Tool
Reconstitution calculator
The most-asked question in every peptide community, answered arithmetically. Pick a compound to preload realistic figures, or enter your own.
Draw to
0.5 mL · 5 mg/mL · 50 mcg per unit
Doses per vial
4
Vial lasts
4 wk
Arithmetic only. This tool converts a vial and a target dose into syringe units - it does not tell you what dose to take, and it cannot verify that the vial contains what the label claims.
How the maths works
Reconstitution is one division and one multiplication. The vial contains a fixed mass of peptide; adding bacteriostatic water gives it a concentration; the dose you want divided by that concentration gives a volume; and volume converts to syringe units at a fixed rate.
The rate is the part people get wrong. Insulin syringes are calibrated for U-100 insulin, where 100 units = 1 mL. That is true on a 30-unit syringe, a 50-unit syringe and a 100-unit syringe alike - the number in the name is how much the barrel holds, not a different scale.
How much water you add does not change your dose. It changes how many units you draw to get that dose. More water means a bigger, easier-to-read number on the barrel; less water means a smaller one. The peptide in the vial is fixed either way, which is why “how many mg did I inject” and “how many units did I draw” are only the same question once you know the concentration.
What it cannot do
This calculator assumes the vial contains what the label says. For unregulated material that assumption is doing enormous work - a vial labelled 10 mg that actually contains 6 mg produces a confidently wrong number here. See safety and sourcing for what independent testing does and does not establish.