Peptide concentration math, explained without the guesswork

Most reconstitution errors are unit errors. The vial is labeled in milligrams, the solution is described in milligrams per millilitre, the working amount is quoted in micrograms, and the syringe is graduated in units. Four scales, one vial.

From mg to mg/mL

Divide the vial mass by the diluent volume. 30 mg in 3 mL is 10 mg/mL. 10 mg in 2 mL is 5 mg/mL. Nothing else changes this number — the volume you add defines it permanently for that vial.

From mg/mL to mcg per 0.1 mL

One milligram is 1,000 micrograms. A 10 mg/mL solution therefore holds 10,000 mcg per mL, or 1,000 mcg per 0.1 mL. Working in tenths of a millilitre keeps the arithmetic readable at the bench.

From volume to syringe units

A U-100 syringe is graduated so that 100 units equal 1 mL. Ten units are 0.1 mL, five units are 0.05 mL. Converting a calculated volume into units is a straight multiplication by 100.

Let the calculator hold the numbers

• Pick a catalog vial preset or enter a custom mass.
• Enter the diluent volume you plan to add.
• Enter the target amount in micrograms.
• Read back concentration, mcg per 0.1 mL, the volume containing your target, and the equivalent U-100 units.

The calculator is a laboratory calculation aid for research materials. It is not dosing, administration, or medical guidance, and Opa Peptides products are supplied for research use only.