Calculator
Peptide Reconstitution Calculator
This tool does one thing: arithmetic. Enter the peptide amount printed on your vial, how much bacteriostatic water you mixed into it, and the dose you have already decided on — in milligrams. It converts that into insulin-syringe units at your stated concentration and shows every step, so you can check the math yourself. It has no dose of its own to offer, and it will never suggest one.
This tool does not recommend a dose
Enter your own numbers
Calculator
Total peptide mass printed on the vial label.
How much diluent you mixed into the vial.
Nothing here is suggested — this is the dose you have already decided on.
Enter all three numbers above — vial strength, water added, and your target dose, each greater than zero — to see the result.
Read this too
What this calculator does not tell you
It does not know your real concentration
It does not know whether a quantity is appropriate
It does not verify sterility, purity, or legality
The arithmetic
How the math works
Three numbers go in: the peptide amount printed on the vial (mg), the bacteriostatic water you mixed into it (mL), and the dose you have already decided on (mg).
Concentration = vial strength (mg) ÷ water added (mL), in milligrams per milliliter.
Syringe units = (target dose (mg) ÷ concentration (mg/mL)) × 100 — because a standard insulin syringe is marked so that 100 units equal 1 mL. That assumption is fixed, shown on the page, and never hidden in the arithmetic.
For the longer version, including where a straightforward division goes wrong, read the full worked example, checked against the label.
Glossary
Key terms
- Reconstitution
- Adding a liquid — usually bacteriostatic water — to a freeze-dried (lyophilized) peptide powder to turn it into an injectable solution.
- Concentration (mg/mL)
- How much peptide sits in each milliliter of the mixed solution — the exchange rate between a mass and a volume.
- Bacteriostatic water
- Sterile water with a small amount of benzyl alcohol added as a preservative, which lets a multi-dose vial be entered repeatedly rather than used once and discarded.
- Syringe units (U-100)
- The markings on a standard U-100 insulin syringe, where 100 units equal 1 milliliter. A different syringe, such as a U-40, uses a different scale entirely.
- Draw volume
- The volume of mixed solution — in milliliters — that contains your target dose. This is what the syringe-unit figure is converted from.
- Vial strength
- The total mass of peptide printed on the vial's label, in milligrams — before any water is added.
Before you calculate
Approval status of peptides commonly reconstituted this way
The arithmetic above is identical no matter which peptide is in the vial. What you are legally able to obtain is not — it varies by compound, and it is worth checking before you calculate anything.
- TesamorelinFDA-approved
- CJC-1295 and IpamorelinCompounding restricted
- RetatrutideResearch use only
- AOD-9604Research use only
- MOTS-cResearch use only
Questions
Frequently asked questions
Does this calculator tell me how much of a peptide to take?
No. It never recommends, suggests, or defaults to a dose. You supply the target dose you have already decided on, in milligrams, and it converts that number into syringe units at the concentration you mixed. If you have not already decided on a dose, this tool has nothing to compute for you.
What does '100 units equal 1 mL' mean?
It is the printed scale on a standard U-100 insulin syringe, the kind most commonly used to draw reconstituted peptides. The barrel is marked in units rather than milliliters, and 100 of those units hold exactly 1 mL. This calculator's unit output assumes that syringe; a different syringe, such as a U-40, uses a different scale entirely.
The result says my target dose exceeds the vial. What does that mean?
It means the milligram figure you entered as your target dose is larger than the total milligrams the vial label says it contains. The arithmetic still runs and shows the number, but that number is asking for more peptide than is physically in the vial — worth rechecking before you draw anything.
Medical disclaimer: This content is for general educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a licensed healthcare professional before starting, stopping, or changing any treatment.