Peptide Reconstitution Calculator

Peptide Reconstitution Calculator

Calculate the exact concentration, injection volume, and insulin syringe units for any reconstituted peptide.

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What Is Peptide Reconstitution?

Reconstitution is the process of dissolving a lyophilized (freeze-dried) peptide powder into an injectable solution using a sterile solvent. The most common solvent is bacteriostatic water (sterile water containing 0.9% benzyl alcohol as a preservative), which allows the reconstituted peptide to remain stable for multiple uses over several weeks.

The amount of solvent you add determines the concentration of the resulting solution, which in turn determines how much liquid you need to draw into the syringe for each dose.

How to Calculate Peptide Concentration

The formula is straightforward: divide the total peptide amount by the volume of water added.

Concentration (mg/mL) = Peptide Amount (mg) ÷ Water Volume (mL)

For example, dissolving a 5 mg vial in 2 mL of bacteriostatic water yields a concentration of 2.5 mg/mL. The same vial dissolved in 1 mL would yield 5 mg/mL — a more concentrated solution that requires less volume per dose.

Understanding Insulin Syringe Units

Most peptide injections use a standard U-100 insulin syringe, where 100 units equals 1 mL. This means:

1 unit = 0.01 mL

10 units = 0.1 mL

50 units = 0.5 mL

100 units = 1.0 mL

To calculate syringe units: divide your dose (in mg) by the concentration (in mg/mL), then multiply by 100. Or simply use the calculator above.

Common Reconstitution Examples

BPC-157

5 mg

2 mL

250 mcg

2.5 mg/mL

10

Semaglutide

500 mcg

20

Ipamorelin

2.5 mL

200 mcg

2.0 mg/mL

TB-500

2,500 mcg

100

CJC-1295

100 mcg

5

GHK-Cu

10 mg

5.0 mg/mL

Tips for Accurate Reconstitution

Inject water slowly along the inside wall of the vial — never squirt directly onto the powder, as this can damage the peptide.

Swirl gently to dissolve. Do not shake, as agitation can denature the peptide and reduce potency.

Store reconstituted peptides refrigerated at 2-8°C. Most remain stable for 3-4 weeks.

Use bacteriostatic water rather than sterile water for multi-use vials. The preservative prevents bacterial growth.

Use an alcohol swab to clean the vial stopper before each draw.

Frequently Asked Questions

Reconstitution is the process of dissolving a lyophilized (freeze-dried) peptide powder with a sterile solvent — typically bacteriostatic water — to create an injectable solution. The resulting concentration depends on how much water you add.

The amount of water determines your concentration. More water = lower concentration = more volume per dose. Common choices are 1-2 mL for smaller vials (5 mg) and 2-5 mL for larger vials (10-15 mg). Use whatever makes your dose easy to measure on your syringe.

On a standard U-100 insulin syringe, 100 units equals 1 mL. So 10 units = 0.1 mL, 50 units = 0.5 mL, and so on. This calculator converts your dose into these units so you know exactly how far to draw on the syringe.

If the calculated dose exceeds 100 units (1 mL), you'll need to either split the injection into two draws, use a larger syringe, or reconstitute with less water to increase the concentration.

1 mg = 1,000 mcg. So 250 mcg = 0.25 mg, and 500 mcg = 0.5 mg. This calculator accepts the dose in mcg (micrograms), which is the most common unit for peptide dosing.

Most reconstituted peptides remain stable for 3-4 weeks when stored refrigerated (2-8°C). Avoid freezing reconstituted solutions. Always use bacteriostatic water rather than sterile water, as the benzyl alcohol preservative helps prevent bacterial contamination.

Disclaimer: This calculator is for educational and informational purposes only. It is not medical advice. Always consult a qualified healthcare professional before using any peptide or injectable compound. Peptides are investigational compounds — verify all dosing with your prescriber.