Peptide & GLP-1 Dose Calculator
Precise dosing, zero guesswork.
The lab-grade calculator for peptide reconstitution and GLP-1 therapy. Calculate your dose and visualize exactly how far to draw the plunger.
Dose Calculator
Enter your vial size, bacteriostatic water, and target dose to see the exact units to draw on a to-scale insulin syringe.
Popular dosing guides
What is a peptide dosing calculator?
A peptide dosing calculator converts your vial strength and the bacteriostatic water you add into a mg/mL concentration, then tells you the exact volume — and the units on a U-100 insulin syringe — to draw for your target dose. Keel does this for GLP-1 medications like semaglutide and tirzepatide and for research peptides like BPC-157, then renders the draw on a to-scale syringe.
How to calculate a peptide dose
- 1
Pick your compound
Choose semaglutide, tirzepatide, BPC-157, or any compound from the library. Sensible reconstitution defaults load automatically.
- 2
Enter vial, water, and dose
Type your vial strength in milligrams, the bacteriostatic water you added, and your target dose in mg or mcg.
- 3
Read the syringe
Keel shows the concentration, the volume in mL, and the exact units to draw — rendered on a to-scale insulin syringe with an over-draw warning.
Peptide dosing FAQ
How do I calculate my peptide dose?
Divide the vial strength (mg) by the bacteriostatic water added (mL) to get the concentration in mg/mL. Divide your target dose by that concentration to get the volume in mL, then multiply by 100 for the units on a U-100 insulin syringe. Keel does this automatically and draws it on the syringe.
How much bacteriostatic water should I use to reconstitute a vial?
It depends on the concentration you want and how easy you want the draw to read. Less water makes a more concentrated solution and a smaller draw; more water makes a larger, easier-to-measure draw. Many users add 1-3 mL. The calculator updates the units instantly as you change the water volume.
How do I calculate my semaglutide dose?
Reconstitute the vial, for example 5 mg in 2 mL of bacteriostatic water for 2.5 mg/mL. A 0.25 mg dose is then 0.1 mL, which is 10 units on a U-100 insulin syringe. Use the semaglutide page for a worked example and a built-in calculator.
What is the difference between units and milligrams?
Milligrams (or micrograms) measure the amount of peptide; units measure the volume on an insulin syringe (100 units = 1 mL). The calculator converts your milligram dose into the units you actually draw, which depends entirely on your concentration.
Is Keel free?
Yes. The calculator is free to use. A free account lets you save your protocols to My Doses and share any calculation with a private link.
Is Keel medical advice?
No. Keel is for educational and research purposes only and is not medical advice. Always consult a licensed healthcare professional before starting any protocol.
Related reading
- Reconstitution & mixing
How to Reconstitute a Peptide
To reconstitute a peptide, slowly add bacteriostatic water down the side of the vial, let it dissolve without shaking, then divide the vial strength by the water volume to get a mg/mL concentration. Divide your dose by that concentration to find the volume, and multiply by 100 for units on a U-100 syringe.
- Reconstitution & mixing
Bacteriostatic Water Explained
Bacteriostatic water is sterile water with about 0.9% benzyl alcohol added to inhibit bacterial growth, making it suitable for multi-dose vials. It is the standard diluent for reconstituting lyophilized peptides. The volume you add sets the concentration and how many units you draw, but never changes the milligram dose itself.
- Dosing fundamentals
Reading an Insulin Syringe: Units vs mL
On a standard U-100 insulin syringe, 100 units equal 1 mL, so each unit is 0.01 mL. To convert a dose volume to units, multiply the millilitres by 100. Insulin syringes come in 0.3 mL (30 units), 0.5 mL (50 units), and 1 mL (100 units) sizes; smaller barrels give finer, more accurate marks for small draws.
- Peptides & protocols
Peptide Stacking Basics
A peptide stack is two or more compounds run together as one protocol, such as BPC-157 with TB-500 for recovery. Each compound is reconstituted and dosed separately, with its own concentration and draw. Planning a stack means calculating every compound individually and combining them into one weekly schedule and budget.