How to Reconstitute GLP-1 Peptides
For laboratory and research use only. Not for human or veterinary use. The following describes a laboratory sample-preparation procedure for in-vitro research and is provided for educational purposes only.
Research peptides ship as a lyophilized (freeze-dried) powder for stability in transit. Before they can be used in a study they must be reconstituted — dissolved back into solution with a sterile diluent. This guide explains the reconstitution procedure used in the laboratory and the concentration math behind it. It is part of our GLP-1 research peptides hub.
What you need
- The lyophilized peptide vial (e.g., semaglutide, tirzepatide, or retatrutide)
- Sterile bacteriostatic water as the diluent — included free with every order
- A sterile syringe for transferring the diluent, and alcohol swabs for sterile technique
Bacteriostatic water is preferred over plain sterile water for any vial that will be accessed more than once, because its 0.9% benzyl alcohol preservative protects the prepared solution between draws.
The procedure
- Use sterile technique. Swab the stopper of both the peptide vial and the diluent vial with alcohol before entering them.
- Draw the diluent. Draw your calculated volume of bacteriostatic water into the syringe.
- Add it slowly. Inject the diluent down the inside wall of the peptide vial rather than directly onto the powder, to avoid foaming or denaturing the peptide.
- Do not shake. Gently swirl the vial until the powder is fully dissolved. Shaking can damage the peptide.
- Store properly. Refrigerate the reconstituted solution and protect it from light, per your laboratory protocol.
The concentration math
The volume of diluent you add determines the concentration of the resulting solution. More water means a lower concentration; less water means a higher one. The relationship is simply:
Concentration (mg/mL) = peptide amount (mg) ÷ diluent volume (mL)
For example, adding 2 mL of bacteriostatic water to a 10 mg vial yields a 5 mg/mL solution. Rather than work this by hand, use our free reconstitution calculator — enter the vial’s milligram content, the volume of bacteriostatic water, and your target concentration, and it returns the exact figures for your research.
Handling and storage notes
Keep the lyophilized powder cool and dark until reconstitution. Once reconstituted, store under refrigeration and use within the period your protocol specifies. Always re-swab the stopper before each entry to maintain sterility. Certificates of Analysis for every compound are on the Lab Results page.
Frequently asked questions
Why bacteriostatic water instead of sterile water?
Sterile water has no preservative and is intended for single use. Bacteriostatic water contains 0.9% benzyl alcohol, which suppresses bacterial growth and makes it suitable for vials accessed more than once.
How much water should I add?
It depends on the vial’s milligram content and the concentration your protocol calls for. The free calculator computes the exact diluent volume.
Should the vial be shaken?
No. Swirl gently until dissolved; shaking can degrade the peptide.
How is the solution stored?
Refrigerated and protected from light, used within the window your laboratory protocol specifies.
Disclaimer: This procedure describes laboratory sample preparation for in-vitro research only. Products supplied by MyGLP1Store are not approved drugs, not supplements, and not for human or veterinary use.