Peptide Reconstitution Calculator: mg to mL and Units
To calculate peptide reconstitution, divide your target dose (mg) by the concentration (mg/mL). Concentration = vial mg ÷ BAC water mL. Then multiply the draw volume (mL) by 100 to get U-100 syringe units. This three-step formula applies to any peptide vial.
Example Peptide Dosage Table
Common vial and BAC water combinations with calculated concentration, draw volume, and U-100 syringe units. For education only — verify your vial label before use.
| Vial (mg) | BAC water (mL) | Concentration | Dose (mg) | Draw (mL) | U-100 units |
|---|---|---|---|---|---|
| 5 mg | 2 mL | 2.5 mg/mL | 0.5 mg | 0.2 mL | 20 units |
| 5 mg | 5 mL | 1 mg/mL | 0.5 mg | 0.5 mL | 50 units |
| 10 mg | 2 mL | 5 mg/mL | 1 mg | 0.2 mL | 20 units |
| 10 mg | 10 mL | 1 mg/mL | 1 mg | 1 mL | 100 units |
How to Calculate Peptide Dosage
Three steps convert any vial and BAC water combination into the exact volume to draw on a U-100 insulin syringe.
Step 1 — Calculate concentration (mg/mL)
Divide the total peptide in the vial (mg) by the volume of BAC water you added (mL). For example: a 5 mg Peptide vial reconstituted with 2 mL BAC water gives 5 ÷ 2 = 2.5 mg/mL.Step 2 — Calculate draw volume (mL)
Divide your target dose (mg) by the concentration (mg/mL). For a 0.5 mg dose at 2.5 mg/mL: 0.5 ÷ 2.5 = 0.2 mL. This is the exact volume to draw into the syringe.Step 3 — Convert to U-100 syringe units
Multiply the draw volume (mL) by 100. For 0.2 mL: 0.2 × 100 = 20 U-100 units. Read this number on the unit markings of a standard insulin syringe.
Dosage Formula
Concentration formula
Concentration (mg/mL) = Vial mg ÷ BAC water mLDraw volume formula
Draw volume (mL) = Dose (mg) ÷ Concentration (mg/mL)U-100 syringe units
U-100 units = Draw volume (mL) × 100These three formulas apply to any Peptide vial, regardless of size. U-100 is the standard insulin-syringe scale: 100 units = 1 mL.
Peptide Calculator Tool
Enter your vial strength, BAC water volume, and target dose below. The calculator outputs concentration (mg/mL), draw volume (mL), and U-100 units. Educational and research use only.
Example Peptide Calculations
Step-by-step worked examples using common vial sizes. Results are for illustrating the math only.
5 mg vial + 2 mL BAC water, 0.5 mg dose
- Vial: 5 mg | BAC water: 2 mL | Target dose: 0.5 mg
- Concentration: 5 ÷ 2 = 2.5 mg/mL
- Draw volume: 0.5 ÷ 2.5 = 0.2 mL
- U-100 units: 0.2 × 100 = 20 units
10 mg vial + 2 mL BAC water, 1 mg dose
- Vial: 10 mg | BAC water: 2 mL | Target dose: 1 mg
- Concentration: 10 ÷ 2 = 5 mg/mL
- Draw volume: 1 ÷ 5 = 0.2 mL
- U-100 units: 0.2 × 100 = 20 units
Peptide Reconstitution Guide
Bacteriostatic water (BAC water) is the standard diluent for most research peptides. It contains 0.9% benzyl alcohol which inhibits microbial growth and extends the usable window of the reconstituted solution.
- Swab both the peptide vial stopper and the BAC water vial stopper with a fresh alcohol swab and allow to air dry.
- Draw the desired volume of BAC water into a sterile syringe.
- Insert the needle into the peptide vial and inject BAC water slowly along the glass wall — not directly onto the powder cake.
- Gently swirl the vial until the powder is fully dissolved. The solution should be clear and colourless. Do not shake.
- Store reconstituted peptides refrigerated at 2–8 °C. Most peptides are stable for 4–6 weeks after reconstitution under refrigeration.
Frequently Asked Questions
What is the peptide reconstitution formula?
Three formulas: (1) Concentration = vial mg ÷ BAC water mL. (2) Draw volume = dose mg ÷ concentration. (3) U-100 units = draw volume × 100. Enter your values in the calculator above.
What are U-100 syringe units?
U-100 is the standard scale for insulin syringes. 100 units = 1.0 mL. That means 10 units = 0.1 mL, 50 units = 0.5 mL. Multiply any draw volume in mL by 100 to get the U-100 units reading.
Do I need to recalculate if I change the amount of BAC water?
Yes. Changing BAC water volume changes the concentration (mg/mL), which changes the draw volume for the same mg dose. Always recalculate using: concentration = vial mg ÷ BAC water mL, then draw volume = dose mg ÷ concentration.
How do I convert mcg to mg for the calculator?
Divide mcg by 1000 to get mg. For example: 250 mcg = 0.25 mg, 500 mcg = 0.5 mg, 1000 mcg = 1 mg. Enter the mg value in the calculator.
What is BAC water?
Bacteriostatic water (BAC water) is sterile water with 0.9% benzyl alcohol added. The benzyl alcohol prevents bacterial growth, which extends the usable life of a reconstituted peptide solution compared to plain sterile water.
How long is a reconstituted peptide good for?
Most research peptides are stable for 4–6 weeks refrigerated after reconstitution with BAC water. Stability varies by compound. Store at 2–8 °C and discard if the solution becomes cloudy or discoloured.
Learn More
Research review and sources
Primary references and supporting sources
- DailyMed - BACTERIOSTATIC WATER injection, solution — Official labeling reference for benzyl alcohol content and multi-dose bacteriostatic water context.
- CDC Injection Safety - Medication Vials — Practical handling guidance for vial use and medication preparation.
Full Calculator + Protocol Tracker
The PeptideUniv app includes the full reconstitution calculator, dosing schedules, cycle tracker, and reminders — all in one place.
Open full calculator → · Start free trial →For educational and research purposes only. Not medical advice. Consult a licensed healthcare professional before making any medical or health-related decisions.