Dosing tools

The GLP-1 calculator, in one place.

Three tools, one page: reconstitution math with a live syringe diagram, brand ↔ compounded equivalents for every common dose strength, and a week-by-week titration schedule generator.

How this works

Reconstitution is mixing dry peptide powder with bacteriostatic water to make it injectable. This tool tells you the exact number of units to draw on a standard insulin syringe to inject your target dose.

Step-by-step & definitions

Step by step

  1. 1Pick your peptide. It's just a tag — the math works the same regardless of which peptide is in the vial.
  2. 2Enter the vial size in mg. This is printed on the vial label (e.g., 5 mg, 10 mg).
  3. 3Enter how much bacteriostatic water you'll add. Common volumes are 1–3 mL. More water = more dilute = bigger draws on the syringe.
  4. 4Enter your target per-injection dose in mg. For example, 0.25 mg is a typical semaglutide starting dose.
  5. 5Read "Draw to" on the right. Pull the plunger to that unit mark on the recommended insulin syringe. The diagram below shows the fill line.

Quick example

5 mg vial + 2.5 mL bacteriostatic water = 2 mg/mL. For a 0.25 mg dose, draw to 12.5 units on a 30-unit insulin syringe.

Definitions

Reconstitution
Adding sterile liquid to dry peptide powder to make it injectable.
Bacteriostatic water (BAC water)
Sterile water with 0.9% benzyl alcohol that prevents bacterial growth, letting a reconstituted vial last several weeks refrigerated.
Concentration (mg/mL)
How much peptide is in each milliliter of solution. The same dose draws different units depending on concentration.
Insulin syringe (U-100)
A syringe calibrated so 100 units = 1 mL. "30-unit", "50-unit", and "100-unit" refer to total capacity.
Unit
A tick mark on a U-100 insulin syringe. 1 unit = 0.01 mL.
mg

Total milligrams of peptide in your vial

mL

Volume of BAC water you'll add to the vial

mg

The dose you want to inject each time

Concentration

2.00

mg/mL

Volume per dose

0.125

mL

Draw to

12.5

units

Recommended syringe

30-unit

(U-100 calibration)

Visual
0102030Draw to 12.5 units