Reconstitution math without the guesswork

Reconstitution is where a lot of otherwise careful protocols go sideways. You’ve got a vial of lyophilized peptide measured in milligrams and a dose you want in micrograms or units. The mixing water is the variable you control.

The one relationship to remember

Concentration = amount in the vial ÷ water you add. Put 2 mL of bacteriostatic water into a 5 mg vial and you have 2.5 mg/mL, or 2500 mcg/mL. Add 1 mL instead and the same vial is twice as concentrated.

Your syringe then reads in units (a 1 mL insulin syringe is 100 units). At 2500 mcg/mL, each 10-unit mark is 250 mcg. Want a 300 mcg dose? That’s 12 units. The arithmetic is trivial once the concentration is fixed — the mistakes come from doing it in your head at 11 pm.

Let the app hold the numbers

Autus stores the vial size, the water you added, and the resulting concentration, then converts your target dose to syringe units for you. Change the reconstitution and every future dose updates. It also deducts from the vial as you log, so you know when you’re running low before you’re actually out.

Measure twice, inject once — but let the app do the measuring.