Retatrutide dosage calculator
Enter a vial and a dose and this returns the concentration, the volume and the syringe units. Underneath it, the same arithmetic worked out in advance for common vials, and the doses published studies of Retatrutide actually used, every one quoted and cited. It converts numbers. It does not suggest what to take.
Work out concentration and what to draw
Two divisions, both shown. Concentration = mass in the vial ÷ diluent volume. Volume to draw = mass you want ÷ that concentration. Syringe units are that volume × the units per millilitre on your syringe's own scale.
Worked example: 5 mg in 2 mL is 2,500 mcg/mL, so 250 mcg is 0.1 mL, which is 10 units on a U-100 syringe and 4 units on a U-40. The scale is printed on the barrel; reading a U-40 syringe as if it were U-100 is a two-and-a-half-fold error.
Retatrutide reconstitution chart
Units on a standard U-100 insulin syringe, where 100 units is 1 mL. The rows are the absolute doses quoted in studies of Retatrutide, from 1 mg to 12 mg, so this chart is specific to this compound rather than a generic ladder. More diluent means more units for the same dose, which is easier to measure accurately and empties the vial no faster.
| Dose | 1 mL diluent (2,000 mcg/mL) | 2 mL diluent (1,000 mcg/mL) | 3 mL diluent (667 mcg/mL) |
|---|---|---|---|
| 1 mg | 50 | 100 | 150 >1 mL |
| 2 mg | 100 | 200 >1 mL | 300 >1 mL |
| 4 mg | 200 >1 mL | 400 >1 mL | 600 >1 mL |
| 5 mg | 250 >1 mL | 500 >1 mL | 750 >1 mL |
| 8 mg | 400 >1 mL | 800 >1 mL | 1,200 >1 mL |
| 9 mg | 450 >1 mL | 900 >1 mL | 1,350 >1 mL |
| 12 mg | 600 >1 mL | 1,200 >1 mL | 1,800 >1 mL |
| Dose | 1 mL diluent (5,000 mcg/mL) | 2 mL diluent (2,500 mcg/mL) | 3 mL diluent (1,667 mcg/mL) |
|---|---|---|---|
| 1 mg | 20 | 40 | 60 |
| 2 mg | 40 | 80 | 120 >1 mL |
| 4 mg | 80 | 160 >1 mL | 240 >1 mL |
| 5 mg | 100 | 200 >1 mL | 300 >1 mL |
| 8 mg | 160 >1 mL | 320 >1 mL | 480 >1 mL |
| 9 mg | 180 >1 mL | 360 >1 mL | 540 >1 mL |
| 12 mg | 240 >1 mL | 480 >1 mL | 720 >1 mL |
| Dose | 1 mL diluent (10,000 mcg/mL) | 2 mL diluent (5,000 mcg/mL) | 3 mL diluent (3,333 mcg/mL) |
|---|---|---|---|
| 1 mg | 10 | 20 | 30 |
| 2 mg | 20 | 40 | 60 |
| 4 mg | 40 | 80 | 120 >1 mL |
| 5 mg | 50 | 100 | 150 >1 mL |
| 8 mg | 80 | 160 >1 mL | 240 >1 mL |
| 9 mg | 90 | 180 >1 mL | 270 >1 mL |
| 12 mg | 120 >1 mL | 240 >1 mL | 360 >1 mL |
Read a figure off this chart only if it matches the vial in front of you. A vial labelled a different strength, or reconstituted with a different volume, gives a different number for the same dose, and that is the single most common way these calculations go wrong.
