What Is Reconstitution? How to Mix Peptides Safely

Reconstitution is the process of dissolving a freeze-dried (lyophilised) peptide powder into a liquid solution so it can be accurately measured and used. Nearly all research peptides are supplied as a lyophilised powder — a white or off-white cake or powder in a small glass vial.

The freeze-drying process removes all moisture, which dramatically extends the peptide's shelf life. A lyophilised peptide stored properly can remain stable for months or even years. However, once reconstituted (mixed with water), the peptide becomes much less stable and must be refrigerated and used within a specific timeframe.

Reconstitution is a straightforward process, but it requires attention to sterility, gentle handling, and accurate measurement to ensure the peptide remains intact and doses are correct.

The two most common solvents for peptide reconstitution are:

Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol as a preservative. This is the preferred choice for most research peptides because: - The preservative inhibits bacterial growth, allowing the solution to be used over multiple days - It's safe for injection when used as directed - Reconstituted peptides typically remain stable for 3-4 weeks when refrigerated

Sterile water (water for injection) contains no preservative. It's used when: - The peptide is sensitive to benzyl alcohol - The entire vial will be used in a single session - Reconstituted solution should be used within 24 hours due to the lack of preservative

Sodium chloride (0.9% saline) is occasionally used for specific peptides, particularly when isotonicity is important.

For most research peptides, bacteriostatic water is the standard and recommended choice.

Follow these steps carefully to reconstitute a peptide vial:

Step 1: Gather supplies - Peptide vial (lyophilised powder) - Bacteriostatic water - Insulin syringe (1ml/100 units) or appropriate syringe — see our syringe types for peptides guide for size and needle gauge options - Alcohol swabs

Step 2: Clean the vial tops Wipe the rubber stoppers of both the peptide vial and the BAC water vial with alcohol swabs. Allow to air dry for 10-15 seconds.

Step 3: Draw up the water Using a clean syringe, draw up the desired amount of bacteriostatic water. Common amounts are 1ml or 2ml, depending on the peptide dose and vial size.

Step 4: Add water to the peptide vial Insert the needle into the peptide vial through the rubber stopper. Critically important: aim the stream of water down the inside wall of the vial, not directly onto the powder. Release the water slowly and gently.

Step 5: Allow to dissolve Do NOT shake the vial. Gently swirl or roll it between your palms if needed. Most peptides will dissolve within 1-5 minutes. Some may take slightly longer. The solution should become clear — if it remains cloudy, the peptide may be degraded.

Step 6: Store properly Place the reconstituted vial in the refrigerator (2-8°C). Label it with the date and the concentration.

Once reconstituted, you need to know how much liquid to draw up for a specific dose. The calculation depends on how much water you added.

The formula: Dose volume (ml) = Desired dose (mcg) ÷ Concentration (mcg/ml)

Example: - Vial contains 5mg (5,000mcg) of BPC-157 - You add 2ml of BAC water - Concentration = 5,000mcg ÷ 2ml = 2,500mcg per ml - If your desired dose is 250mcg: 250 ÷ 2,500 = 0.1ml (or 10 units on an insulin syringe)

Using insulin syringes: Standard insulin syringes are marked in "units" where 100 units = 1ml. So: - 0.1ml = 10 units - 0.25ml = 25 units - 0.5ml = 50 units

Pro tip: Our Dosage Calculator tool can do this maths for you — simply enter the vial size, the amount of water added, and your desired dose.

Adding more water makes doses easier to measure (more volume per dose) but means the vial is used up faster. Adding less water makes the solution more concentrated but doses become tiny volumes that are harder to measure accurately.

Avoid these frequent errors that can degrade your peptide or lead to inaccurate dosing:

Shaking the vial: Peptides are fragile molecules. Vigorous shaking creates foam and can break peptide bonds through mechanical stress. Always swirl gently or let the peptide dissolve naturally.

Spraying water directly onto the powder: High-pressure water hitting the lyophilised cake can damage the peptide. Always aim down the side of the vial and release slowly.

Using non-sterile water: Tap water, distilled water, or non-sterile purified water can introduce bacteria. Only use bacteriostatic water or sterile water for injection.

Incorrect temperature: Store reconstituted peptides in the fridge, not the freezer. Freezing a reconstituted peptide can cause it to denature. The lyophilised powder (before reconstitution) can be frozen for long-term storage.

Reusing needles: Always use a fresh, sterile needle each time you draw from the vial. Reusing needles introduces bacteria and dulls the needle.

Not labelling vials: If you have multiple peptides, it's easy to mix them up. Always label each vial with the peptide name, concentration, and reconstitution date.

Proper storage is critical for maintaining peptide potency:

Refrigeration (2-8°C): Store all reconstituted peptides in the refrigerator. Most peptides remain stable for 3-4 weeks when reconstituted with bacteriostatic water and stored cold.

Avoid light: Some peptides are light-sensitive. Store vials in a dark area of the fridge or wrap them in aluminium foil.

Avoid contamination: Always clean the vial stopper with an alcohol swab before each use. Use a fresh needle each time.

Shelf life guidelines (reconstituted with BAC water, refrigerated): - Most peptides: 21-30 days - Some sensitive peptides (e.g., certain growth hormone secretagogues): 14-21 days - Reconstituted with sterile water (no preservative): use within 24 hours

Lyophilised (unreconstituted) storage: - Refrigerator: stable for 12+ months - Freezer (-20°C): stable for 2+ years - Room temperature: stable for several weeks, but refrigeration is always preferred

If a reconstituted solution becomes cloudy, discoloured, or develops particles, discard it — the peptide has likely degraded.