Peptide Calculator — Reconstitution, Dosage & Syringe Units

Peptide Calculator

Reconstitution · Dosage · Syringe units

Enter your vial size, the bacteriostatic water you added, and your target dose to get the exact syringe units to draw — plus concentration and doses per vial. Runs entirely in your browser; nothing you type is sent anywhere.

The calculator

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Units to draw are identical on any size — a smaller barrel just spreads the same draw across more length, making it easier to read.
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Volume
Concentration
Doses per vial
Enter a vial amount, water volume, and target dose — all greater than zero.
This draw is larger than your selected syringe’s capacity. Pick a larger barrel or reconstitute with less water.
This draw is under 2 units on a 100-unit barrel — try a smaller barrel size, or reconstitute with less water for a more readable mark.
Fill line reflects 0 units on a 100-unit barrel

Reconstituting your vial

Reconstitution is adding liquid — almost always bacteriostatic water — to a freeze-dried (lyophilized) peptide so it can be measured and injected.

  1. Clean both stoppers. Wipe the bacteriostatic water vial and the peptide vial with alcohol before puncturing either one.

  2. Draw the water first. Pull the intended amount of bacteriostatic water into a syringe before adding anything to the peptide vial.

  3. Add the water slowly. Aim the stream down the inside wall of the vial rather than directly onto the powder.

  4. Swirl gently. Roll or swirl the vial until the powder fully dissolves — avoid shaking it hard.

  5. Refrigerate after mixing. Keep the reconstituted vial cold and out of direct light unless the product labeling says otherwise.

How the math works

The peptide dissolves evenly through the water you add, so concentration is just milligrams divided by millilitres. Insulin syringes are graduated so 100 units equal 1 mL — that fixed ratio is what turns a volume into a plunger reading.

Concentration (mg/mL) = vial mg ÷ water mL
Units to draw = (target mcg ÷ (vial mg × 1000)) × water mL × 100
Doses per vial = (vial mg × 1000) ÷ target mcg, rounded down
Example: a 5 mg vial reconstituted with 2 mL of water is 2.5 mg/mL — 25 mcg per unit. A 250 mcg dose works out to 10 units on a U-100 syringe (0.10 mL), and the vial holds 20 such doses.

Common reconstitution ratios

Starting points for the arithmetic, not dosing recommendations — set your own numbers with a clinician. Click a row to load it into the calculator above.

CompoundVialBAC waterConcentrationExample dose → units
BPC-1575 mg2 mL2.5 mg/mL250 mcg → 10 units
TB-50010 mg3 mL3.3 mg/mL2 mg → 60 units
Ipamorelin5 mg2 mL2.5 mg/mL200 mcg → 8 units
CJC-12952 mg2 mL1 mg/mL100 mcg → 10 units
Sermorelin5 mg2 mL2.5 mg/mL200 mcg → 8 units
Tesamorelin10 mg2 mL5 mg/mL1 mg → 20 units
These figures illustrate the arithmetic only. They are not recommendations for any specific compound, dose, or protocol.

FAQ

It’s the step of adding liquid — almost always bacteriostatic water — to a freeze-dried (lyophilized) peptide so it becomes an injectable solution you can measure in units.

Sterile water with a small amount of benzyl alcohol added as a preservative, which stops bacterial growth — that’s what allows a reconstituted vial to be used across multiple doses over several weeks in the fridge.

The vial always holds the same total peptide. Spreading it through more water means each dose occupies more volume — and more syringe units — even though the actual dose hasn’t changed. It changes the measurement, not the amount delivered.

Pick by barrel size — 1 mL (100-unit), 0.5 mL (50-unit), or 0.3 mL (30-unit). All three use the same U-100 scale, so a given dose is the same number of units on any of them; a smaller barrel just spreads that draw across more length, which can make it easier to read precisely.

Round to the nearest mark you can read reliably, try a smaller-barrel syringe, or reconstitute with a different water volume so the dose lands on an easier line. Confirm any change with a healthcare professional.

Refrigerated around 2–8°C, most stay stable for roughly a few weeks, though this varies by compound. Keep the vial cold, protect it from light, and follow the specific storage guidance for whatever you’re working with.

No. It converts numbers you already have into syringe units — it doesn’t set a dose, confirm anything is appropriate for you, or replace a clinician.

For general education only — not medical advice or a treatment recommendation. This tool performs arithmetic on the numbers you enter; it does not evaluate, endorse, or recommend any substance, dose, or protocol. Talk to a qualified healthcare professional before you start, stop, or change anything.
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