Doses in published studies of Retatrutide
Each row is quoted from a paper in this compound's source ledger and carries the kind of evidence it came from. 6 of 6 come from human studies; the rest are animal or laboratory work.
| Evidence | Dose as the paper states it | Source |
|---|---|---|
| Human clinical trial | Randomized controlled trial, humans, n=930, 2026: doses stated in the abstract: 4 mg; 9 mg; 12 mg. Participants were randomly assigned (1:1:1:1) to receive retatrutide (4 mg, 9 mg, or 12 mg) or placebo by once-weekly subcutaneous injection. | pmid-42250575 |
| Human clinical trial | Clinical trial, humans, n=213, 2026: doses stated in the abstract: 12 mg. Intervention(s) Obesity trial; retatrutide (1, 4, 8, 12 mg) or placebo. | pmid-42135195 |
| Human clinical trial | Clinical trial, humans, n=40, 2025: doses stated in the abstract: 1 mg. Participants (N = 40; mean age 51 years; 52.5 % male) received retatrutide 4/8/12 mg (n = 23), retatrutide 1 mg (n = 13), or placebo (n = 4). | pmid-41216380 |
| Human clinical trial | Randomized controlled trial, humans, n=275, 2025: doses stated in the abstract: 4 mg. Compared with placebo, participants who received retatrutide ≥4 mg reported greater reductions from baseline in overall appetite, hunger, and prospective food consumption (l at Week 24 (all p Conclusions Perceived hunger and tendency to overeat… | pmid-40916752 |
| Human clinical trial | Randomized controlled trial, humans, n=534, 2025: doses stated in the abstract: 0·5 mg; 4 mg; 2 mg; 8 mg. Eligible participants were randomly assigned in a 2:2:2:1:1:1:1:2 ratio to once-weekly subcutaneous placebo, dulaglutide 1·5 mg, or retatrutide 0·5 mg, 4 mg (2 mg initial dose), 4 mg (4 mg initial dose), 8 mg (2 mg initial dose), 8… | pmid-40609566 |
| Human clinical trial | Clinical trial, humans, n=281, 2025: doses stated in the abstract: 0.5-12 mg; 12 mg; 8 mg. A post hoc analysis of 2 retatrutide studies (dose range: 0.5-12 mg) was performed in participants (estimated glomerular filtration rate [eGFR] ≥ 45 ml/min per 1.73 m 2 ) with T2D ( n = 281) and with overweight or obesity without T2D ( n = 338). | pmid-40630318 |
How long studies ran, and how far a vial goes
A vial lasts for a number of draws, not a number of weeks: divide the mass in the vial by the mass per draw and round down, which the vial planner does. How long that represents depends on frequency. For context, these are the durations studies of Retatrutide actually ran for.
- Clinical trial, humans, 2026: durations stated: 36 weeks; 48 weeks. In Study 1, adults with obesity/overweight and T2D received once-weekly retatrutide (0.5/4/8/12 mg), dulaglutide (1.5 mg) or placebo for 36 weeks; in Study 2, adults with clinical obesity without T2D received retatrutide (1/4/8/12 mg) or placebo for 48 weeks. pmid-42608321
- Clinical trial, humans, n=213, 2026: durations stated: 48 weeks. Participants living with obesity with and without T2D were treated for 36 and 48 weeks, respectively. pmid-42135195
- Clinical trial, humans, n=40, 2025: durations stated: 51 years; 8 weeks. Participants (N = 40; mean age 51 years; 52.5 % male) received retatrutide 4/8/12 mg (n = 23), retatrutide 1 mg (n = 13), or placebo (n = 4). pmid-41216380
- Randomized controlled trial, humans, n=275, 2025: durations stated: 36 weeks; 36 week. These pre-specified exploratory analyses examined changes from baseline in Appetite Visual Analogue Scale (VAS) and Eating Inventory (EI) scores after 24 and 36 weeks of once-weekly treatment with placebo, dulaglutide 1.5 mg, or retatrutide 0.5, 4, 8,… pmid-40916752
- Clinical trial, humans, 2024: durations stated: 6 days. The pharmacokinetics of retatrutide were dose proportional and its mean half-life of approximately 6 days supported a once-weekly dosing. pmid-39724554
Storage and stability, as published
Reconstitution starts a clock. These are the storage and stability conditions stated in papers in this ledger. They describe what the study did, which is not the same as a shelf life for a vial in your fridge.
