of the peptide vial and inject the BAC water slowly down the inside wall of the glass. Do not inject directly onto the powder as this can damage peptide structure.
5. Gently swirl, do not shake. Swirl the vial gently until the powder is fully dissolved. Most peptides dissolve within 30–60 seconds. If the solution appears cloudy, allow it to rest for a few minutes and swirl again.
6. Inspect, the reconstituted solution should be clear and colourless. Discard if particulate matter is visible.
7. Store correctly, refrigerate at 2–8°C. Label with reconstitution date. Use within 28–42 days.

Common reconstitution volumes and resulting concentrations for a 10mg peptide vial:

Use OzPeps' free reconstitution calculator for any vial size or target concentration.

• Refrigerate at 2–8°C (standard household fridge is fine)
• Keep away from light, store in the vial box or wrapped in foil
• Avoid repeated temperature cycling
• Use within 28–42 days of reconstitution
• Do not freeze a reconstituted peptide solution, this damages peptide structure

Lyophilised (dry powder) and reconstituted (solution) peptides have very different storage requirements and shelf lives:

• Light: keep vials away from light, UV exposure can cause photodegradation of aromatic residues (phenylalanine, tyrosine, tryptophan)
• Freeze-thaw: if freezing a reconstituted solution, aliquot into single-use volumes first, repeated freeze-thaw cycles degrade peptide structure
• Condensation: allow a lyophilised vial to reach room temperature before opening to prevent moisture forming on the powder

Why bacteriostatic water and not sterile water? Bacteriostatic water contains 0.9% benzyl alcohol, a preservative that inhibits microbial growth after the vial is punctured, extending a reconstituted solution's usable life to roughly 28–42 days refrigerated. Plain sterile water has no preservative and should be used within 24 hours once opened.

What does the benzyl alcohol do? At 0.9% it inhibits gram-positive and gram-negative bacteria, yeasts, and moulds without meaningfully affecting peptide solubility or activity at standard reconstitution concentrations, which is why it is the standard diluent for multi-draw research vials.

OzPeps supplies pharmaceutical-grade bacteriostatic water 10mL → alongside peptide orders.

• BPC-157, dissolves easily; stable in acidic conditions; one of the more forgiving peptides to work with
• Retatrutide, 39-amino-acid sequence; allow slightly longer to dissolve; store reconstituted solution at 2–8°C for no more than 28 days
• TB-500, may require gentle warming of BAC water (not hot) to aid dissolution of longer peptide chains
• NAD+, highly water soluble; dissolves quickly; once reconstituted is less stable than lyophilised peptides, use within 7–14 days
• GHK-Cu, copper peptide; solution may have a faint blue-green tint, this is normal

Browse the full OzPeps catalogue including bacteriostatic water and research supplies: View all products →

This guide is provided for educational and laboratory research purposes only. All peptides from OzPeps are for in-vitro research use only, not for human or animal consumption, and are not TGA-approved therapeutic goods.