Dosage calculator
Peptide Reconstitution Calculator: mg to mL and Units
Quick answer
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.
- Updated March 26, 2026
- Reviewed by PeptideUniv Research Team
- 2 sources
- Educational use · not medical advice
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.
On this page
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.
Example Peptide Calculations
Step-by-step worked examples using common vial sizes. Results are for illustrating the math only.
Example
5 mg vial + 2 mL BAC water, 0.5 mg dose
Given
- Vial
- 5 mg
- BAC water
- 2 mL
- Target dose
- 0.5 mg
Result
20 units
0.2 mL at 2.5 mg/mL
- Concentration: 5 ÷ 2 = 2.5 mg/mL
- Draw volume: 0.5 ÷ 2.5 = 0.2 mL
- U-100 units: 0.2 × 100 = 20 units
Example
10 mg vial + 2 mL BAC water, 1 mg dose
Given
- Vial
- 10 mg
- BAC water
- 2 mL
- Target dose
- 1 mg
Result
20 units
0.2 mL at 5 mg/mL
- Concentration: 10 ÷ 2 = 5 mg/mL
- Draw volume: 1 ÷ 5 = 0.2 mL
- U-100 units: 0.2 × 100 = 20 units
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 |
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.
Important
For educational and research purposes only. Not medical advice. Consult a licensed healthcare professional before making any medical or health-related decisions.
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.
Sources & references
This page was reviewed against standard sterile-dilution references and safe handling guidance. The formulas are universal concentration math, but storage windows and handling details still need to match the specific vial label you are using.
- DailyMed - BACTERIOSTATIC WATER injection, solutionOfficial labeling reference for benzyl alcohol content and multi-dose bacteriostatic water context.
- CDC Injection Safety - Medication VialsPractical handling guidance for vial use and medication preparation.
Reviewed by PeptideUniv Research Team · Updated March 26, 2026