Free tool · no signup
Retatrutide reconstitution calculator.
Reconstituting a lyophilized retatrutide vial? Enter the mg in the vial, the bacteriostatic water you add, and your target dose. You get the exact concentration, the volume to draw in mL, and the units on a U-100 syringe. No rounding, no account, and the full math is shown every time.
Units shown for a U-100 insulin syringe (1 mL = 100 units). No rounding · the full math is above.
How the math works
Three steps, no hand-waving.
Reconstitution is simple arithmetic. The only thing that matters is that it is exact, and that you can see every step.
Vial mg ÷ BAC water mL = mg/mL. A 10 mg vial in 2 mL of water is 5.0000 mg/mL.
Target dose ÷ concentration = mL to draw. 2 mg ÷ 5.0000 mg/mL = 0.4000 mL.
Draw mL × 100 = units on a U-100 insulin syringe. 0.4000 mL = 40 units.
Background
What retatrutide reconstitution is
Retatrutide is an investigational triple-agonist supplied as a lyophilized powder that has to be reconstituted with bacteriostatic water before any dose can be drawn. Concentration is the mg in the vial divided by the mL of water you add. Because retatrutide is titrated in small milligram steps over months, the draw volume changes at every step. This calculator runs that arithmetic exactly so each draw is precise, with no hidden rounding.
- Reconstitution built into the dose logger, not a separate tool
- 28-day BAC water expiry countdown per vial
- Doses remaining and refill warnings, all derived
- Local-first · no account, data stays on your device
FAQ
Retatrutide reconstitution questions, answered.
How do you calculate a retatrutide dose?
Divide the mg of retatrutide in the vial by the mL of bacteriostatic water you add to get the concentration in mg/mL. Then divide your target dose (in mg) by that concentration for the draw volume in mL. Multiply by 100 for units on a U-100 insulin syringe.
How much BAC water for a 10mg retatrutide vial?
There is no single correct amount. 2 mL gives 5 mg/mL; more water lowers the concentration and gives a larger, easier-to-measure draw. Enter the amount you plan to add and the calculator returns your exact numbers for any target dose.
How do I convert retatrutide mcg to mg?
1 mg equals 1000 mcg. Enter your dose in whichever unit your protocol uses and the calculator converts before solving, so a 2 mg dose and a 2000 mcg dose return the same draw volume.
How is retatrutide different from semaglutide and tirzepatide?
Retatrutide is a triple agonist, acting on the GLP-1, GIP, and glucagon receptors, while semaglutide targets GLP-1 and tirzepatide targets GLP-1 and GIP. The reconstitution arithmetic is identical for all three; only the molecule and its regulatory status differ, and retatrutide remains investigational.
Why does the exact retatrutide draw matter?
At these concentrations a small volume error is a large dose error, and because retatrutide is investigational there is no approved label to fall back on. Showing the draw volume and units to four decimal places removes the rounding guesswork. Confirm anything you do with a qualified provider.
Is retatrutide FDA approved?
No. As of 2026 retatrutide is investigational and not approved by the FDA for any use. This tool is arithmetic only and is not a recommendation to use it. See the retatrutide explainer in our learn hub for the regulatory picture.
Is this medical advice?
No. This calculator performs arithmetic on the values you enter. It does not recommend a dose, schedule, or source. Confirm anything you do with a qualified provider.
- 1Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. doi:10.1056/NEJMoa2301972
- 2Retatrutide compound summary. PubChem, US National Library of Medicine
This tool performs reconstitution arithmetic only. It is not medical advice and does not recommend any compound, dose, schedule, or source. Always follow guidance from a qualified provider. See our medical disclaimer.