Research Tools
Reconstitution Calculator
Enter your vial size, how much bacteriostatic water you're adding, and your syringe type. The calculator will show your solution concentration and a reference table of draw volumes for a range of doses.
What You'll Need
💊
Peptide vial
Lyophilised (freeze-dried) powder. Check the label for the total mg content.
💧
Bacteriostatic water
0.9% benzyl alcohol solution. Preserves the solution after reconstitution. Do not use plain sterile water.
💉
Insulin syringe
U-100 insulin syringes are standard. Available in 0.3 mL, 0.5 mL, and 1 mL barrel sizes.
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Refrigerator
Store reconstituted peptides at 2–8°C. Most remain stable for 4–6 weeks when refrigerated.
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Alcohol swabs
Wipe the rubber septum of both vials before each use.
Quick Reference — How Much BAC Water to Add
Standard reconstitution volumes by vial size — click any row to pre-fill the calculator
| Vial size | Recommended BAC water | Concentration | 1 unit (U-100) = | Best for doses of | Notes |
|---|---|---|---|---|---|
| 2 mg | 1 mL | 2,000 mcg/mL | 20 mcg | 100 – 500 mcg | Semax, Selank, DSIP, small-dose peptides |
| 5 mg | 1 mL | 5,000 mcg/mL | 50 mcg | 500 mcg – 2 mg | Higher-dose protocols; each unit = 50 mcg |
| 5 mg | 2 mL | 2,500 mcg/mL | 25 mcg | 250 mcg – 1 mg | Easier measurement for smaller doses (e.g. 250–500 mcg) |
| 10 mg | 2 mL | 5,000 mcg/mL | 50 mcg | 500 mcg – 2 mg | BPC-157, TB-500, CJC-1295 — standard protocol |
| 15 mg | 3 mL | 5,000 mcg/mL | 50 mcg | 500 mcg – 2 mg | Thymosin Alpha-1, Epithalon, larger vials |
| 20 mg | 2 mL | 10,000 mcg/mL | 100 mcg | 0.5 – 2 mg | Retatrutide — 1 unit = 100 mcg (0.1 mg) |
| 30 mg | 3 mL | 10,000 mcg/mL | 100 mcg | 0.5 – 2 mg | Retatrutide large vial — 1 unit = 100 mcg |
| 50 mg | 5 mL | 10,000 mcg/mL | 100 mcg | 0.5 – 2 mg | High-volume research vials |
Click any row to pre-fill the calculator below with those values.
Calculator
1
Peptide vial size
The total amount of peptide in the vial, in milligrams (mg). Check the label.
mg
2
Bacteriostatic water to add
How many mL of BAC water you will inject into the vial. More water lowers the concentration — each unit on the syringe represents a smaller dose, making precise measurement of small amounts easier. 1–2 mL is standard for most peptides.
mL
3
Syringe type
Select the syringe you are using. This determines the scale shown in the reference table.
Your Reconstituted Solution
Solution concentration
—
mcg per mL
Each unit on syringe =
—
mcg per unit
Draw reference — volumes for common doses with this solution
| Dose | Units (U-100) | mL | Notes |
|---|
Step-by-step mixing instructions
- Wipe the rubber septum of your BAC water vial with an alcohol swab and allow to dry for 10 seconds.
- Draw — of bacteriostatic water into a sterile syringe.
- Wipe the rubber septum of your peptide vial with a fresh alcohol swab and allow to dry.
- Insert the needle at a 45° angle and inject the BAC water slowly down the inside wall of the vial — do not aim the stream directly at the powder cake.
- Gently swirl or roll the vial between your palms until the powder is fully dissolved. Do not shake or vortex.
- The solution should be clear and colourless. If it appears cloudy or has visible particles, do not use it.
- Label the vial with today's date and the concentration: —.
- Refrigerate at 2–8°C. Do not freeze the reconstituted solution. Use within 4–6 weeks.
Know your concentration — now work out your draw volume and vial requirements on the Dosage Calculator. Or explore pre-built multi-compound protocols on the Stack Builder.
The Formula
Concentration (mcg/mL) = Vial size (mg) × 1,000 ÷ BAC water added (mL)
mL to draw = Desired dose (mcg) ÷ Concentration (mcg/mL)
Units to draw (U-100) = mL to draw × 100
A U-100 insulin syringe has 100 units per mL — so 1 unit = 0.01 mL. Adding more BAC water lowers the concentration, spreading each dose across more units on the syringe barrel and making precise measurement of small doses easier.
Frequently Asked Questions
Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol. The benzyl alcohol acts as a preservative, inhibiting bacterial growth in the vial after it has been opened. This is critical for multi-use vials — plain sterile water has no preservative and should only be used for single-dose applications.
The amount of BAC water determines the concentration of your solution. Adding 1 mL to a 5 mg vial gives 5,000 mcg/mL. Adding 2 mL gives 2,500 mcg/mL. More water = lower concentration = more units per dose = easier to measure small amounts precisely. For doses under 200 mcg, 2 mL is generally recommended.
U-100 refers to the calibration — designed for U-100 insulin (100 units per mL). On a U-100 syringe, each unit mark = 0.01 mL. They come in three barrel sizes: 0.3 mL (30 units), 0.5 mL (50 units), and 1 mL (100 units).
When reconstituted with bacteriostatic water and stored at 2–8°C, most peptides remain stable for 4–6 weeks. Lyophilised peptides in sealed vials can be stored frozen (−20°C) for 12–24 months. Once reconstituted, never refreeze. Always label your vial with the reconstitution date.
Research use only. This calculator is provided for educational and reference purposes. All PEPNERD products are sold strictly for in-vitro scientific research and are not intended for human or veterinary use.