Peptide Calculator

Dosage & draw volume tool

Enter the vial size, the water you added and your target dose. The exact unit mark comes back drawn on a real syringe — every field updates the result as you type.

Reconstitution

The total peptide printed on the vial label (e.g. 5 mg, 10 mg)
mg
Sterile water with 0.9% benzyl alcohol, so a mixed vial stays usable for weeks
mL

Your Dose

The amount for a single injection from your protocol. 1 mg = 1000 mcg
All three are U-100 insulin syringes (100 units = 1 mL) — the same dose is the same unit number on each.

Your Draw

0 units
Insulin-syringe units on the U-100 scale: 100 units = 1 mL, so 1 unit = 0.01 mL
UNITS · U-100 SCALE
Volume0 mL
Doses per vial

How to Use the Calculator

1Enter the peptide in your vial. In the Reconstitution card, type the total amount printed on the vial label — e.g. 5 mg or 10 mg.
2Enter the bacteriostatic water. Type how many milliliters you plan to add.
3Enter your desired dose. In the Your Dose card, enter the dose from your protocol and choose mcg or mg.
4Choose your syringe size. Select the 30, 50, or 100-unit insulin syringe you're using.
5Read your draw. The results panel shows the volume in mL, the exact units to draw, and how many doses the vial holds.

Frequently Asked Questions

How much bacteriostatic water should I add to a peptide vial?

There's no single correct amount — the water sets the concentration, not the dose. More water gives a larger, easier-to-measure draw; less gives a smaller, more concentrated one. Common choices are 1, 2, or 3 mL — adjust until your draw lands on a convenient syringe mark.

How do I calculate a peptide dose in units?

Divide your dose by the solution's concentration to get the draw in mL, then multiply by 100 for units on a U-100 syringe. For example, 250 mcg from a 2.5 mg/mL solution is 0.1 mL, or 10 units.

What syringe size is best for peptides?

Match the barrel to your draw. A 30-unit (0.3 mL) syringe has the finest marks and suits small doses, 50-unit fits mid-range draws, and 100-unit fits the largest. All three share the same U-100 scale — only the precision differs.

How long does a reconstituted peptide vial last?

Once reconstituted, a peptide solution is less stable than the dry powder — keep it refrigerated and away from light. Reconstituted peptides are generally used within a few weeks, while unmixed powder stays stable much longer in cold storage.

Can I use sterile water instead of bacteriostatic water?

Sterile water has no preservative, so it's best for single use only. Bacteriostatic water contains 0.9% benzyl alcohol, which helps protect a multi-dose vial over its life. The math is the same either way.

How do I convert mcg to mL?

You can't convert mcg to mL without knowing the concentration — mcg measures mass, mL measures volume. Once reconstituted, divide the dose in mcg by the concentration in mcg/mL to get the volume drawn.

Next Steps

For informational and research purposes only. This tool performs unit conversion only and is not medical advice.
Always verify calculations independently and consult a licensed healthcare professional before administering any substance.