Peptide Calculator

Work out reconstituted concentration, the volume to draw, and insulin-syringe units from a peptide vial's strength, the water added, and your dose in micrograms.

Quick Facts

Core formula
mcg/mL = (vial mg / water mL) x 1000
Converts a vial's milligram strength into a mcg-per-mL solution once reconstituted.
Syringe scale
U-100 = 100 units per mL
Insulin syringe markings use a 100-unit-per-mL scale no matter what the syringe's total capacity is.

Your Results

Calculated
Reconstituted concentration
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Peptide per mL of solution
Volume to draw
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mL for this dose
Syringe units to draw
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IU on the U-100 scale
Doses per vial
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Full injections from this vial

Ready

Enter the vial strength, water added, and desired dose, then calculate.

About this peptide calculator

This tool performs the standard reconstitution-and-dosing arithmetic used when a lyophilized peptide vial is mixed with bacteriostatic or sterile water. It converts the vial's milligram strength and the water volume you add into a working concentration, then converts your desired microgram dose into a syringe volume and an insulin-syringe unit reading. It does not tell you what dose, peptide, or schedule to use - it only does the math on the numbers you provide.

How the calculation works

Reconstitution follows three linked steps:

  • Concentration: divide the peptide amount in the vial (mg) by the water volume added (mL) to get mg/mL, then multiply by 1000 to get mcg/mL - the unit most peptide doses are written in.
  • Volume to draw: divide the desired dose (mcg) by the concentration (mcg/mL) to get the volume in mL you need to draw into the syringe.
  • Syringe units: U-100 insulin syringes are marked on a scale of 100 units per mL regardless of the syringe's total capacity, so multiplying the draw volume by 100 converts it into the units (IU) marked on the barrel.

Dividing the vial's total content (mg converted to mcg) by the dose per injection gives the number of full doses the vial can supply before it is used up.

Interpreting the result

  • The calculation assumes the powder contributes negligible volume, so the reconstituted solution volume is treated as equal to the water added - a standard simplification, not an exact measurement.
  • If the volume needed for one dose exceeds the total water added, the vial cannot supply that dose in a single draw at the chosen dilution; adding more water or lowering the dose changes the numbers.
  • If the units needed exceed a syringe's marked capacity, a larger syringe or a more concentrated reconstitution (less water) brings the draw within range.

Important disclaimer

This calculator performs arithmetic only. It is not a source of dosing, safety, or medical advice, does not verify peptide identity or purity, and does not replace guidance from a licensed healthcare provider or pharmacist.

Frequently Asked Questions

How is peptide reconstitution concentration calculated?
Concentration equals the peptide amount in the vial divided by the volume of bacteriostatic or sterile water added. Dividing milligrams by milliliters gives mg/mL; multiplying that by 1000 converts it to mcg/mL, which is the unit most injectable doses are written in.
How do I convert a mcg dose into insulin syringe units?
First find the volume to draw: desired dose in mcg divided by the concentration in mcg/mL gives the volume in mL. U-100 insulin syringes are marked on a scale of 100 units per mL, so multiplying that volume by 100 gives the number of units (IU) to draw, regardless of the syringe's total capacity.
How many doses are in one vial?
Convert the total vial amount from mg to mcg by multiplying by 1000, then divide by the mcg dose used per injection. This gives the number of full doses the reconstituted vial can supply before it runs out.

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