Peptide Reconstitution Calculator

How Peptide Reconstitution Works

Most research and compounded peptides are shipped as a lyophilized (freeze-dried) powder in a sealed vial. Before use, you must reconstitute the powder by adding bacteriostatic water (BAC water) to create an injectable solution.

The amount of water you add determines the concentration of your solution, which in turn determines how much liquid you inject per dose.

The Basic Formula

Concentration = Peptide Amount (mcg) ÷ Water Added (mL)

Injection Volume = Desired Dose (mcg) ÷ Concentration (mcg/mL)

Example

• Vial contains: 5mg (5,000mcg) of BPC-157
• You add: 2mL of bacteriostatic water
• Concentration: 5,000mcg ÷ 2mL = 2,500mcg/mL
• Desired dose: 250mcg
• Injection volume: 250mcg ÷ 2,500mcg/mL = 0.1mL (10 units on an insulin syringe)

Understanding Insulin Syringe Units

Peptide injections use insulin syringes, which are marked in "units." One mL equals 100 units.

For comfort, most practitioners aim for injection volumes of 0.1-0.3 mL (10-30 units). If your calculated dose requires more than 0.5 mL, consider adding less BAC water to increase concentration.

How Much Bacteriostatic Water to Add

The amount of water is your choice. More water means a more dilute solution (larger injection volume per dose). Less water means a more concentrated solution (smaller injection volume).

Common Reconstitution Volumes

Choosing Your Volume

Add less water (more concentrated) if:

• You want smaller injection volumes
• You are injecting subcutaneously (smaller volumes are more comfortable)
• Your dose is relatively small compared to vial size

Add more water (more dilute) if:

• You want easier-to-measure doses (larger volumes on the syringe)
• You are dosing very small amounts where precision matters
• You prefer to avoid overly concentrated solutions

Step-by-Step Reconstitution Process

What You Need

• Peptide vial (lyophilized powder)
• Bacteriostatic water (BAC water with 0.9% benzyl alcohol)
• Insulin syringe (for measuring BAC water and for injection)
• Alcohol swabs

The Process

1. Clean the tops of both the peptide vial and BAC water vial with alcohol swabs
2. Draw BAC water into the syringe to your desired volume
3. Inject slowly into the peptide vial, directing the stream against the glass wall (not directly onto the powder)
4. Swirl gently — never shake. Peptides are fragile proteins that can be damaged by vigorous agitation
5. Wait for the powder to dissolve completely. This may take 1-5 minutes. If needed, gently roll the vial between your palms
6. Store the reconstituted vial in the refrigerator (36-46°F / 2-8°C)

Critical Mistakes to Avoid

• Never use sterile water instead of bacteriostatic water for multi-dose vials. BAC water contains a preservative (benzyl alcohol) that prevents bacterial growth
• Never shake the vial. Vigorous shaking can denature (damage) the peptide
• Never freeze reconstituted peptides
• Never inject BAC water directly onto the lyophilized powder — aim for the glass wall

Storage After Reconstitution

Reconstituted peptides degrade over time. If your dosing protocol means a vial will last more than 4 weeks, consider reconstituting with less water or using a smaller vial size.

Common Peptide Dosing Reference

Disclaimer: This calculator is for educational reference. Always follow the dosing instructions provided by your prescribing physician or compounding pharmacy.