Retatrutide Calculator

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

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 .

Retatrutide is a synthetic peptide that has been studied as a triple agonist at the GLP-1, GIP, and glucagon receptors. The triple-receptor approach is a more recent addition to the incretin-based research landscape and has been investigated in Phase II clinical trials reported in journals including the New England Journal of Medicine. The molecule retains the albumin-binding fatty acid architecture common to long-acting incretin analogs, which accounts for its extended plasma half-life. As of this writing, retatrutide is an investigational compound and has not been approved by the FDA or other major regulators for clinical use. Research-grade material sold by chemical supply companies is labeled for laboratory use only.

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How to reconstitute Retatrutide

Research vendors typically offer retatrutide in 5 mg, 10 mg, and 20 mg lyophilized vials. Because the compound is newer, vial size conventions are still evolving across suppliers.

Reconstituting Retatrutide is the same unit-conversion process used for any lyophilized peptide:

1. Draw your chosen volume of bacteriostatic water into a syringe.
2. Inject the bacteriostatic water slowly down the side of the Retatrutide vial — do not shoot it directly onto the powder.
3. Swirl gently until the powder fully dissolves. Do not shake.
4. Store the reconstituted vial refrigerated.
5. 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

Most Retatrutide draw errors are unit errors, not arithmetic errors: confusing mg with mcg (1 mg = 1,000 mcg), or reading a U-40 syringe with U-100 math — the same printed mark holds 2.5× the volume. Two more worth avoiding: leaving the vial unlabeled, so the concentration and reconstitution date are lost, and under-diluting to the point where the draw is under about one unit and can no longer be read accurately.

Each of these is covered in full in the guides: reconstitution math from first principles, U-100 vs U-40 syringes, storage and shelf life, and how to reconstitute peptides.