Most research peptides — including BPC-157, TB-500 and the GLP-1 family — are shipped lyophilised, meaning freeze-dried into a stable powder. Before they can be used in a research setting they need to be returned to liquid form. That process is called reconstitution, and doing it correctly is the difference between repeatable data and wasted material.
What reconstitution means
Reconstitution simply means adding a sterile liquid to the dry peptide so it dissolves into a solution of known concentration. The standard diluent is bacteriostatic water — sterile water containing a small amount of benzyl alcohol that inhibits bacterial growth, allowing the solution to be stored for longer than plain sterile water would permit.
What you need
- The lyophilised peptide vial
- Bacteriostatic water (the diluent)
- A sterile syringe for drawing and adding the water
- Alcohol wipes for the vial stoppers
- A calculator — or our peptide reconstitution calculator
The concentration maths
The key relationship is straightforward: concentration = peptide amount ÷ water volume. The more bacteriostatic water you add, the more dilute the solution and the larger the draw volume for a given amount of peptide.
For example, reconstituting a 5 mg vial with 2 mL of bacteriostatic water gives a concentration of 2.5 mg/mL. To work out the volume that corresponds to a target amount, divide the target by the concentration. Rather than do this by hand, our calculator converts vial size and water volume into concentration and per-unit draw automatically.
Step-by-step procedure
- Calculate first. Decide the target concentration and use the calculator to determine how much bacteriostatic water to add.
- Bring vials to room temperature. Let both the peptide and the water equilibrate, then wipe each stopper with an alcohol wipe.
- Draw the water. Pull the calculated volume of bacteriostatic water into the syringe.
- Add it slowly. Insert the needle and let the water run gently down the inside wall of the vial — never blast it directly onto the powder.
- Swirl, don't shake. Rotate the vial gently until the powder fully dissolves. Shaking introduces foaming and shear stress that can degrade the peptide.
- Inspect. The solution should be clear. Discard if it remains cloudy or shows particulates after dissolving.
Storage & stability
Once reconstituted, peptides are far less stable than in their dry form. As a general rule:
- Lyophilised (unopened): store in the freezer; stable for extended periods.
- Reconstituted: refrigerate and use within a few weeks, depending on the specific peptide.
- Always: keep vials out of direct light and avoid repeated temperature swings.
HealthHub Research pens are buffer-stabilised and supplied pre-filled, which removes much of the handling variability — but understanding the underlying process is still essential for any researcher working from raw vials.
Common mistakes to avoid
- Shaking the vial — agitation damages the peptide; always swirl.
- Spraying water onto the powder — aim for the glass wall instead.
- Skipping the maths — guessing the concentration makes every later measurement unreliable.
- Using the wrong diluent — bacteriostatic water is standard; plain sterile water shortens shelf life.
- Leaving solutions at room temperature — refrigerate promptly after reconstitution.
Skip the guesswork with the calculator
Enter your vial size and water volume to get concentration and draw volume instantly — no manual maths required.
Open the calculatorFrequently asked questions
What water do you use to reconstitute peptides?
Bacteriostatic water is the standard diluent for research peptides because the small amount of benzyl alcohol it contains inhibits bacterial growth and extends storage life compared with plain sterile water.
Should you shake the vial to dissolve the powder?
No. Swirl the vial gently instead. Shaking creates foam and shear stress that can degrade the peptide and reduce its integrity.
How long does a reconstituted peptide last?
Once reconstituted, peptides are generally refrigerated and used within a few weeks, though exact stability varies by compound. Unopened lyophilised vials keep much longer when frozen.
This article is provided for educational and scientific reference only and does not constitute medical advice. All products referenced are sold strictly for laboratory research use, are not for human or animal consumption, and are not intended to diagnose, treat, cure or prevent any disease.