Lyophilization — freeze-drying — is the standard preservation method for research peptides. It removes water from the peptide solution, leaving a stable powder that can be stored at room temperature for months. Before use, the peptide must be reconstituted by adding a precise volume of sterile liquid. This guide covers the complete reconstitution process, from materials to storage.
What You Need
- Lyophilized peptide vial (your research compound)
- Bacteriostatic water (BW) — preferred for multi-dose vials due to benzyl alcohol preservative
- Sterile water for injection (SWFI) — acceptable for single-use reconstitution
- Insulin syringes (100-unit / 1mL) for accurate measurement
- Alcohol swabs (70% isopropyl)
- Clean, flat surface and good lighting
Step-by-Step Reconstitution Protocol
Begin by wiping both the peptide vial's rubber stopper and the bacteriostatic water vial's stopper with an alcohol swab. Allow them to air-dry for 30 seconds — do not blow on them or wipe them dry. Draw your target volume of bacteriostatic water into the insulin syringe. The most common starting volume for a 5mg vial is 2mL, yielding a 2,500 mcg/mL concentration.
Insert the needle into the peptide vial at a 45-degree angle and slowly inject the bacteriostatic water down the side of the vial — never directly onto the peptide powder. This prevents foaming and degradation from mechanical agitation. Once all the water is added, gently swirl the vial (do not shake) until the powder is fully dissolved. The solution should be clear and colorless. Any cloudiness, particulates, or color change indicates degradation.
Reconstitution Volume Reference
| Peptide Amount | BW Volume | Final Concentration | Per 10 units (0.1mL) |
|---|---|---|---|
| 2 mg | 1 mL | 2,000 mcg/mL | 200 mcg |
| 2 mg | 2 mL | 1,000 mcg/mL | 100 mcg |
| 5 mg | 1 mL | 5,000 mcg/mL | 500 mcg |
| 5 mg | 2 mL | 2,500 mcg/mL | 250 mcg |
| 10 mg | 2 mL | 5,000 mcg/mL | 500 mcg |
| 10 mg | 4 mL | 2,500 mcg/mL | 250 mcg |
Storage After Reconstitution
Once reconstituted, peptides must be refrigerated at 2–8°C (36–46°F). Bacteriostatic water extends the usable life of a reconstituted peptide to approximately 28–30 days when refrigerated. Keep vials away from light — a small piece of aluminum foil over the vial provides adequate protection. Do not freeze reconstituted peptides; the ice crystal formation damages the peptide structure.
| State | Storage Temperature | Shelf Life |
|---|---|---|
| Lyophilized (dry powder) | Room temp (15–25°C) | 12–24 months |
| Lyophilized (dry powder) | Refrigerated (2–8°C) | 24–36 months |
| Reconstituted with BW | Refrigerated (2–8°C) | 28–30 days |
| Reconstituted with SWFI | Refrigerated (2–8°C) | 24–48 hours |
Common Mistakes to Avoid
- Adding too much or too little bacteriostatic water (always calculate concentration first)
- Injecting water directly onto the peptide powder (causes foaming)
- Shaking the vial instead of swirling
- Using regular sterile water for multi-dose vials
- Storing reconstituted peptides at room temperature
- Freezing reconstituted peptides
- Failing to swab the vial stopper before each draw