How to Reconstitute Peptides: Step-by-Step Guide

What Is Reconstitution?

Reconstitution is the process of dissolving a lyophilised (freeze-dried) peptide powder into a liquid solution so it can be measured and administered accurately. Most research peptides arrive as a fine powder in a sealed vial and must be mixed with a sterile solvent before use.

What You Need

Before you begin, gather the following supplies:

• Lyophilised peptide vial — the sealed vial containing your peptide powder
• Bacteriostatic water (BAC water) — sterile water preserved with 0.9% benzyl alcohol. This is the standard solvent for most peptides
• Insulin syringes — U-100 insulin syringes (1mL with 100 unit markings) for accurate measurement
• Alcohol swabs — to sterilise vial stoppers before puncturing
• Clean workspace — a flat, clean surface away from direct sunlight

Step-by-Step Instructions

Step 1

Draw BAC water

Use a fresh insulin syringe. Calculate volume with the calculator.

Step 2

Drip down the wall

Insert at an angle, needle tip on glass. Avoid direct contact with the powder.

Step 3

Gently roll, never shake

Vigorous shaking can damage peptide bonds and reduce potency.

Properly reconstituted solution is clear and colourless. Cloudiness or floating particles signal a compromised product.

Step 1: Prepare Your Workspace

Clean your workspace with an alcohol wipe or disinfectant. Wash your hands thoroughly. Lay out all supplies.

Step 2: Determine Your Water Volume

The amount of bacteriostatic water you add determines the concentration of your solution. Common reconstitution volumes:

Peptide Amount	Water Added	Concentration
5 mg	1 mL	5,000 mcg/mL
5 mg	2 mL	2,500 mcg/mL
10 mg	2 mL	5,000 mcg/mL
10 mg	5 mL	2,000 mcg/mL

Use our Reconstitution Calculator to determine the exact volume for your specific peptide and desired dose.

Step 3: Sterilise the Vial Tops

Swab the rubber stopper of both the peptide vial and the bacteriostatic water vial with an alcohol swab. Allow to air dry for a few seconds.

Step 4: Draw Up the Bacteriostatic Water

Using a fresh insulin syringe, draw up the calculated amount of bacteriostatic water from the BAC water vial.

Step 5: Add Water to the Peptide Vial

Insert the syringe needle into the peptide vial at an angle, with the needle tip touching the inside glass wall. Do not inject the water directly onto the powder. Instead, let the water drip slowly down the side of the vial. This prevents damage to the peptide structure.

Step 6: Allow the Peptide to Dissolve

After adding the water, gently roll the vial between your palms for 30-60 seconds. Never shake the vial vigorously — this can damage peptide bonds and reduce potency. Most peptides will dissolve within 1-2 minutes. If small particles remain, place the vial in the refrigerator and check again after 30 minutes.

Step 7: Verify the Solution

A properly reconstituted peptide solution should be clear and colourless. If the solution is cloudy, contains visible particles that do not dissolve, or appears discoloured, the peptide may be compromised and should not be used.

Storage After Reconstitution

Refrigerate

2–8 °C

Reconstituted vials. Up to 28 days with BAC water.

Lyophilised

−20 °C

Long-term storage for unopened, freeze-dried powder.

Room temp

15–25 °C

Short trips only — return to fridge promptly.

Never freeze

—

Reconstituted solutions: freezing damages peptide structure.

• Refrigerate immediately at 2-8°C (36-46°F)
• Never freeze a reconstituted peptide solution
• Use within 28-30 days of reconstitution when stored with bacteriostatic water
• Protect from light — store in a dark area of the refrigerator
• Do not leave at room temperature for extended periods

Common Mistakes to Avoid

1. Spraying water directly onto the powder — this can denature the peptide
2. Shaking the vial — always roll gently
3. Using sterile water instead of BAC water — sterile water lacks preservative and shortens shelf life to 24-48 hours
4. Incorrect volume calculation — double-check your math or use our calculator
5. Contamination — always swab vial tops and use fresh syringes

Frequently Asked Questions

Can I use sterile water instead of bacteriostatic water?

Technically yes, but the reconstituted peptide must be used within 24-48 hours as sterile water contains no preservative. Bacteriostatic water extends usable life to approximately 28 days.

How do I know if my peptide has gone bad?

Signs of degradation include cloudiness, particles that do not dissolve, unusual colour, or unusual odour. When in doubt, discard the vial.

Does the amount of water I add matter?

Yes. The water volume determines the concentration, which affects how much liquid you need to draw for each dose. Adding more water makes measuring smaller doses easier but requires drawing larger volumes per injection.

Can I travel with reconstituted peptides?

Reconstituted peptides must remain refrigerated. For short trips, use an insulated cooler bag with ice packs. For air travel, check the regulations for your departure and arrival countries — many peptides have different legal statuses across jurisdictions.

Next Steps

Once your peptide is reconstituted, learn the proper injection technique in our guide: How to Inject Peptides.

Use our Dosage Calculator to determine the correct dose based on your body weight and the peptide you are using.