Retatrutide Calculator
Dosage and reconstitution math for Retatrutide. A triple agonist of the GLP-1, GIP, and glucagon receptors, investigated in clinical trials as a multi-receptor incretin analog.
Reconstitution calculator
Pre-filled with common defaults for Retatrutide. Adjust any field to match your own vial.
Show the math
Enter values above to see the step-by-step math.
Free Illustrated Reconstitution Guide (PDF)
8-step visual walkthrough with photos and tips — from gathering supplies to drawing your dose. Educational only — not medical advice.
Retatrutide dosage calculator
The Retatrutide dosage calculator above converts a target dose into exact syringe units based on your vial size and how much bacteriostatic water you used to reconstitute it. Retatrutide is commonly sold in 5 mg, 10 mg, 20 mg vials. The calculator supports both U-100 and U-40 insulin syringes and flags draws that are too large for the syringe barrel or too small to measure accurately. A triple agonist of the GLP-1, GIP, and glucagon receptors, investigated in clinical trials as a multi-receptor incretin analog. Enter your target dose in the calculator above to see the exact number of units to draw.
Retatrutide dosage chart
| Sample dose | Concentration | Volume to draw | Units on U-100 |
|---|---|---|---|
| 0.25 mg | 5 mg/mL | 0.05 mL | 5 |
| 0.5 mg | 5 mg/mL | 0.1 mL | 10 |
| 1 mg | 5 mg/mL | 0.2 mL | 20 |
| 2 mg | 5 mg/mL | 0.4 mL | 40 |
| 4 mg | 5 mg/mL | 0.8 mL | 80 |
Retatrutide and GLP-1 peptides
Retatrutide is a GLP-1 / GIP / glucagon triple agonist. A triple agonist of the GLP-1, GIP, and glucagon receptors, investigated in clinical trials as a multi-receptor incretin analog. Other peptides in the GLP-1 class include Semaglutide , and Tirzepatide .
How to reconstitute Retatrutide
Reconstituting Retatrutide is the same unit-conversion process used for any lyophilized peptide:
- Draw your chosen volume of bacteriostatic water into a syringe.
- Inject the bacteriostatic water slowly down the side of the Retatrutide vial — do not shoot it directly onto the powder.
- Swirl gently until the powder fully dissolves. Do not shake.
- Store the reconstituted vial refrigerated.
- To dose, calculate your draw volume: divide your target dose by the concentration (vial mg ÷ water mL = mg/mL). The calculator above does this automatically.
For Retatrutide specifically, 5 mg, 10 mg, 20 mg vials are common. A typical reconstitution adds 2 mL of bacteriostatic water, producing a concentration of 5 mg/mL for the 10 mg vial size.
Retatrutide half-life and storage
Published Phase I/II pharmacokinetic data report a terminal half-life of approximately 6 days, consistent with the albumin-binding design shared by other long-acting incretin analogs.
Lyophilized retatrutide is typically stored refrigerated at 2–8 °C with protection from light. Reconstituted solutions are generally reported to be stable for several weeks under refrigeration, though published stability data for this newer molecule is more limited than for semaglutide or tirzepatide.
Common Retatrutide dosing mistakes
- Confusing mg and mcg. 1 mg = 1,000 mcg. Always convert to the same unit before computing the draw.
- Using a U-40 syringe with U-100 math. Same printed mark, 2.5× the physical volume. Always check the syringe label.
- Not labeling the vial. Write the reconstitution date and concentration on the vial the moment you mix it.
- Under-diluting. If your draw is less than about 1 unit, the volume is too small to read accurately — add more bacteriostatic water next time.