Peptide dosing

The formulas

Every number the calculator shows comes from these four equations. All insulin syringes mark 0.01 mL per unit, so the same math works on a 30 U, 50 U, or 100 U syringe.

Interactive worked example

Change any number — every step below updates as you type.

Vial contents (mg)

Water added (mL)

Target dose (mg)

Step 1 · Concentration

15.00 mg ÷ 1.00 mL

15.00 mg/mL

Step 2 · Dose per unit

15.00 mg/mL × 0.01 mL

0.150 mg (150.0 mcg)

Step 3 · Units to draw

2.00 mg ÷ 0.150 mg/unit

13.33 units

Step 4 · Volume drawn

13.33 units × 0.01 mL

0.133 mL

1. Concentration of the vial

concentration = vial contents ÷ diluent volume

Divide the amount of peptide in the vial (in mg) by the volume of bacteriostatic water you add (in mL). The result is how many milligrams sit in each milliliter of solution.

15 mg vial + 1 mL water → 15 ÷ 1 = 15 mg/mL

2. Dose per single unit mark

mg per unit = concentration × 0.01 mL

Every unit mark on an insulin syringe — 30 U, 50 U, or 100 U — holds exactly 0.01 mL of liquid. Multiplying the concentration by 0.01 gives the dose delivered at each single unit.

15 mg/mL × 0.01 mL = 0.15 mg per unit (= 150 mcg per unit)

3. Units to draw

units to draw = target dose ÷ mg per unit

Divide the dose you want (in mg) by the dose per unit. That's how far to push the plunger. To get the volume instead, multiply the units by 0.01 mL.

2 mg ÷ 0.15 mg/unit = 13.33 units = 0.133 mL

4. Reverse: water for a target dose per unit

diluent volume = (vial contents × 0.01 mL) ÷ desired mg per unit

Work backwards from the dose you want at each unit mark. Multiplying the vial contents by 0.01 fixes the product of concentration and water volume, so dividing by your target per-unit dose gives exactly how much water to add.

(15 mg × 0.01) ÷ 0.1 mg/unit = 0.15 ÷ 0.1 = 1.5 mL of water

Reference notes

  • 1 mg = 1000 mcg — the calculator converts automatically when you switch units.
  • 1 unit = 0.01 mL on every insulin syringe, so a 30 U syringe holds 0.3 mL, a 50 U holds 0.5 mL, and a 100 U holds 1 mL.
  • The per-unit dose is identical on all three syringes — only the maximum volume (and so the largest measurable dose) differs.
  • mg per unit × 1000 gives micrograms per unit, useful when doses are small.

Disclaimer

Always verify these calculations with a qualified healthcare professional before relying on them.

This calculator is an educational and informational tool only. It performs arithmetic on the numbers you enter — it is not medical advice, and nothing here has been reviewed by a doctor or pharmacist.

Peptide compounds discussed in research contexts are not approved by the FDA for human use and are not evaluated for safety, purity, or dosing. Compounded or reconstituted solutions carry real risks: contamination, inaccurate concentration, and dosing errors.

Nothing on this site should be used to prepare, reconstitute, or administer any substance to yourself or anyone else. Always follow the prescription, product insert, and instructions of a licensed healthcare provider, and verify every calculation independently before acting on it.

Use of this tool is entirely at your own risk. No warranties are made as to the accuracy of any result, and its creators accept no liability for any outcome arising from its use.