Retatrutide Reconstitution Calculator

What is Retatrutide?

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.

Common vial sizes

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.

• 5 mg vial
• 10 mg vial
• 20 mg vial

Reconstitution examples

Worked examples showing exactly what a given vial, bacteriostatic water volume, and target dose produce in syringe units. All math is from the same calculator above.

• 10 mg vial + 2 mL bacteriostatic water → 5000 mcg/mL concentration.
  A 2000 mcg dose = 40 units on a u-100 insulin, 1 ml (100 units) (0.4 mL).
• 10 mg vial + 2 mL bacteriostatic water → 5000 mcg/mL concentration.
  A 4000 mcg dose = 80 units on a u-100 insulin, 1 ml (100 units) (0.8 mL).
• 20 mg vial + 3 mL bacteriostatic water → 6666.67 mcg/mL concentration.
  A 4000 mcg dose = 60 units on a u-100 insulin, 1 ml (100 units) (0.6 mL).
• 5 mg vial + 2 mL bacteriostatic water → 2500 mcg/mL concentration.
  A 1500 mcg dose = 60 units on a u-100 insulin, 1 ml (100 units) (0.6 mL).

Storage & shelf life

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.

Reported half-life

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.