Lyophilised (freeze-dried) peptides arrive as a solid powder in a sealed vial. Before they can be used in laboratory research, they must be reconstituted — dissolved back into a liquid. Done correctly, reconstitution is simple. Done carelessly, it can degrade the peptide or introduce error into your measurements. This guide walks through the process step by step.
*This is a laboratory research guide. All Peptide Pal compounds are for in-vitro research only and are not for human consumption or administration.*
## What you will need
- Your lyophilised peptide vial
- Bacteriostatic water (the standard reconstitution solvent for research peptides — sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth and allows the solution to be stored)
- A sterile syringe
- An alcohol wipe
- Your reconstitution calculation (see below)
## Step 1: Calculate your volume
Before mixing anything, decide how much bacteriostatic water to add. This determines the concentration of your final solution, which is what lets you measure accurate amounts later.
The relationship is simple: more water = a more dilute solution = a larger, easier-to-measure volume per unit of peptide. Less water = more concentrated.
Rather than doing the maths by hand, use our free [Peptide Reconstitution Calculator](/pages/peptide-calculator). Enter the amount of peptide in the vial and your target concentration, and it tells you exactly how much bacteriostatic water to add and the resulting draw volume. This removes the most common source of reconstitution error.
## Step 2: Prepare the vials
Let both the peptide vial and the bacteriostatic water reach room temperature. Wipe the rubber stopper of each vial with an alcohol wipe and let it dry. This keeps the process clean and the solution stable.
## Step 3: Draw the bacteriostatic water
Using your sterile syringe, draw up the exact volume of bacteriostatic water your calculation specified. Keep everything sterile — do not touch the needle or let it contact any non-sterile surface.
## Step 4: Add the water slowly — this is the important part
Insert the needle into the peptide vial at an angle so the water runs down the **inside wall of the glass**, not directly onto the powder. Release it slowly.
Peptides are delicate molecules. Blasting a fast stream of water straight onto the lyophilised powder can shear and damage the peptide chains. A slow trickle down the side preserves them.
## Step 5: Mix gently — do not shake
Once the water is in, gently swirl or roll the vial between your fingers until the powder fully dissolves. It usually clears within a minute or two.
**Never shake the vial.** Shaking creates foam and mechanical stress that can denature the peptide. Patience here protects the compound you paid for.
The solution should end up clear and colourless. If it stays cloudy, contains visible particles, or changes colour, do not use it — something is wrong, either with the handling or the compound.
## Step 6: Store it correctly
Once reconstituted, the solution must be kept refrigerated at 2–8°C. Because bacteriostatic water contains a preservative, a properly stored reconstituted peptide typically remains stable for several weeks — but always follow the specific guidance in your product documentation, as this varies by compound.
Keep the vial away from light and never freeze a reconstituted solution unless the documentation specifically allows it, as freeze-thaw cycles can damage peptides.
## Common mistakes to avoid
- **Adding water too fast** — damages the peptide (see Step 4)
- **Shaking instead of swirling** — denatures the compound
- **Using ordinary tap or distilled water** — no preservative, so the solution cannot be stored and risks contamination
- **Guessing the volume** — use the [calculator](/pages/peptide-calculator) instead
- **Storing at room temperature** — reconstituted peptides need refrigeration
## Summary
Reconstitution comes down to three principles: calculate your volume precisely, add the water gently down the side of the glass, and swirl rather than shake. Get those right and store the result cold, and your research compound stays intact and accurately measurable.
Explore our full range of [research-grade peptides](/pages/buy-peptides), each supplied with a Certificate of Analysis, or read the [peer-reviewed studies](/pages/studies) behind them. Questions about a specific compound? [Contact our team](/pages/support) — we reply within one business day.
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*All compounds supplied by Peptide Pal are strictly for in-vitro laboratory research and are not for human consumption, self-administration, or medical use.*