Peptide Reconstitution Calculator
Work out the concentration of a reconstituted vial and convert any target amount into millilitres and a U-100 syringe reading. Works with every vial size in our catalogue and any custom value.
This tool does the arithmetic only. It does not suggest amounts. For research and laboratory use.
How the calculation works
Three steps turn a vial size and a water volume into a reading you can measure accurately.
Concentration
Divide the peptide in the vial by the water you added.
Volume to measure
Divide the target amount by the concentration.
Syringe reading
A U-100 syringe holds 100 units per millilitre, whatever its physical size.
Worked example
At 5 mg/ml, a 2 mg measure is 2 ÷ 5 = 0.4 ml, which reads as 40 units on a U-100 syringe.
Conversion at 5 mg/ml
| Syringe mark | Volume | Amount |
|---|---|---|
| 10 units | 0.10 ml | 0.5 mg |
| 20 units | 0.20 ml | 1 mg |
| 40 units | 0.40 ml | 2 mg |
| 100 units | 1.00 ml | 5 mg |
Choosing a syringe size
All three sizes use the same U-100 scale. Smaller barrels spread the markings further apart, which makes small volumes easier to read.
- 0.3 ml (30 units): clearest markings for volumes up to 0.3 ml.
- 0.5 ml (50 units): a good middle ground for volumes up to 0.5 ml.
- 1.0 ml (100 units): needed once the volume goes past 0.5 ml.
More water or less water?
More water makes a weaker solution, so the same amount takes up more volume. Less water makes a stronger solution and a smaller volume. The total amount in the vial does not change. Pick a volume that gives a reading that is easy to measure.
Reconstitution steps
General lab handling for lyophilised (freeze-dried) peptide vials.
Prepare
Work on a clean, flat surface. Wipe the rubber stopper of the vial and the water vial with an alcohol swab and let them dry.
Add water slowly
Draw the planned volume of bacteriostatic water and let it run slowly down the inside wall of the vial, not straight onto the powder.
Swirl, do not shake
Gently swirl or roll the vial until the solution is clear. Shaking can damage the peptide structure.
What you need
- Peptide vial: lyophilised powder, sealed.
- Bacteriostatic water: sterile diluent. Available in our shop.
- U-100 syringe: sold separately.
- Alcohol swabs.
Storage
| State | General guidance |
|---|---|
| Sealed powder | Cool, dry and dark. Freezer (−20°C) for long-term storage. Avoid repeated freeze and thaw. |
| After mixing | Refrigerate at 2–8°C. Do not freeze. |
| Shelf life | Varies by compound. Check the product page. |
Questions
What is a U-100 syringe?
A syringe marked in units where 100 units equal 1 ml. The 0.3 ml, 0.5 ml and 1.0 ml sizes all use this same scale, so 10 units is always 0.1 ml.
Can I use this for any peptide?
Yes. Pick a product to fill in its vial size, or type any amount in mg. The maths is the same for every compound.
What if the result is more than my syringe holds?
The calculator warns you. Choose a larger syringe, or use less water so the solution is more concentrated.
How do I convert mg to mcg?
1 mg equals 1,000 mcg. Use the mg or mcg switch next to the amount field and the calculator converts it for you.