How to use the Reconstitution Calculator — three inputs, exact syringe mark
The Reconstitution Calculator turns three inputs — your vial dose, the volume of bacteriostatic water you’ll add, and the dose you want to draw — into the exact syringe-tick mark for your protocol. Three steps, no calculator app, no math errors at the bench.
Step 1 — Set the vial dose
Pick the unit (mcg / mg / IU) first. Most peptides we ship are dosed in mg — BPC-157 5 mg, GHK-Cu 50 mg, Retatrutide 10 mg. For something like a 100 IU somatostatin reference, use IU and the calculator converts to mg internally (it treats 1 IU = 1 mcg by default — verify against your compound’s spec sheet).
Use the preset chips (5 · 10 · 15 · 30 · 100) or type a custom amount. The “Vial dose” is the total amount of lyophilized compound in the vial before reconstitution.
Step 2 — Set the bacteriostatic water
How much BAC water you add determines the concentration — and concentration drives the draw volume. The chips offer 1 / 2 / 3 mL, which covers most 3 mL vials. Two general rules:
- Less water = higher concentration = smaller draw volume per dose. Use this when the dose is small (≤250 mcg) and you want a syringe mark that’s easy to read.
- More water = lower concentration = larger draw volume. Use this when the dose is large or you want more granular control over partial doses.
Step 3 — Set your desired dose
Type the amount you want to draw per administration. Pick the unit (mcg / mg / IU) — note that this is independent of the vial unit. You can have a 5 mg vial and want a 250 mcg dose; the calculator handles the conversion.
Read the output
Four numbers appear instantly on the right:
- Volume to draw — the actual mL pulled into the syringe. The headline number, gradient blue.
- Syringe mark — the IU tick on a standard U-100 insulin syringe (1 IU = 0.01 mL). This is what you’ll actually look at on the syringe barrel.
- Concentration — mg per mL after reconstitution. Useful for cross-checking against your lab’s protocol notes.
- Doses per vial — how many full doses the vial yields before it’s empty.
Sanity-check the math
The three formulas behind the result, in case you want to verify by hand:
concentration = vial_mg ÷ mL_watervolume_to_draw = desired_dose_mg ÷ concentrationIU_mark = volume_to_draw × 100(because U-100 insulin syringes scale 1 mL = 100 IU)
Open the Reconstitution Calculator →
Research use only. Figures are math, not dosing recommendations.