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HCG Reconstitution Calculator

Reconstitution in units rather than milligrams. The label Prof. Peptide read supplies HCG as a lyophilized powder of 10,000 USP units per multiple-dose vial; a water volume and a dose in units give the draw volume and the mark it reaches.

Last reviewed: September 21, 2026

A vial of N USP units, a water volume and a dose in USP units give the mark on the syringe. The unit cancels, so no mass conversion is involved.

Read it off the vial. Strengths Prof. Peptide has read from a label: 10000 USP units.

How reconstitution math works for HCG

HCG ships as a lyophilized (freeze-dried) powder, labelled in USP units rather than milligrams. Reconstituting it — dissolving the powder in bacteriostatic water — does not change the total USP units in the vial; it sets the concentration, which determines what a given dose reads as on a syringe:

  • Draw volume (mL) = (dose in USP units ÷ vial strength in USP units) × water volume (mL)
  • Syringe units = draw volume (mL) × 100, on a U-100 insulin syringe

No milligram field appears anywhere in this calculation — HCG’s USP unit has no established mg equivalent this page states, unlike somatropin’s WHO-defined 3.0 IU-per-mg conversion, which belongs to a different hormone entirely.

Worked example

A 10,000 USP unit vial reconstituted with 2 mL of bacteriostatic water, for a 500 USP unit dose:

Draw volume(500 ÷ 10,000) × 2 mL = 0.1 mL
Syringe units0.1 mL × 100 = 10 units

Enter the same three numbers into the calculator above and it returns the same figures.

What changes the answer

  • Water volume. More water lowers the concentration and raises the syringe-unit count for a fixed USP-unit dose; less water does the reverse — the vial’s total USP-unit content never changes.
  • Vial strength. 10,000 USP units is the strength Prof. Peptide has read on a label; other strengths can be entered directly.

FAQ

How do I reconstitute HCG?
Prof. Peptide's labelled reference is a 10,000 USP unit vial of lyophilized HCG powder, reconstituted with bacteriostatic water. The mass of HCG in the vial does not change with the water volume — what changes is the concentration, and therefore how many syringe units a given USP-unit dose reads as. This page reports that arithmetic; how much water to add is a choice it does not make.
hcg reconstitution calculator bacteriostatic water
This page's calculator takes a vial's strength in USP units, the volume of bacteriostatic water added, and a dose in USP units, and returns the draw volume and the mark it reaches on a U-100 syringe.
Does the water volume change how much HCG is in the vial?
No. A 10,000 USP unit vial contains 10,000 USP units of HCG regardless of the water volume used to reconstitute it. The water sets the concentration — units per mL — which is what determines the syringe reading for a given dose.
How many mL of bacteriostatic water do I add to a 10,000 unit HCG vial?
This page reports what a chosen water volume does to the concentration and the resulting syringe reading — it does not state a water volume to use, since that is a choice about the physical vial rather than arithmetic. Enter the volume you're using (or considering) into the calculator above to see what it produces.

For the general USP-units-to-syringe question without the reconstitution framing, see the HCG calculator.