Reconstitution Calculator
Reconstitution math and protocol planning for research peptides. Enter the vial amount, the volume of bacteriostatic water you plan to add, and the amount you need per administration. The calculator returns the exact draw in syringe units, shows it on a to-scale syringe diagram, and flags measurements too small to read accurately.
Dilution Parameters
Protocol Configuration
Protocol Forecast
Exports directly to Apple Calendar, Google Calendar, and Microsoft Outlook.
How the calculation works
Reconstitution is a dilution problem with three variables. Two are chosen; the third follows.
| Metric | Formula | Example |
| Concentration | $\text{peptide mass} \div \text{diluent volume}$ | A 10 mg vial in 2 mL of bacteriostatic water yields 5 mg/mL. |
| Volume per administration | $\text{target amount} \div \text{concentration}$ | A 250 mcg (0.25 mg) target at 5 mg/mL requires 0.05 mL. |
| Syringe units | $\text{volume} \times 100$ | A U-100 insulin syringe divides 1 mL into 100 marks. 0.05 mL is 5 units. |
The water volume does not change how much peptide is in the vial — only how far that peptide is spread across the barrel. That is the lever worth using: adding more diluent makes a small amount easier to measure accurately, without altering the amount itself.
Choosing a diluent volume
Measurement error grows as the draw gets smaller. A target landing at 2 units on a U-100 syringe sits between two marks with no margin; the same target in twice the water lands at 4 units and is meaningfully easier to hit.
The calculator’s cleaner measurements suggestions solve this in reverse: it searches diluent volumes between 0.5 and 5 mL and surfaces the ones where your target falls on a whole unit mark.
Working limits:
Keep draws at or above roughly 3 units.
Stay within the barrel’s capacity.
Confirm the vial physically holds the volume before adding it (most 10 mL vials tolerate 3 mL comfortably; smaller vials do not).
Storage
Lyophilized, long term: −20 °C, protected from light and moisture.
Lyophilized, short term: 2–8 °C is acceptable for weeks.
Reconstituted: 2–8 °C, typically used within 28–60 days depending on sequence.
Technique: Run the diluent down the vial wall rather than onto the powder cake, and swirl — never shake. Mechanical agitation denatures peptides.
Freeze-thaw: Aliquot before freezing. Repeated cycling is a common and avoidable cause of degradation.
Planning a protocol
The second tab builds a schedule from a start date, a frequency, and a duration, then projects it against your vial:
Calculates how many administrations each vial provides.
Marks the days a fresh vial is needed.
Totals the mass the protocol consumes.
Exports the whole thing as an
.icsfile that imports into Google Calendar, Apple Calendar, or Outlook.
Your inputs are stored in your own browser only — nothing is transmitted or saved to our servers.