Beginner's Guide to Peptide Reconstitution
January 14, 2025 · 6 min read · Editorial Team
Reconstitution is the process of dissolving a lyophilized (freeze-dried) peptide powder in a sterile diluent so it can be injected. Done correctly, it preserves peptide integrity and dosing accuracy. This guide covers the essentials.
What you need
- A sealed vial of lyophilized peptide
- Bacteriostatic water (0.9% benzyl alcohol) as the diluent
- Sterile syringes (commonly insulin syringes, U-100)
- Alcohol swabs
The math
Concentration is simply the vial mass divided by the volume of diluent added. For example, a 5 mg vial reconstituted with 2 mL of bacteriostatic water yields a concentration of 2.5 mg/mL.
To draw a 250 mcg (0.25 mg) dose from that concentration:
Step by step
- Swab the rubber stopper of both vials.
- Draw air into the syringe equal to the diluent volume.
- Inject air into the bacteriostatic water vial, then withdraw the desired volume.
- Slowly inject the water down the side of the peptide vial — never blast the powder directly.
- Gently swirl (do not shake) until dissolved.