Dosing
Calculator.
Calculate exact reconstitution ratios with clinical accuracy. Ensure your research protocols are met with mathematical certainty.
Volume to Pull
Syringe Units (100u / 1ml)
* Based on standard volumetric Reconstitution. Always double-check calculations before administration.
How Peptide Reconstitution Works
Most research peptides are supplied as lyophilised (freeze-dried) powder in sealed vials. Before use, the powder must be reconstituted by adding bacteriostatic water — a sterile saline solution preserved with 0.9% benzyl alcohol that prevents microbial growth. The calculator above converts your vial size, water volume, and target dose into an exact draw volume in millilitres and the equivalent units on a standard U-100 insulin syringe.
Understanding the Formula
The calculation is straightforward: Concentration (mg/mL) = Vial content (mg) ÷ Water added (mL). Once you know the concentration, divide your target dose (converted from mcg to mg) by the concentration to get the draw volume in mL. Multiply by 100 to get the equivalent units on a U-100 syringe (100 units = 1 mL).
Example: A 5 mg vial reconstituted with 2 mL bacteriostatic water yields a concentration of 2.5 mg/mL (2,500 mcg/mL). A 250 mcg dose requires 0.1 mL — which is 10 units on a U-100 syringe.
Frequently Asked Questions
Why use bacteriostatic water instead of regular sterile water?
Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth and allows a reconstituted vial to be stored for up to 28 days. Regular sterile water is single-use only — once opened, it should be discarded. For research protocols requiring repeated draws from the same vial, bacteriostatic water is standard.
What is a U-100 insulin syringe?
A U-100 syringe is calibrated for insulin that contains 100 units per mL. Because the unit scale on the syringe equals 0.01 mL per unit, it is ideal for measuring small peptide doses with precision. The calculator outputs both mL and U-100 units so you can use whichever scale is clearer.
How much bacteriostatic water should I add to my vial?
The amount of water you add determines the concentration. Adding more water creates a lower concentration, which means you will draw a larger, easier-to-measure volume for each dose. For a 5 mg vial, 2 mL is a common choice as it produces a 2,500 mcg/mL concentration that keeps individual doses above 0.05 mL — the practical minimum for accurate measurement.
How long does a reconstituted peptide vial last?
Reconstituted peptides stored in bacteriostatic water and kept refrigerated (2–8°C) generally remain stable for up to 4 weeks. Lyophilised (unreconstituted) vials, if kept sealed and stored correctly, can last 1–2 years. Always check the specific stability data for the peptide you are working with.
Is this calculator accurate for all peptides?
Yes — the maths is the same regardless of the peptide. Reconstitution is a simple dilution calculation based on mass and volume. The formula does not vary by peptide type. However, always verify your inputs: vial content is printed on the label in mg, and your target dose should come from a peer-reviewed protocol specific to the peptide.