Retatrutide Dosing Calculator
How the math works
Every result comes from three numbers: the milligrams of peptide in the vial, the volume of bacteriostatic water added and the dose amount to convert. A U-100 insulin syringe is marked at 100 units per mL. Changing the water volume changes how many units a dose occupies, not the amount of peptide in the dose.
Concentration
vial (mg) ÷ water (mL)
Draw volume
dose (mg) ÷ concentration (mg/mL)
Syringe units
draw volume (mL) × 100
Example
A 6 mg vial of Retatrutide reconstituted with 2.5 mL of bacteriostatic water yields 2.4 mg/mL. A 600 mcg dose measures 25 units on a U-100 syringe.
About Retatrutide
GLP-3 R (LY3437943) is an investigational peptide developed by Eli Lilly that acts as a triple hormone receptor agonist, targeting GLP-1, GIP, and glucagon receptors. This next-generation compound is being studied for its powerful effects on weight loss, insulin sensitivity, and metabolic health. The unique triple-receptor mechanism may allow Retatrutide to outperform single or dual agonists like GLP-1 or GLP-2.
Frequently asked questions
How do I calculate a Retatrutide dose in units?
Enter the vial size, the amount of bacteriostatic water used and the dose amount. The calculator returns the number of units to draw on a U-100 insulin syringe for Retatrutide, along with an estimate of how many doses the vial holds.
What is peptide reconstitution?
Reconstitution is mixing a measured amount of bacteriostatic water into a freeze-dried peptide vial to create a solution you can measure in syringe units. The amount of peptide stays the same; the water only changes how much peptide each syringe unit contains.
How do I read units on an insulin syringe?
A standard U-100 insulin syringe is marked in units where 100 units equal 1 mL, so each unit is 0.01 mL. The calculator converts the volume of your dose into that unit scale.
Why is my dose in milligrams but the syringe reads units?
Milligrams measure the amount of peptide; units measure the volume you draw. The conversion depends on concentration (the vial's milligrams divided by the milliliters of water added), which is what this calculator computes.
What if a dose needs more than 100 units?
A 1 mL U-100 syringe holds a maximum of 100 units. If a dose exceeds that, reconstitute with less water (a higher concentration) so the same dose occupies fewer units, or split it into more than one draw.
Is this medical advice?
No. This tool performs reconstitution math for research and educational reference only. It is not medical advice or a dosing recommendation. Compounds referenced on this site are for laboratory research use only.
Disclaimer
This calculator is provided for research and educational reference only. It performs reconstitution math from the vial contents and diluent volume you enter and is not medical advice, a dosing recommendation, or a substitute for a qualified professional. Compounds referenced on this site are for laboratory research use only and are not intended for human or animal consumption.