Retatrutide (LY3437943) is an investigational drug from Eli Lilly that acts on GIP, GLP-1 and glucagon receptors. It is not FDA approved as of October 2026.
Also known as: LY3437943.
There is no approved retatrutide product. Powder vials are usually labeled 5 mg, 10 mg or 20 mg.
Here is the math for a 10 mg vial mixed with 2 mL of bacteriostatic water, drawing 2 mg with a U-100 insulin syringe (1 mL = 100 units).
10 mg ÷ 2 mL = 5 mg/mL2 mg ÷ 5 mg/mL = 0.4 mL0.4 mL × 100 = 40 units| Amount | Volume | U-100 syringe |
|---|---|---|
| 1 mg | 0.2 mL | 20 units |
| 2 mg | 0.4 mL | 40 units |
| 4 mg | 0.8 mL | 80 units |
Adding more water doesn't change how much retatrutide is in the vial. It only spreads it over more liquid, so each draw is bigger and easier to read.
| Water added | Concentration | Volume | U-100 syringe |
|---|---|---|---|
| 1 mL | 10 mg/mL | 0.2 mL | 20 units |
| 2 mL | 5 mg/mL | 0.4 mL | 40 units |
| 3 mL | 3.33 mg/mL | 0.6 mL | 60 units |
| 5 mL | 2 mg/mL | 1 mL | 100 units |
For any other vial size or amount, the free peptide reconstitution calculator works backwards from the amount you want and suggests a water volume that lands on a clean syringe mark.
A phase 1b trial (Urva 2022) reported a half-life of about 6 days. We could not confirm a published time to peak, so we leave it out.
Numbers shown are the values Dose Track uses, listed only where they agree with the source above. Half-life varies from person to person and with injection site.