Retatrutide Reconstitution Calculator: Dose & Syringe Units

Worked examples

10 mg vial, 2 mL water, 2 mg dose

Concentration = 10 ÷ 2 = 5 mg/mL. Volume = 2 ÷ 5 = 0.4 mL = 40 units on a U-100 syringe. About 5 doses per vial.

10 mg vial, 1 mL water, 1 mg dose

Concentration = 10 ÷ 1 = 10 mg/mL. Volume = 1 ÷ 10 = 0.1 mL = 10 units. About 10 doses per vial.

20 mg vial, 2 mL water, 4 mg dose

Concentration = 20 ÷ 2 = 10 mg/mL. Volume = 4 ÷ 10 = 0.4 mL = 40 units. About 5 doses per vial.

Keeping units under the syringe limit

A 2 mg dose at 5 mg/mL is 40 units, which fits a 0.5 mL (50-unit) syringe but not a 0.3 mL (30-unit) one. The calculator warns you when a dose overflows the syringe you picked.

Reconstituting retatrutide, step by step

Retatrutide is an investigational triple receptor agonist (GIP, GLP-1, and glucagon) still in clinical trials. Research-grade vials arrive as a lyophilized powder that must be reconstituted with bacteriostatic water before a dose can be measured. The reconstitution math is identical to any peptide; retatrutide simply tends toward milligram doses, so keep an eye on how many units they produce.

The three steps

Concentration = vial (mg) ÷ water (mL). A 10 mg vial in 2 mL of bacteriostatic water is 5 mg/mL.
Volume = dose (mg) ÷ concentration (mg/mL). A 2 mg dose at 5 mg/mL is 2 ÷ 5 = 0.4 mL.
Units = volume (mL) × 100. 0.4 mL is 40 units on a U-100 insulin syringe.

Watch the syringe capacity

Because retatrutide doses can be relatively large, it is easy to produce a volume that will not fit a small syringe. A 2 mg dose at 5 mg/mL needs 40 units, which fits a 0.5 mL (50-unit) barrel but overflows a 0.3 mL (30-unit) one. If that happens you can dilute with more water, draw the dose in two parts, or switch to a larger syringe. The calculator warns you the moment a dose exceeds the capacity you selected.

Doses per vial

Divide the vial size by your dose to see how many injections it holds: a 10 mg vial at 2 mg per dose gives 5 doses. The water volume does not change this number.

Important safety note

Retatrutide is not an approved medicine. It is an investigational compound, and research-grade vials are sold strictly for laboratory research, not human use. This calculator performs reconstitution arithmetic only; it does not recommend a dose, a schedule, or any use, and it cannot judge what is safe. Treat every result as an educational estimate, not medical advice. Verify your vial label, consult a licensed medical professional, and follow all applicable laws.

Frequently asked questions

How do I reconstitute retatrutide?

Add bacteriostatic water to the freeze-dried powder, then divide the milligrams in the vial by the millilitres of water for the concentration. Divide your target dose by that concentration to get the volume, and multiply by 100 for units on a U-100 insulin syringe. The calculator handles all three steps.

How much water should I add to retatrutide?

The water volume is your choice and only sets the concentration, not the dose. Because retatrutide doses are measured in milligrams and can be larger than other GLP-1 peptides, watch that the resulting units fit inside your syringe. Adding more water lowers the units per dose; adding less raises them.

Why do my retatrutide units seem high?

Higher milligram doses at a low concentration produce a large volume and therefore a high unit count. If a dose overflows your syringe, either add more water to dilute it, split it across two draws, or use a larger-capacity syringe. The calculator flags an overflow automatically.

Is this retatrutide calculator medical advice?

No. Retatrutide is an investigational compound that is not approved for human use, and research-grade vials are sold for laboratory research only. This tool performs reconstitution math and nothing more. It does not recommend a dose or judge safety. Consult a licensed medical professional and follow all applicable laws.