- Animal study, mice, 2025: It is found that Retatrutide, an anti-obesity agent, inhibits HBP and YAP O-GlcNAcylation leading to increased YAP degradation through the deprivation of EIF3H-mediated deubiquitylation of YAP. pmid-39868848
How Retatrutide was given
The route changes what a dose means. The same number given intravenously and subcutaneously is not the same exposure.
- Randomized controlled trial, humans, n=930, 2026: administration by subcutaneous route reported. Participants were randomly assigned (1:1:1:1) to receive retatrutide (4 mg, 9 mg, or 12 mg) or placebo by once-weekly subcutaneous injection. pmid-42250575
- Randomized controlled trial, humans, n=534, 2025: administration by subcutaneous route reported. Eligible participants were randomly assigned in a 2:2:2:1:1:1:1:2 ratio to once-weekly subcutaneous placebo, dulaglutide 1·5 mg, or retatrutide 0·5 mg, 4 mg (2 mg initial dose), 4 mg (4 mg initial dose), 8 mg (2 mg initial dose), 8 mg (4 mg… pmid-40609566
- Randomized controlled trial, humans, n=98, 2024: administration by subcutaneous route reported. Here, in this randomized, double-blind, placebo-controlled trial, participants (n = 98) were randomly assigned to 48 weeks of once-weekly subcutaneous retatrutide (1, 4, 8 or 12 mg dose) or placebo. pmid-38858523
- Randomized controlled trial, humans, n=338, 2023: administration by subcutaneous route reported. Participants were randomly assigned in a 2:1:1:1:1:2:2 ratio to receive subcutaneous retatrutide (1 mg, 4 mg [initial dose, 2 mg], 4 mg [initial dose, 4 mg], 8 mg [initial dose, 2 mg], 8 mg [initial dose, 4 mg], or 12 mg [initial dose, 2… pmid-37366315
- Human study, humans, n=5,800, 2026: administration by subcutaneous route reported. TRIUMPH consists of four Phase 3, multicenter, randomized, double-blind studies assessing weekly subcutaneous retatrutide compared to placebo, in conjunction with healthy diet and physical activity in over 5800 participants. pmid-41090431
- Animal study, 2026: administration by oral route reported. Recent evidence reinforces this framework: the SOUL trial established cardiovascular superiority for oral semaglutide, extending disease-modifying properties beyond injectable formulations, while Phase 3 TRIUMPH data position retatrutide as an emerging triple-agonist candidate… pmid-42649514
Questions people ask
- How many units is 1 mg of Retatrutide?
- It depends entirely on how the vial was reconstituted. In a 5 mg vial with 2 mL of diluent it is 40 units on a U-100 syringe; with 1 mL it is 20. The chart above gives the rest.
- Does adding more diluent waste the peptide?
- No. The mass in the vial does not change. More diluent spreads the same mass through more liquid, so each dose is a larger, easier-to-measure volume and the vial yields exactly as many doses as before.
- Why does this page not recommend a dose?
- Because a dose is a clinical decision rather than a division. It depends on why someone is taking something, what else they take and how their kidneys and liver are working, none of which is knowable from a number typed into a box.
- Where do the doses in the table come from?
- Each is quoted from a specific paper indexed in Europe PMC, linked in the source column, and labelled with the kind of study it came from. The full evidence is on the Retatrutide record.
What this calculator will not do
It will not take a body weight and return a milligram figure, and it will not tell you how often to draw. The table above is the published record, not a menu. A dose that appeared in a trial appeared under supervision, with monitoring, in people selected for that trial.
Other calculators
- Generic reconstitution calculatorThe same arithmetic, without a compound attached
- Unit convertermg, mcg, ng and syringe units
- Vial plannerDraws per vial and how long it lasts
- All compound calculatorsEvery compound with published dose figures