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Peptide Calculator
Made Simple

Enter a vial size, your BAC water, and a dose. Get the exact units to draw. Free, and for research purposes only.

Peptide Calculator Peptide Tracker

Nexa Labs is intended for research purposes only. Nothing on this site constitutes medical advice.

Optional. Sets the vial and dose chips.

mg

Peptide in the vial

mL

Water added to the vial

mcg

Per injection

Syringe
Draw to
10.0units
Volume
0.100 mL
Syringe
1.0 mL U-100
Dose
250 mcg
20406080100
Concentration
2.50 mg/mL
Doses in vial
20
Lasts
~2.9 weeks at
Add to tracker

How Do I Use a Peptide Calculator?

Three inputs, one number. The exact units to draw, in seconds.

01

Enter your vial size

Type the total peptide in mg. Select a compound from the list to prefill common vial sizes, or enter any custom amount.

02

Add your BAC water volume

Enter how many mL of bacteriostatic water you reconstituted with, then the dose you actually want to take.

03

Read your exact draw amount

The units to draw appear immediately, with the fill line marked on a syringe diagram. Warnings flag a draw that will not fit, exceeds the vial, or is too small to measure.

Peptide Tracker

Turn a dose into a schedule

The calculator tells you what to draw. The tracker tells you when. Pick a protocol, set a start date, and get every administration laid out with the injection site already rotated for you.

Open the tracker

  • Protocol presets

    Daily, every other day, 3x a week, 5-on-2-off, or weekly, from any start date.

  • Rotation

    Each administration gets the next of your own labels, so nothing repeats back to back.

  • Calendar export

    Download an .ics and every date lands in your own calendar app.

  • Printable sheet

    A one-page protocol sheet to keep beside the vial.

What is peptide reconstitution?

Lyophilized (freeze-dried) peptides must be reconstituted with bacteriostatic water before use. The reconstitution process determines the final concentration, which is essential for calculating accurate doses.

The formula

Concentration (mcg/mL) = (Vial size in mg x 1000) / BAC water added (mL)

For example: a 5mg vial reconstituted with 2mL of BAC water yields 2,500 mcg/mL. To draw a 250 mcg dose, you would need 0.1 mL (10 units on a U-100 syringe).

U-100 vs U-40 syringes

U-100 syringes hold 100 units per mL. U-40 syringes hold 40 units per mL. The same volume reads as a different unit number depending on the syringe type — this is one of the most common sources of dosing errors.

Read the full reconstitution guide Back to the calculator

Common questions

Divide your vial size in mcg (mg x 1000) by the amount of bacteriostatic water added in mL. For example, a 5mg vial with 2mL BAC water gives 2500 mcg/mL.

U-100 syringes have 100 units per mL; U-40 syringes have 40 units per mL. The same volume of liquid equals a different unit marking depending on the syringe type, which is a common source of dosing errors.

All calculations use standard pharmaceutical math with no rounding until the final display. Results are as accurate as the values you enter. These tools are for research purposes only.

Yes. The calculator and the tracker are free, with no account and no login. Your protocols stay in your browser. The site is supported by affiliate links to supplies, and those never change what the calculator says.

The math runs on your device and we never see what you type. The numbers are written into the page address so you can bookmark or share a result, and if you accept analytics cookies, that address is counted as a visit. Your last inputs and syringe choice are remembered on this device only.