Retatrutide reconstitution & dose calculator
Enter your Retatrutide vial size, the BAC water you added and your dose to see the units to draw on a U-100 insulin syringe.
- Strength
- 5 mg/mL
- 1 unit holds
- 50 mcg
Retatrutide reconstitution chart: units to draw by vial size and BAC water
Find the row for the mg on your vial and the water you added. Amounts are the 2 mg steps on our retatrutide page, from 2 mg up to the 12 mg top dose used in trials. Units are on a U-100 insulin syringe, where 100 units is 1 mL.
| Vial | BAC water | Strength | Units to draw for | |||||
|---|---|---|---|---|---|---|---|---|
| 2 mg | 4 mg | 6 mg | 8 mg | 10 mg | 12 mg | |||
| 5 mg | 1 mL | 5 mg/mL | 40 | 80 | more than the vial | more than the vial | more than the vial | more than the vial |
| 2 mL | 2.5 mg/mL | 80 | 160* | more than the vial | more than the vial | more than the vial | more than the vial | |
| 3 mL | 1.67 mg/mL | 120* | 240* | more than the vial | more than the vial | more than the vial | more than the vial | |
| 10 mg | 1 mL | 10 mg/mL | 20 | 40 | 60 | 80 | 100 | more than the vial |
| 2 mL | 5 mg/mL | 40 | 80 | 120* | 160* | 200* | more than the vial | |
| 3 mL | 3.33 mg/mL | 60 | 120* | 180* | 240* | 300* | more than the vial | |
| 15 mg | 1 mL | 15 mg/mL | 13.3 | 26.7 | 40 | 53.3 | 66.7 | 80 |
| 2 mL | 7.5 mg/mL | 26.7 | 53.3 | 80 | 106.7* | 133.3* | 160* | |
| 3 mL | 5 mg/mL | 40 | 80 | 120* | 160* | 200* | 240* | |
| 20 mg | 1 mL | 20 mg/mL | 10 | 20 | 30 | 40 | 50 | 60 |
| 2 mL | 10 mg/mL | 20 | 40 | 60 | 80 | 100 | 120* | |
| 3 mL | 6.67 mg/mL | 30 | 60 | 90 | 120* | 150* | 180* | |
| 30 mg | 1 mL | 30 mg/mL | 6.67 | 13.3 | 20 | 26.7 | 33.3 | 40 |
| 2 mL | 15 mg/mL | 13.3 | 26.7 | 40 | 53.3 | 66.7 | 80 | |
| 3 mL | 10 mg/mL | 20 | 40 | 60 | 80 | 100 | 120* | |
* Over 100 units: more than a 1 mL syringe holds in one draw. † Under 2 units: hard to measure; more water makes the draw bigger. Arithmetic from the numbers in each row. Pepdex does not pick a dose for you.
What to know about Retatrutide before you mix it
Retatrutide is an investigational triple agonist from Eli Lilly that acts on the GLP-1, GIP and glucagon receptors. It is still in clinical trials and is not FDA-approved.
- How it is supplied
- There is no approved retatrutide product yet. Outside a clinical trial it turns up as freeze-dried powder in a vial, so it has to be mixed before use, and the mg on the label is the seller's claim rather than a checked figure.
- Common vial sizes
- 10 mg, 15 mg, 20 mg. Work from the mg printed on your own vial.
- Half-life
- About 6 days, which is why it is a once-a-week shot.
- Usual schedule on our page
- Once weekly.
- FDA status
- Investigational. In Phase 3 trials with Eli Lilly. Not yet approved.
- Evidence in one line
- About 24% mean body weight reduction at 48 weeks, highest dose. Source: Phase 2 trial, N Engl J Med 2023 (PMID 37366315).
What people track with Retatrutide
- Shot day and the amount, since it is usually stepped up every 4 weeks
- Weight and waist once a week
- Nausea or appetite changes in the days after a step-up
The common Retatrutide mix-up
Vial sizes run from 5 mg to 30 mg or more, so the same 2 mg shot is 40 units from a 10 mg vial mixed with 2 mL, and 20 units from a 20 mg vial mixed with 2 mL. Re-run the math whenever you start a vial of a different size.
Full Retatrutide entry: evidence, side effects, FDA and WADA status
How long a Retatrutide vial lasts
A 10 mg vial at 2 mg a shot holds 5 shots. Taken once a week, that is about 5 weeks. If your amount steps up before the vial is used up, it runs out sooner. Shots per vial for each size:
| Vial | At 2 mg | At 4 mg | At 6 mg | At 8 mg | At 10 mg | At 12 mg |
|---|---|---|---|---|---|---|
| 5 mg | 2 shots | 1 shot | under 1 | under 1 | under 1 | under 1 |
| 10 mg | 5 shots | 2 shots | 1 shot | 1 shot | 1 shot | under 1 |
| 15 mg | 7 shots | 3 shots | 2 shots | 1 shot | 1 shot | 1 shot |
| 20 mg | 10 shots | 5 shots | 3 shots | 2 shots | 2 shots | 1 shot |
| 30 mg | 15 shots | 7 shots | 5 shots | 3 shots | 3 shots | 2 shots |
Retatrutide reconstitution questions
- How much BAC water (reconstitution solution) do I add to a 10 mg Retatrutide vial?
- Any amount works for the math; it only changes the strength. 10 mg in 1 mL is 10 mg/mL, in 2 mL 5 mg/mL, and in 3 mL 3.33 mg/mL. More water gives a bigger draw that is easier to read. If your product came with mixing directions, those set the volume.
- How many units is 2 mg of Retatrutide?
- It depends on how much water is in the vial. From a 10 mg vial mixed with 2 mL, 2 mg is 40 units (0.4 mL). With 1 mL it is 20 units; with 3 mL, 60 units.
- How many 2 mg doses are in a 10 mg Retatrutide vial?
- 5. Taken once a week, that lasts about 5 weeks. If the amount steps up before the vial is used up, it runs out sooner. The water you add does not change the count, only the size of each draw.
- 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 a dose of one is not a dose of the other. The math on this page only depends on your vial's mg, the water and the amount you enter.
Related calculators
Educational reference. Pepdex does not sell peptides or recommend vendors. The calculator and charts convert amounts into syringe units; whether an amount is right for you is a question for a qualified provider.