From a dose to a syringe reading
Your instructions give a dose as a mass, such as 250 mcg or 2 mg. Your syringe measures volume, in units. The bridge between them is the concentration of the solution you mixed, which depends on how much peptide was in the vial and how much water you added.
Units = dose (mcg) ÷ concentration (mcg/mL) × 100
mL = dose (mcg) ÷ concentration (mcg/mL)
The calculator above runs both steps and draws the result on a syringe. It also counts how many doses the vial holds, which helps you plan when you will need the next one.
Dose chart: units for common doses
Units to draw on a U-100 syringe for some common mixes. Use the calculator for any combination not shown.
| Dose | 5 mg + 2 mL | 10 mg + 2 mL | 10 mg + 3 mL | 5 mg + 1 mL |
|---|---|---|---|---|
| 100 mcg | 4 units | 2 units | 3 units | 2 units |
| 200 mcg | 8 units | 4 units | 6 units | 4 units |
| 250 mcg | 10 units | 5 units | 7.5 units | 5 units |
| 300 mcg | 12 units | 6 units | 9 units | 6 units |
| 500 mcg | 20 units | 10 units | 15 units | 10 units |
| 750 mcg | 30 units | 15 units | 22.5 units | 15 units |
| 1 mg | 40 units | 20 units | 30 units | 20 units |
| 2 mg | 80 units | 40 units | 60 units | 40 units |
Choosing the right syringe
- 0.3 mL (30 units): best for doses under 30 units. The markings are spread out, so small doses are easier to read. Many have half-unit lines.
- 0.5 mL (50 units): a middle ground, usually marked in single units.
- 1 mL (100 units): needed for larger volumes. Usually marked every 2 units, so odd numbers fall between lines.
See the syringe units chart for how each size is marked. If your dose lands on an awkward number, the BAC water calculator finds a water volume that makes it a round number of units.
Dosage calculator questions
How do I convert a peptide dose in mcg to units?
Divide the dose by the concentration in mcg per mL, then multiply by 100. For example, at 2,500 mcg/mL a 250 mcg dose is 250 ÷ 2,500 = 0.1 mL, and 0.1 × 100 = 10 units on a U-100 syringe.
My dose is in mg. Does that change anything?
Only the unit. Switch the dose box to mg, or multiply by 1,000 to get mcg (1 mg = 1,000 mcg). The calculator handles both.
Why does my result say it won't fit in the syringe?
The dose volume is larger than the syringe holds: more than 30 units for a 0.3 mL syringe, 50 for a 0.5 mL, or 100 for a 1 mL. Choose a bigger syringe, or ask your pharmacist whether a more concentrated mix (less water) is appropriate.
Can the calculator tell me what dose to take?
No. It converts a dose you already have into a syringe reading. Dosing decisions belong to your prescriber, pharmacist or the product documentation.