Tools

Peptide Concentration Calculator

Enter the total peptide content and diluent volume to find the concentration in mg/mL, mcg per syringe unit, and units per mg. Includes a worked dose example.

Quick presets

Total peptide in vial

Total liquid volume

Syringe units per mL

IU/mL

Example dose (for worked example)

mcg

Concentration

2.50

mg/mL

Per syringe unit

25.0

mcg/unit

mg per unit

0.0250

mg/unit

Units per 1 mg

40.0

units (U-100)

Worked example

To draw 250 mcg (0.25 mg) from this solution, draw 10.0 units (0.1000 mL) on a U-100 syringe.

This vial yields 20 total doses at this dose size.

Show the math›

Concentration: 5 mg ÷ 2 mL = 2.5000 mg/mL

mg per unit: 2.5000 mg/mL ÷ 100 IU/mL = 0.025000 mg/unit

mcg per unit: 0.025000 mg × 1000 = 25.00 mcg/unit

Units per 1 mg: 100 IU/mL ÷ 2.5000 mg/mL = 40.00 units

Example: 250 mcg ÷ 1000 = 0.250 mg

0.250 mg × 40.00 units/mg = 10.00 units

10.00 units ÷ 100 IU/mL = 0.1000 mL

Doses in vial: floor(5 mg × 1000 ÷ 250 mcg) = 20

Assumptions

Default syringe type is U-100 (1 mL = 100 units) — the standard for peptide injections
Concentration assumes the peptide is fully dissolved and evenly distributed
Total mL is the amount of diluent added (bacteriostatic water, sterile water, etc.)
Does not account for vial overfill or dead volume in syringes

How This Calculator Works

Flow diagram showing how the concentration calculator works — Concentration calculation flow — from vial contents to mcg per unit

The calculator divides the total peptide (mg) by the total liquid volume (mL) to produce the concentration in mg/mL. It then derives mg per syringe unit and its inverse (units per mg) for your chosen syringe type. The worked example converts a sample dose through the full chain: mcg → mg → units → mL.

Assumptions & Limitations

Assumes the peptide is fully dissolved and evenly distributed in solution after reconstitution.
Total mL is the amount of diluent you added (bacteriostatic water, sterile water, etc.) — not including any vial overfill.
Default syringe type is U-100 (100 units = 1 mL). Change this if you use a U-40 or U-50 syringe.
Preset reconstitution volumes are common conventions — your actual volume may differ based on your protocol.

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Guides

Dosage & protocol guides
Peptide-specific dosing and cycle references.

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Frequently Asked Questions

How do I calculate peptide concentration?

Divide the total peptide content (in mg) by the total liquid volume (in mL). For example, 5 mg of BPC-157 reconstituted with 2 mL of bacteriostatic water gives a concentration of 5 / 2 = 2.5 mg/mL.

What does "mcg per unit" mean?

It tells you how many micrograms of peptide are in one syringe unit. For a U-100 syringe at 2.5 mg/mL concentration, each unit contains 25 mcg. This number is crucial for accurate dosing — it connects your desired dose to a physical mark on the syringe.

What is a U-100 syringe?

A U-100 insulin syringe is calibrated so 100 units = 1 mL. It is the standard syringe type for peptide injections. Other types exist (U-40, U-50) but are uncommon for peptides. This calculator defaults to U-100 but supports other types.

Does adding more bacteriostatic water change the concentration?

Yes. More diluent = lower concentration = more volume to draw per dose. For example, 5 mg in 1 mL = 5 mg/mL, but 5 mg in 2 mL = 2.5 mg/mL. Lower concentrations make it easier to measure small doses accurately.

Educational Use Only

This calculator is provided for educational and informational purposes. It is not medical advice. Always verify your reconstitution math independently and consult a healthcare provider for dosing guidance.

Last reviewed: February 2026