Peptide reconstitution calculator
Enter your vial size, the BAC water you'll add, and your target dose. The calculator gives you the exact units to draw on a U-100 insulin syringe in real time.
Calculator
All calculations run locally in your browser. We don't see what you enter.
in mg
in ml
in mcg
in mg (alternative input)
Units to draw on U-100 syringe
10
Concentration: 2500 mcg/ml · 25 mcg per unit
How it works
- Concentration = (vial mg × 1000) / BAC ml = mcg per ml
- Per unit = concentration / 100 (because U-100 syringe = 100 units per ml)
- Units to draw = target dose / mcg per unit
Common reference setups
| Vial | BAC water | Concentration | 250 mcg dose | 500 mcg dose |
|---|---|---|---|---|
| 5 mg | 2 ml | 2500 mcg/ml | 10 units | 20 units |
| 5 mg | 3 ml | 1667 mcg/ml | 15 units | 30 units |
| 10 mg | 2 ml | 5000 mcg/ml | 5 units | 10 units |
| 10 mg | 3 ml | 3333 mcg/ml | 7.5 units | 15 units |
For semaglutide / tirzepatide (mg dosing)
GLP-1 compounds are dosed in mg, not mcg. Use the "Target dose (mg)" input. Example: 5 mg semaglutide vial + 2 ml BAC water:
- 0.25 mg starter dose = 10 units
- 0.5 mg dose = 20 units
- 1.0 mg dose = 40 units
Common mistakes
- Confusing mg with mcg. Most peptides dosed in mcg; GLP-1s in mg. 1000x error if mixed up.
- Wrong syringe scale. This calculator assumes U-100 (most common). U-40 syringes read differently.
- Dead space. Insulin syringes lose ~3-5 units in dead space. Negligible at high doses, meaningful at micro-doses.
Disclaimer
This calculator is provided for general informational purposes. It does not constitute medical advice. Always verify your dose with a healthcare professional. Peptide use carries risks; some peptides are not approved for human use in your jurisdiction.