Peptide Calculator & Protocol Schedule
Work out the concentration of a reconstituted research vial, the volume that corresponds to a given measured amount, and how many preparations a vial yields. Calculations run entirely in your browser — plan entries stay in this browser, with optional device-local saving and calendar export.
02 / Calculated draw
Arithmetic from your entries. Confirm the product, concentration and syringe with your pharmacist or clinician before administration.
- Concentration
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- Amount per administration
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- Volume per administration
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- U-100 syringe marking
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- Whole administrations per vial
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- Remainder per vial
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Enter the vial, water and administration amounts to calculate.
Syringe capacity
Whole administrations exclude dead space, handling losses and expiry. A calculated quantity is not a guarantee of usable supply. No rounding to a nearby syringe mark is performed.
Protocol schedule
Schedule an existing prescribed or approved protocol. This tool cannot determine how often you can safely take a peptide. Frequency, dose, reconstitution, storage and discard instructions must come from the product label and your clinician or pharmacist.
04 / Your calendar
Complete your calculation and timing to build a schedule.
Calculations stay in this browser. Saving is optional and device-local. Calendar export creates a file; import it into your calendar and configure reminders there. PeptiDex does not send notifications.
| Date & time | Amount | Draw | Vial |
|---|
Measurement reference: FDA guidance on concentration, syringe size and mg/mL/unit conversion errors.
A separate worked example, step by step
This separate laboratory example uses a vial containing 5 mg of lyophilised peptide, reconstituted with 2 mL of bacteriostatic water.
- Concentration. 5 mg ÷ 2 mL = 2.5 mg/mL, which is 2,500 mcg/mL.
- Per syringe unit. A U-100 syringe divides 1 mL into 100 units, so one unit holds 2,500 mcg ÷ 100 = 25 mcg.
- Volume for a 250 mcg measured amount. 250 mcg ÷ 2,500 mcg/mL = 0.1 mL, which is 10 units on that syringe.
- Preparations per vial. 5,000 mcg ÷ 250 mcg = 20 preparations.
This is arithmetic on a laboratory preparation, shown as a unit-conversion reference. It is not medical advice, not a dosing recommendation, and not an instruction for human use.
How reconstitution maths works
Reconstitution is a dilution problem. A vial contains a fixed mass of lyophilised (freeze-dried) peptide. Adding a known volume of bacteriostatic water produces a solution whose concentration is simply mass divided by volume:
concentration (mg/mL) = peptide mass (mg) ÷ diluent volume (mL)
A 5 mg vial reconstituted with 2 mL of bacteriostatic water gives 2.5 mg/mL, or 2,500 mcg/mL. Because a U-100 insulin syringe divides 1 mL into 100 units, each unit on that syringe holds one hundredth of the per-millilitre concentration — 25 mcg in this example.
The volume corresponding to any measured amount then follows:
volume (mL) = target amount (mcg) ÷ concentration (mcg/mL)
Reconstitution and storage
Diluent type, final solution volume, preparation technique, storage and discard timing are product-specific. Follow the product label and your pharmacist’s instructions. This calculator does not establish whether bacteriostatic water is suitable for a compound or how long a prepared vial remains usable.
Changing the water volume changes concentration. The calculator assumes final solution volume equals water added unless you enter a label-specified final volume. Never change a prescribed preparation simply to make a syringe number more convenient.
A second worked example
A 10 mg vial reconstituted with 3 mL of bacteriostatic water yields 3.33 mg/mL (3,333 mcg/mL). On a U-100 syringe that is 33.3 mcg per unit. A 500 mcg target amount is therefore 0.15 mL, or 15 units, and the vial yields 20 such preparations.
Per-compound calculator pages
23 compounds have their own page: the same calculator, plus that compound's documented molecular weight for mass-to-molar reference and its own reconstitution and storage notes.
Related references
Storage & Handling Guide
Temperature, light protection, and stability windows for lyophilised and reconstituted material.
Bacteriostatic Water
What it is, how it differs from sterile water, and why it matters for multi-draw vials.
Glossary
Lyophilisation, reconstitution, half-life and the rest of the vocabulary.
Compare Peptides
Put two or three compounds side by side on class, mass, half-life and mechanism.