Reading time: ~2 min · Part of the free certification in peptide science
Concentration calculation is simple arithmetic, but an error here invalidates all later work. The basic relationship is:
Concentration = peptide mass ÷ diluent volume.
Reconstituting a 5 mg vial with 2 mL gives 5 ÷ 2 = 2.5 mg/mL (= 2500 mcg/mL).
The step that generates the most errors is translating a target amount into a volume to draw, because of the change of units: 1 mg = 1000 mcg. With the solution above (2500 mcg/mL), a target amount of 250 mcg requires: 250 ÷ 2500 = 0.1 mL.
On insulin syringes, volume is read in "units": a U-100 syringe has 100 units per mL, so 0.1 mL = 10 units. Moving comfortably between mg, mcg, mL and units is a basic technical skill; above all, it helps you spot an absurd result before it turns into a real error.
NeoPeptidos includes a reconstitution calculator with an mg/mcg selector that automates the calculation. Mastering the underlying arithmetic lets you verify that the tool —and you— are not making mistakes.
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Go to the quiz →Educational content for scientific purposes. It distinguishes preclinical from clinical evidence and is not medical advice, diagnosis or a recommendation for use. NeoPeptidos products are sold labelled for research use only (RUO).