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Peptide Reconstitution Calculator

Turn a vial and a target dose into an exact syringe measurement — how much bacteriostatic water to add, how many units to draw, how many doses the vial holds and how long it keeps.

Your vial

As printed on the label.

Typical: 250–500 mcg

Typical: 1–2× daily

Draw this much

Per injection
10
units
= 0.1 mL on a U-100 syringe
0102030405060708090100
Fill to 10 units
Concentration
2.5 mg/mL
Per syringe unit
25 mcg
Doses in the vial
20
Lasts
20 days

This lands on a clean, readable part of the syringe and the vial is used up within its 28-day window.

Grade BBPC-157 · Subcutaneous or oral (gut-localized)

Studied extensively in animal models for tendon, ligament, muscle, and gut mucosal healing. Human evidence is limited to small clinical observations.

Full BPC-157 profile →

How the maths works

Reconstitution is one division and one unit conversion, but the unit conversion is where dosing errors happen. An insulin syringe is marked in units, not millilitres, and the relationship between the two depends entirely on how much water you added.

  1. 1

    Concentration

    Peptide mass ÷ water volume. A 5 mg vial with 2 mL of water is 2.5 mg/mL, or 2,500 mcg per mL.

  2. 2

    Micrograms per unit

    A U-100 syringe puts 100 units in 1 mL, so 2,500 mcg/mL is 25 mcg in every unit.

  3. 3

    Units to draw

    Target dose ÷ mcg per unit. A 250 mcg dose at 25 mcg/unit is 10 units — the first mark past the 5.

Adding more water does not weaken the dose

This is the point people get wrong most often. The vial holds a fixed mass of peptide whatever you dilute it with. More water means a lower concentration, so the same dose occupies more units on the syringe — which makes it easier to measure accurately, not weaker. If your dose works out to two or three units, adding water is the fix.

Calculate for a specific peptide

Educational only. Outputs are estimates for self-experimentation and discussion with a qualified clinician. Not medical advice or diagnosis. See medical disclaimer.