Peptide Reconstitution Calculator
Free lab tool
Peptide Reconstitution Calculator
Work out the concentration of a reconstituted vial and how many insulin-syringe units correspond to a given amount. Enter the peptide mass printed on the vial and the volume of bacteriostatic water you add. Everything else is calculated for you.
Results
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Concentration after reconstitution
| Units | Volume | Peptide |
|---|
How the math works
- Concentration = peptide mass ÷ diluent volume. A 5 mg vial reconstituted with 2 mL gives 2.5 mg/mL, which is 2,500 mcg/mL.
- Per unit: a U-100 syringe has 100 units per mL, so each unit holds 0.01 mL. At 2,500 mcg/mL, one unit holds 25 mcg.
- Units for an amount = amount in mcg ÷ mcg per unit. 250 mcg at 25 mcg/unit is 10 units, which is 0.1 mL.
Adding more diluent lowers the concentration and makes small amounts easier to measure. Adding less does the opposite. The total peptide in the vial never changes, only how spread out it is.
Reconstituting a lyophilized vial
- Use bacteriostatic water (0.9% benzyl alcohol) for multi-use vials. Plain sterile water has no preservative.
- Let the diluent run down the inside wall of the vial rather than spraying it onto the powder, then swirl gently. Do not shake; peptides are fragile in solution.
- Keep reconstituted vials refrigerated and note the date. Freeze-thaw cycles degrade peptides, so aliquot into single-use portions if you need to freeze.
- Match the lot code on your vial to its published report in the COA Library before it enters a protocol.
Research peptides with published lot reports
Every FRO Peptides lot ships with a certificate of analysis you can open before you order: HPLC purity and identity from an independent lab, tied to the lot code on the label.
Questions
What is the difference between mg, mcg and units?
Milligrams (mg) and micrograms (mcg) are mass; 1 mg = 1,000 mcg. Units are a volume marking on insulin syringes: on a U-100 syringe, 100 units = 1 mL, so 1 unit = 0.01 mL. How much peptide is in one unit depends entirely on the concentration you made.
How much bacteriostatic water should I add?
There is no single right number. More diluent gives a lower concentration and larger, easier-to-read volumes; less gives a higher concentration. Common lab practice is 1 to 3 mL for a 5 to 10 mg vial. Enter any volume above and the calculator shows the resulting concentration.
Does this tool recommend an amount?
No. The optional “amount to draw” field only converts a number you already have into syringe units. FRO Peptides supplies compounds for laboratory research only and does not provide protocols or dosing guidance.
Can I bookmark my numbers?
Yes. The values you enter are added to the page address, so copying the link keeps your inputs.
For laboratory research use only. Not for human or veterinary use. This calculator performs arithmetic on the values you enter; it is not medical, clinical or dosing advice.