Peptide Reconstitution Calculator

The math

Type three things: the mg in your vial, the mL of liquid added, and your amount in mg or mcg. Pick your syringe, and the tool shows units, mL, mg per mL, and how many full draws the vial holds.

mg per mL

Start with the strength after mixing. Divide the mg in your vial by the mL of liquid to get mg per mL.

That number is the base for everything under it. If you want the same arithmetic written out, see how to reconstitute peptides: the math, step by step.

mL to draw

Use your amount next. Divide the amount from your label or plan by the mg per mL number to get the mL to draw.

The amount field starts empty and stays that way until you type your number. There are no preset amounts.

units on your syringe

Now convert mL into syringe units. On a U-100 syringe, ADA: Overview of Insulin Concentration for School Nurses (opens in a new tab) and MedlinePlus: Giving an insulin injection (opens in a new tab) describe 100 units in 1 mL. The calculator multiplies the mL by 100.

If your amount is in mcg, the tool converts it before doing the rest. For example, 0.5 mg is 500 mcg, which is the same amount.

Example numbers to show the math, not an amount to take.

• 10 mg in the vial, 2 mL of liquid added, 0.5 mg wanted per draw (500 mcg), U-100 syringe.
• Step 1: 10 mg ÷ 2 mL = 5 mg/mL.
• Step 2: 0.5 mg ÷ 5 mg/mL = 0.1 mL.
• Step 3: 0.1 mL × 100 units per mL = 10 units.
• Answer shown by the tool: 10 units · 0.1 mL.
• On paper, 10 mg ÷ 0.5 mg = 20 full draws from this vial (leftover liquid in the syringe and vial is not counted).

Syringe marks for your numbers

The table under this heading helps you match the result to your own barrel. Count the lines on your own barrel, and let the printed numbers tell you the step.

When you read the result, line up the plunger tip with the line. Follow your own syringe's instructions, as shown in FDA: instructions for use on a U-100 insulin vial label (opens in a new tab). If the answer is above your syringe's capacity, use a larger syringe.

Three places numbers get mixed up

One mix-up is total mg versus mg per mL. FDA says label strength can make the per mL number look like the total amount in the container, as described by FDA: strength on compounder and manufacturer labels (opens in a new tab). Check which number is which on your label, while the tool shows each step underneath.

Another mix-up is mL versus units. FDA also points to confusion between milliliters, milligrams, and units when people measure from a vial, per FDA alert on dosing errors with compounded injectables (opens in a new tab). This result shows units and mL together, and why mg and units are not the same walks through the difference.

The last one is syringe type. ADA: Overview of Insulin Concentration for School Nurses (opens in a new tab) says a syringe must match the vial concentration, so use the syringe setting that matches what you have in hand.

Is this a peptide dosage calculator?

Only in the sense that it converts the amount you enter. It never suggests an amount.

All fields start empty. That includes the amount field with the placeholder "amount from your label or plan." Presets exist only for packaging values: mg in the vial and mL of liquid.

The result shows units and mL together, then mg per mL, then how many full draws the vial holds. The syringe drawing under the answer is drawn to scale for the number shown.

Your entries stay in the browser on this device. No account is needed, and there is no usage limit.

If you need help beyond the arithmetic, follow the label and ask your pharmacist or prescriber.

After the math

You can Save as a vial to keep the result as a vial on this device, with no account needed. After that, you can Set a schedule, and if it fits what you're doing, use Remind me or Print / Copy result.

A 1 mL U-100 syringe scale

Example numbers only. Check the numbers printed on your own syringe.