Peptide reconstitution calculator
Enter the vial's milligrams, the bacteriostatic water to add and the target dose per draw. The tool computes concentration, volume per dose and the units in an insulin U-100 syringe.
Calculation tool for laboratory planning (RUO). An insulin U-100 syringe has 100 units = 1 ml. Laboratory reference, not medical advice.
Three steps to prepare the vial
Calculate the volume
Decide how many ml of bacteriostatic water to add based on the concentration you want. Use the calculator above as a reference.
Add the water slowly
Let the bacteriostatic water run down the inner wall of the vial onto the lyophilized powder, without injecting it directly onto it.
Let it dissolve, don't shake
Gently swirl the vial until fully dissolved. Avoid shaking vigorously. Store refrigerated (2–8 °C) and protected from light.
Start from a vial in the catalog
Each button loads that presentation's real milligrams and a common water volume. You can adjust them afterwards.
Concentration of our vials
What concentration you get depending on the water you add, for every presentation in the catalog.
| Vial | 0.5 ml | 1 ml | 2 ml | 3 ml |
|---|---|---|---|---|
| Retatrutide · 5 mg | 10 mg/ml | 5 mg/ml | 2.5 mg/ml | 1.67 mg/ml |
| Retatrutide · 15 mg | 30 mg/ml | 15 mg/ml | 7.5 mg/ml | 5 mg/ml |
| Retatrutide · 30 mg | 60 mg/ml | 30 mg/ml | 15 mg/ml | 10 mg/ml |
| Tirzepatide · 20 mg | 40 mg/ml | 20 mg/ml | 10 mg/ml | 6.67 mg/ml |
| Tesamorelin · 10 mg | 20 mg/ml | 10 mg/ml | 5 mg/ml | 3.33 mg/ml |
| MOTS-c · 40 mg | 80 mg/ml | 40 mg/ml | 20 mg/ml | 13.33 mg/ml |
| BPC-157 + TB-500 · 10 mg | 20 mg/ml | 10 mg/ml | 5 mg/ml | 3.33 mg/ml |
| Ipamorelin + CJC-1295 · 10 mg | 20 mg/ml | 10 mg/ml | 5 mg/ml | 3.33 mg/ml |
| GHK-Cu · 50 mg | 100 mg/ml | 50 mg/ml | 25 mg/ml | 16.67 mg/ml |
| NAD+ · 500 mg | 1,000 mg/ml | 500 mg/ml | 250 mg/ml | 166.67 mg/ml |
| SEMAX · 10 mg | 20 mg/ml | 10 mg/ml | 5 mg/ml | 3.33 mg/ml |
| PT-141 · 10 mg | 20 mg/ml | 10 mg/ml | 5 mg/ml | 3.33 mg/ml |
U-100 syringe equivalence
How many units to draw depending on the concentration you prepared and the mass you want.
| Concentration | 0.1 mg | 0.25 mg | 0.5 mg | 1 mg | 2 mg |
|---|---|---|---|---|---|
| 1 mg/ml | 10 U | 25 U | 50 U | 100 U | 200 U |
| 2 mg/ml | 5 U | 12.5 U | 25 U | 50 U | 100 U |
| 2.5 mg/ml | 4 U | 10 U | 20 U | 40 U | 80 U |
| 5 mg/ml | 2 U | 5 U | 10 U | 20 U | 40 U |
| 10 mg/ml | 1 U | 2.5 U | 5 U | 10 U | 20 U |
| 20 mg/ml | 0.5 U | 1.3 U | 2.5 U | 5 U | 10 U |
Milligrams and micrograms
There is a factor of a thousand between a milligram and a microgram. It is the most common mistake when reconstituting, and the most expensive: getting the unit wrong does not shift the result slightly, it multiplies or divides it by a thousand.
Vials are labelled in milligrams and much of the research literature speaks in micrograms. A 10 mg vial holds 10,000 mcg. If a protocol says 250 mcg, that is 0.25 mg — one fortieth of the vial, not a quarter. The calculator asks for the dose in milligrams and shows the microgram equivalent underneath, so you never have to do that conversion in your head.
Reading an insulin syringe
A U-100 syringe has 100 units per millilitre, so each unit is 0.01 ml. To convert: divide the mass you want by the concentration in mg/ml and multiply by 100.
What changes between syringes is barrel capacity, and with it precision. 40 units fit comfortably in a 1 ml syringe and do not fit at all in a 0.3 ml one — that is why the selector above matters. The tool warns you when the volume does not fit the barrel you picked.
Frequently asked questions
How many units is 0.5 mg?
It depends on the concentration you prepared, not on the peptide. At 2.5 mg/ml it is 20 units; at 5 mg/ml, 10; at 10 mg/ml, 5. The formula: mass in mg ÷ concentration in mg/ml × 100.
Does it work for non U-100 syringes?
The calculator assumes U-100, the standard for human insulin syringes. A veterinary U-40 syringe holds 40 units per millilitre instead of 100, so the units are not equivalent. Check what is printed on the barrel.