- Core inputs
- Vial mg + BAC water + dose
- Core outputs
- mg/mL, mL, syringe units
- Best for
- New vial setup
How peptide reconstitution math works
Reconstitution math starts with concentration. The total peptide in the vial is divided by the amount of diluent added, which tells you how much peptide is present in each mL.
Once concentration is known, the target dose is divided by that concentration to calculate the draw volume. Syringe units are then derived from the syringe scale.
- Concentration = total peptide / diluent volume
- Dose volume = target dose / concentration
- U-100 units = mL to draw x 100
5 mg vial with 2 mL BAC water example
A 5 mg vial contains 5,000 mcg total. If you add 2 mL of diluent, the concentration is 2,500 mcg/mL.
At that concentration, a 250 mcg target dose is 0.1 mL. On a U-100 syringe, 0.1 mL equals 10 units.
- 5 mg = 5,000 mcg
- 5,000 mcg / 2 mL = 2,500 mcg/mL
- 250 mcg / 2,500 mcg per mL = 0.1 mL = 10 U-100 units
10 mg vial with 2 mL BAC water example
A 10 mg vial contains 10,000 mcg total. Mixed with 2 mL, the concentration is 5,000 mcg/mL.
At that concentration, a 500 mcg target dose is 0.1 mL, which is 10 units on a U-100 syringe. A 250 mcg target dose would be 0.05 mL, or 5 U-100 units.
- 10 mg = 10,000 mcg
- 10,000 mcg / 2 mL = 5,000 mcg/mL
- 500 mcg / 5,000 mcg per mL = 0.1 mL = 10 U-100 units
Why do peptide calculators give different answers?
A common frustration is entering the same vial and dose into two calculators and getting two results. It usually is not a bug — it is that one tool assumes a different diluent volume, a different syringe scale (U-100 vs U-40), or rounds the draw to the nearest unit while the other does not.
Concentration itself is not ambiguous: total peptide divided by diluent volume is fixed. Disagreements come from the assumptions layered on top. This calculator shows the concentration, the exact mL, and the syringe units side by side so you can see which assumption a different tool made, rather than trusting a single rounded number.
- Same vial + same dose should give the same concentration — always
- Differences trace to diluent volume, syringe scale, or rounding
- Check the syringe type (U-100 has 100 units/mL) before comparing units
When to use this calculator
Use this page before the first draw from a newly mixed vial or whenever vial strength, water volume, target dose, or syringe type changes.
If you already know the concentration and only need mL or units for a dose, the peptide dose calculator is the more direct tool.
Powder medication reconstitution video
Source: Level Up RN
Video notes
- Check the product instructions before adding diluent.
- Add liquid carefully and mix according to the medication directions.
- After the vial is mixed, concentration math is still needed before interpreting syringe units.