Try a common scenario
Tap a row below to see how the math works. Each scenario shows what a typical dose looks like on the syringe.
Concentration
2.50mg/mL
Draw volume
0.10mL
Insulin units
10IU
Doses per vial
20
U-100 insulin syringe
Draw to 10 IU mark
Your reconstitution recipe
- Vial size5 mg
- BAC water added2 mL
- Concentration2.50 mg/mL
- Dose per injection250 mcg
- Draw volume0.10 mL
- On U-100 syringe10 IU
- Doses per vial20
- Use by—
Step-by-step reconstitution
- Bring the vial to room temperature. Remove the 5 mg vial from cold storage and let it sit 15–20 minutes until it reaches 20–25°C / 68–77°F.
- Sanitize the stopper. Wipe the rubber stopper with a 70% isopropyl alcohol prep pad and let it air dry.
- Draw the BAC water. Using a sterile syringe, draw 2 mL of bacteriostatic water (0.9% benzyl alcohol).
- Inject slowly down the vial wall. Angle the needle against the inside of the vial — do not spray directly onto the lyophilized powder. This protects peptide structure.
- Swirl, don't shake. Gently swirl until fully dissolved into a clear, colorless solution. Discard if cloudy or discolored.
- Label and draw your dose. Mark the vial with today's date. Draw 0.10 mL (10 IU) for your 250 mcg dose.
- Refrigerate immediately. Store reconstituted solution at 2–8°C / 36–46°F. Use within 28–30 days. Never freeze a reconstituted solution.
Compare BAC water volumes
Less water = more concentrated solution = smaller injection volume. More water = easier to measure tiny doses accurately. Same dose, three options:
5.00 mg/mL
5 IU per dose
2.50 mg/mL
10 IU per dose
1.67 mg/mL
15 IU per dose
How long does one vial last?
Storage after reconstitution
Reference tables
Use these to sanity-check what the calculator shows you. The math is the same for any peptide — only the vial size, water volume, and dose change.
Table 1 — Concentration (mg/mL) for any vial + water combination
Read down to your vial size, across to the water volume you'll add. The cell shows your finished concentration.
| Vial size ↓ / Water → | 1 mL | 2 mL | 3 mL | 5 mL |
|---|---|---|---|---|
| 2 mg vial | 2.00 | 1.00 | 0.67 | 0.40 |
| 5 mg vial | 5.00 | 2.50 | 1.67 | 1.00 |
| 10 mg vial | 10.0 | 5.00 | 3.33 | 2.00 |
| 15 mg vial | 15.0 | 7.50 | 5.00 | 3.00 |
| 20 mg vial | 20.0 | 10.0 | 6.67 | 4.00 |
Table 2 — IU to draw on a U-100 syringe
Find your concentration on the left, then read across to your target dose. The cell is the IU mark to pull the plunger to.
| Conc. ↓ / Dose → | 100 mcg | 250 mcg | 500 mcg | 1 mg | 2 mg | 5 mg |
|---|---|---|---|---|---|---|
| 1.0 mg/mL | 10 | 25 | 50 | 100 | 200 ⚠ | 500 ⚠ |
| 2.5 mg/mL | 4 | 10 | 20 | 40 | 80 | 200 ⚠ |
| 5.0 mg/mL | 2 | 5 | 10 | 20 | 40 | 100 |
| 10 mg/mL | 1 | 2.5 | 5 | 10 | 20 | 50 |
⚠ = exceeds 100 IU. Either add more BAC water (lower the concentration) or split the dose into two injections.
Reference
How the math works
Concentration = vial (mg) ÷ water (mL). Draw volume = dose (mg) ÷ concentration. Insulin units = draw volume × 100 on a U-100 syringe. Doses per vial = vial (mg) ÷ dose (mg).
Why BAC water, not sterile water
Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth and allows multi-dose use from one vial. Sterile water has no preservative — safe only for single-use applications.
U-100 vs other syringes
U-100 means 100 insulin units per 1 mL. 10 IU = 0.10 mL. Most research peptide work uses U-100 because the markings are fine-grained enough to measure sub-millilitre doses accurately.
Choosing your water volume
Less water concentrates the solution (smaller draws, harder to measure tiny doses precisely). More water dilutes (larger draws, easier to read on syringe). 2 mL is the most common default.
For laboratory and research reference only. The information provided here is educational and is not medical advice. These compounds are sold for research use only and are not intended for human consumption, self-administration, or any therapeutic application. Always verify calculations independently and consult a qualified professional before handling research compounds.