Retatrutide Reconstitution & Dose Calculator
Retatrutide is an investigational triple agonist (it acts on the GLP-1, GIP, and glucagon receptors) from Eli Lilly. As of now it is still in clinical trials and is not FDA-approved. This free calculator turns a Retatrutide vial plus reconstitution solution (bacteriostatic water) into insulin syringe units to draw. It is unit-conversion math, not a dosing recommendation. Retatrutide vials are commonly 10 mg, 15 mg, 20 mg, so the tool below starts at 10 mg; change any field to match your own vial.
No single volume of reconstitution solution is correct for a 10 mg Retatrutide vial: the amount added sets the concentration. Concentration equals vial milligrams divided by millilitres added — 10 mg in 1 mL gives 10 mg/mL, in 2 mL 5 mg/mL. Syringe units follow from that concentration.
Reconstitution calculator
Pick your peptide, vial size, and BAC water. Get exact units to draw on a 1 mL insulin syringe.
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Type to search, or pick from the dropdown. Auto-fills the recommended vial size.
- • Standard insulin syringe = 100 units total
- • Small markings = 1 unit each
- • Large markings = 10 units (0.1 mL)
- • 100 units = 1 mL
Always verify reconstitution math against a second source before any dose you actually inject.
How much reconstitution solution a Retatrutide vial needs
There is no single correct amount. The reconstitution solution is usually bacteriostatic water, though the diluent and volume are set by your product’s own instructions, not by a general rule. What you add is what sets the concentration: vial mg divided by mL of liquid. Adding more makes a weaker mix and a bigger, easier-to-read draw on the syringe. To hit a concentration you have in mind, divide the vial mg by it, so a 10 mg vial at 5 mg/mL needs 2 mL. Below are common Retatrutide vial sizes at three common volumes (U-100 insulin syringe, where 1 unit = 0.01 mL). These rows are arithmetic only. They do not tell you which diluent, volume, or concentration is appropriate for the product in your hand.
| Vial | Reconstitution solution | Concentration | Per insulin unit | 50 units (0.50 mL) holds |
|---|---|---|---|---|
| 10 mg | 1 mL | 10 mg/mL | 100 mcg | 5 mg |
| 10 mg | 2 mL | 5 mg/mL | 50 mcg | 2.50 mg |
| 10 mg | 3 mL | 3.33 mg/mL | 33.33 mcg | 1.67 mg |
| 15 mg | 1 mL | 15 mg/mL | 150 mcg | 7.50 mg |
| 15 mg | 2 mL | 7.50 mg/mL | 75 mcg | 3.75 mg |
| 15 mg | 3 mL | 5 mg/mL | 50 mcg | 2.50 mg |
| 20 mg | 1 mL | 20 mg/mL | 200 mcg | 10 mg |
| 20 mg | 2 mL | 10 mg/mL | 100 mcg | 5 mg |
| 20 mg | 3 mL | 6.67 mg/mL | 66.67 mcg | 3.33 mg |
Worked example: a 10 mg Retatrutide vial in 2 mL of bacteriostatic water is 5 mg/mL. One unit on a U-100 pin is 50 mcg, so if your protocol calls for 2.50 mg you would draw to 50 units. That is arithmetic from the numbers you enter, nothing more. Pepdex does not tell you what dose to take.
Retatrutide reconstitution questions
- How do you reconstitute Retatrutide, and what do you mix it with?
- The reconstitution solution is usually bacteriostatic water, but use only the diluent and volume specified in your product's own labeling or dispensing instructions. General technique: add the liquid slowly down the inside wall of the vial, let the powder dissolve on its own without shaking, and keep the mixed vial refrigerated. The amount you add sets the concentration. A 10 mg vial in 2 mL is 5 mg/mL; the same vial in 1 mL is 10 mg/mL. Use the calculator above to run your own numbers.
- How much reconstitution solution do you need for a 10 mg Retatrutide vial?
- As much as it takes to reach the concentration you are aiming for, which is why no single number is the answer. Divide the vial mg by your target concentration to get the mL: a 10 mg vial at 10 mg/mL takes 1 mL, at 5 mg/mL takes 2 mL, and at 3.33 mg/mL takes 3 mL. The table above runs the same math for the common Retatrutide vial sizes (10 mg, 15 mg, 20 mg). Any vial size works in the calculator, including one not listed here. Which concentration is appropriate is set by your product's instructions, not by this page.
- How many insulin units is a dose of Retatrutide?
- It depends entirely on how much water you mixed, because milligrams describe the powder and units describe the volume drawn. With a 10 mg vial reconstituted in 2 mL, one unit on a U-100 pin is 50 mcg, so 50 units draws 2.50 mg. Change the water and that number changes. Enter your numbers above to get yours.
- What vial sizes does Retatrutide come in?
- Commonly 10 mg, 15 mg, 20 mg. The calculator defaults to 10 mg for Retatrutide but you can set any vial size. Always work from the mg printed on the vial you actually have, not a number from a forum.
- Is retatrutide the same as tirzepatide?
- No. Tirzepatide is a dual agonist (GIP and GLP-1). Retatrutide adds a third target, the glucagon receptor, which is why it is called a triple agonist. They are different molecules and ship in different vial sizes, so the reconstitution numbers are not interchangeable. Run your actual vial through the calculator above.
- Is the Retatrutide calculator free?
- Yes. The reconstitution and units math is completely free with no account. A free account also saves your protocol. The AI Coach and Personal Stack are part of membership.
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Educational reference only. Pepdex does not sell peptides, recommend vendors, or tell you what dose to take. Retatrutide reconstitution math here is unit conversion you can verify by hand. Talk to a qualified provider about your own use.