TB-500 10 mg reconstituted with 0.5 mL
Concentration
20mg/mL
- Per insulin unit
- 200 mcg
- Solution in vial
- 50 u
- 5 mg draw
- 25 u
Math utility only — not medical advice. Not a recommended dose.
Units per dose at 20 mg/mL
Insulin syringes are graduated in hundredths of a millilitre, so units = mL × 100 on a U-100, U-50 or U-30 barrel alike.
| Dose | Volume | U-100 units | Fits | Doses per vial |
|---|---|---|---|---|
| 2 mg | 0.1 mL | 10 u | U-30 | 5 |
| 2.5 mg | 0.125 mL | 12.5 u | U-30 | 4 |
| 5 mg | 0.25 mL | 25 u | U-30 | 2 |
How this is calculated
1 · Concentration
10 mg ÷ 0.5 mL = 20 mg/mL
The peptide mass never changes — bacteriostatic water only sets how concentrated the solution is, and therefore how far the plunger travels.
2 · Volume for a 5 mg dose
5 mg ÷ 20 mg/mL = 0.25 mL
3 · Insulin units
0.25 mL × 100 = 25 units
Every unit on the barrel carries 200 mcg at this concentration, so misreading by one unit is a 200 mcg error.
See it on a real syringe
The interactive calculator draws this 20 mg/mL mix on a scaled U-100 barrel, shows when a draw lands exactly on a printed tick, and works backwards from a target dose to the water volume that makes it land cleanly.
Open the interactive calculator →Common questions
- How much bacteriostatic water for a 10 mg TB-500 vial?
- Adding 0.5 mL of bacteriostatic water to a 10 mg TB-500 vial yields 20 mg/mL — 200 mcg in every insulin unit. The reconstituted vial holds 50 units of solution in total.
- How many units is a 5 mg dose of TB-500 at 10 mg in 0.5 mL?
- 5 mg is 0.25 mL of this mix, which is 25 units on a U-100 insulin syringe (a U-30 barrel is enough).
- How many 5 mg doses does a 10 mg vial give?
- A 10 mg vial contains 2 full 5 mg doses. Using more or less bacteriostatic water changes the units you draw, never the number of doses in the vial.