How to Reconstitute Peptides | Paragon Peptides

Reconstitution is the process of adding a solvent (usually bacteriostatic water) to a lyophilized (freeze-dried) peptide powder so it becomes a clear, ready-to-use solution for laboratory research. Proper reconstitution ensures maximum stability, accurate dosing, and reliable research results.

Why Peptides Come Lyophilized

Freeze-drying removes almost all water, making the peptide extremely stable at room temperature for months or even years. Once reconstituted, the peptide becomes far more sensitive to temperature, light, and bacterial contamination — which is why correct technique matters.

What You Will Need

Lyophilized peptide vial (from Paragon Peptides)
Bacteriostatic Water (BAC water) – preferred for most research peptides
Sterile 1 mL or 3 mL syringe with 27–30 gauge needle (insulin syringe works well)
Alcohol swabs
Optional: Sterile vial for storage if you want to split doses

Step-by-Step Reconstitution Guide

Prepare your workspace
Work in a clean, well-lit area. Wipe the tops of both the peptide vial and the BAC water vial with an alcohol swab and let them dry.
Draw the solvent
Using your sterile syringe, draw the desired amount of bacteriostatic water. Common volumes are 1 mL or 2 mL per vial.
Inject slowly along the side of the vial
Tilt the peptide vial at a 45° angle. Slowly inject the water so it runs down the inner wall of the vial. Do NOT shoot the water directly onto the powder — this can damage the peptide.
Gently swirl (never shake)
Once all water is added, gently swirl the vial in small circles until the powder is fully dissolved. The solution should be clear. If it is cloudy or has particles, do not use it.
Label and store
Immediately label the vial with the peptide name, concentration, and date reconstituted. Store in the refrigerator (2–8°C). Do not freeze.

How Much Water Should I Use?

Most researchers aim for 1–2 mL of BAC water per vial. Example:
• 5 mg peptide + 1 mL water = 5 mg/mL (very concentrated)
• 5 mg peptide + 2 mL water = 2.5 mg/mL (easier to measure small doses)

Use the formula: Concentration (mg/mL) = Peptide amount (mg) ÷ Water volume (mL)

Bacteriostatic Water vs Sterile Water

Bacteriostatic water contains 0.9% benzyl alcohol and can be used for up to 28 days after opening. It is the standard choice for most peptide research. Sterile (sterilized) water has no preservative — use it only if you plan to finish the entire vial within 24–48 hours.

Storage After Reconstitution

Refrigerate immediately at 2–8°C (do not freeze)
Keep away from direct light
Most reconstituted peptides remain stable for 14–28 days when stored properly
Always check for cloudiness or particles before each use

Common Mistakes to Avoid

Shaking the vial instead of gently swirling
Injecting water directly onto the powder
Using tap water or non-sterile water
Leaving reconstituted peptides at room temperature for long periods
Using the same syringe/needle for multiple vials without proper sterilization

Ready for Your Research?

All peptides sold by Paragon Peptides arrive lyophilized in sterile vials and are HPLC-verified at ≥99% purity. Follow the steps above and you will have a stable, accurately dosed research solution every time.