Peptide Dosage Calculator
To convert a peptide dose from milligrams to syringe units, divide the dose in milligrams by the concentration in mg/mL to get the volume in millilitres, then multiply by the syringe scale — 100 for a U-100 syringe, 50 for U-50, 40 for U-40.
The formula
units = (dose mg ÷ concentration mg/mL) × syringe scale
The syringe scale is the number of units marked per millilitre. Most insulin syringes are U-100, meaning 100 units per mL. If you use a U-40 syringe, the same volume shows as fewer units, so the scale matters as much as the concentration.
Calculate your dose
Enter your vial and dose to see the units to draw.
- Concentration
- 2.5 mg/mL
- Volume to draw
- 0.1 mL
- Per unit
- 25 mcg
- Doses per vial
- 20
Worked examples
The same arithmetic applied to several vial strengths and doses.
0.25 mg from a 5 mg vial
10units
- Concentration
- 2.5 mg/mL
- Dose
- 0.25 mg
- Volume
- 0.1 mL
0.5 mg from a 5 mg vial
20units
- Concentration
- 2.5 mg/mL
- Dose
- 0.5 mg
- Volume
- 0.2 mL
1 mg from a 10 mg vial
20units
- Concentration
- 5 mg/mL
- Dose
- 1 mg
- Volume
- 0.2 mL
2.5 mg from a 30 mg vial
25units
- Concentration
- 10 mg/mL
- Dose
- 2.5 mg
- Volume
- 0.25 mL
Frequently asked questions
- How do I convert mg to units?
- Divide the dose in milligrams by the concentration in mg/mL, then multiply by 100 for a U-100 syringe. For example, 1 mg at 5 mg/mL is 0.2 mL, which is 20 units.
- Why do two people draw different units for the same dose?
- Because they reconstituted at different concentrations. A 10 mg vial in 1 mL gives 10 mg/mL, while the same vial in 4 mL gives 2.5 mg/mL. The same 1 mg dose is 10 units in the first case and 40 in the second.
- What if my syringe is U-40 instead of U-100?
- A U-40 syringe is marked at 40 units per millilitre, so a 0.1 mL volume reads as 4 units rather than 10. Always check the scale printed on the barrel before converting.
- How many doses will my vial give me?
- Divide the vial strength by your dose size. A 10 mg vial gives ten 1 mg doses, regardless of how much bacteriostatic water you added.
Related calculators
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