Peptide Reconstitution Calculator
Calculate reconstitution dilutions, bacteriostatic water ratios, solution concentrations, and exact syringe measurement tick marks.
| Total Doses per Vial | 20 Full Doses |
| Volume per Dose | 0.10 mL (100 μL) |
| Total Vial Peptide Mass | 5,000 mcg (5.0 mg) |
| Reconstitution Liquid | 2.0 mL Bacteriostatic Water |
How Peptide Reconstitution & Dilution Works
Lyophilized (freeze-dried) peptides arrive as a stable dry powder cake inside a sterile sealed glass vial. Before laboratory handling or research use, the powder must be reconstituted into a liquid solution by adding Bacteriostatic Water (BAC Water) or sterile saline.
The exact amount of liquid added determines the concentration of the solution. Adding more water makes the solution more dilute (requiring more syringe units per dose), while adding less water makes it more concentrated.
The Mathematics of Peptide Reconstitution
Here are the step-by-step mathematical formulas for calculating concentration and syringe units:
Concentration (mcg/mL) = Total Micrograms / Water Added (mL)
Micrograms per 1 Syringe Unit = Concentration (mcg/mL) / 100 (for U-100)
Liquid Volume per Dose (mL) = Target Dose (mcg) / Concentration (mcg/mL)
Syringe Units to Draw = Liquid Volume per Dose (mL) * Syringe Factor (100 for U-100, 40 for U-40)
Total Doses per Vial = Total Micrograms / Target Dose (mcg)
Step-by-Step Worked Calculation Example
Suppose you have a 5 mg vial, add 2.0 mL of bacteriostatic water, and want a 250 mcg dose using a U-100 syringe:
- Convert mg to mcg:
5 mg * 1,000 = 5,000 mcg in vial. - Calculate concentration:
5,000 mcg / 2.0 mL = 2,500 mcg/mL. - Calculate dose volume:
250 mcg / 2,500 mcg/mL = 0.10 mL. - Convert volume to U-100 syringe units:
0.10 mL * 100 = 10 Units. - Total doses available in vial:
5,000 mcg / 250 mcg = 20 doses.
Master Peptide Reconstitution Reference Table
Syringe units required on a standard U-100 syringe across common vial sizes and dilution volumes:
| Vial Size (mg) | BAC Water Added (mL) | Concentration (mcg/mL) | 100 mcg Dose | 250 mcg Dose | 500 mcg Dose | 1,000 mcg (1mg) Dose |
|---|---|---|---|---|---|---|
| 2 mg | 1.0 mL | 2,000 mcg/mL | 5 Units | 12.5 Units | 25 Units | 50 Units |
| 2 mg | 2.0 mL | 1,000 mcg/mL | 10 Units | 25 Units | 50 Units | 100 Units |
| 5 mg (Default) | 2.0 mL | 2,500 mcg/mL | 4 Units | 10 Units | 20 Units | 40 Units |
| 5 mg | 3.0 mL | 1,667 mcg/mL | 6 Units | 15 Units | 30 Units | 60 Units |
| 10 mg | 2.0 mL | 5,000 mcg/mL | 2 Units | 5 Units | 10 Units | 20 Units |
| 10 mg | 3.0 mL | 3,333 mcg/mL | 3 Units | 7.5 Units | 15 Units | 30 Units |
| 15 mg | 3.0 mL | 5,000 mcg/mL | 2 Units | 5 Units | 10 Units | 20 Units |
Understanding Syringe Volume & Unit Markings
- U-100 1.0 mL Syringe (100 Units): Standard size with 1-unit markings up to 100 units. Best for doses requiring 30 to 100 units.
- U-100 0.5 mL Syringe (50 Units): Features wider, easier-to-read tick marks up to 50 units. Ideal for precise smaller volume measurements.
- U-100 0.3 mL Syringe (30 Units): Features half-unit tick marks for ultra-fine micro-dosing.
- U-40 Veterinary Syringe (40 Units/mL): Contains 40 units per 1.0 mL. 1 unit equals 0.025 mL.
5 Critical Safety & Handling Protocols for Peptides
Frequently Asked Questions
First, convert vial milligrams to micrograms (mg * 1000). Divide total micrograms by milliliters of water added to find concentration in mcg/mL. Then divide your target dose by the concentration and multiply by 100 to find the syringe tick mark units on a U-100 syringe.
Sterile water contains no preservatives and must be used immediately in a single use. Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits microbial growth and allows safe multi-dose refrigeration for up to 30 days.
1 milligram (mg) equals exactly 1,000 micrograms (mcg or μg). For example, 5 mg equals 5,000 mcg; 0.25 mg equals 250 mcg.
Generally no. Repeated freeze-thaw cycles break peptide molecular bonds. Unreconstituted dry powder can be frozen for long-term storage (-20°C), but reconstituted liquids should only be refrigerated.
A properly reconstituted peptide solution should be crystal clear. If the liquid remains cloudy, discolored, or contains visible floating particles, the peptide may be denatured or contaminated and should not be used.