Retatrutide dosage calculator
Retatrutide is an investigational GIP, GLP-1 and glucagon receptor agonist; it is not an approved medicine. Research vials are sold as lyophilised powder, most often 10, 20 or 30 mg, so the same milligram figure lands on very different syringe marks depending on the vial and the water added. The calculator below does that conversion; the tables show the arithmetic for common vials and for the doses used in the published phase 2 trials.
Full research profile: Retatrutide. For any other concentration, use the insulin syringe units converter.
For research use only. Not medical advice. This page does arithmetic; it does not recommend an amount.
Retatrutide reconstitution chart
Concentration and micrograms per mark on a U-100 insulin syringe, by vial size and water added. The peptide amount never changes; only how concentrated it is.
| Vial | + 1 mL water | + 2 mL water | + 3 mL water |
|---|---|---|---|
| 10 mg | 10 mg/mL · 100 mcg per unit | 5 mg/mL · 50 mcg per unit | 3.33 mg/mL · 33.3 mcg per unit |
| 20 mg | 20 mg/mL · 200 mcg per unit | 10 mg/mL · 100 mcg per unit | 6.67 mg/mL · 66.7 mcg per unit |
| 30 mg | 30 mg/mL · 300 mcg per unit | 15 mg/mL · 150 mcg per unit | 10 mg/mL · 100 mcg per unit |
Most-listed Retatrutide vial sizes across vendors we track: 10 mg (22 vendors), 20 mg (13 vendors), 30 mg (13 vendors), 60 mg (9 vendors). Compare prices.
Retatrutide doses from the label and trials, in syringe units
The doses reported in each cited source, converted to U-100 syringe units at common vial and water combinations. This is arithmetic on the cited figures, not a recommendation; a dash means the amount is more than one full 1 mL syringe at that concentration.
Phase 2 obesity trial, once weekly (adults with obesity, n=338)
| Dose | 10 mg + 2 mL (5 mg/mL) | 20 mg + 2 mL (10 mg/mL) | 30 mg + 3 mL (10 mg/mL) |
|---|---|---|---|
| 1 mg | 20 units (0.2 mL) | 10 units (0.1 mL) | 10 units (0.1 mL) |
| 4 mg | 80 units (0.8 mL) | 40 units (0.4 mL) | 40 units (0.4 mL) |
| 8 mg | — | 80 units (0.8 mL) | 80 units (0.8 mL) |
| 12 mg | — | — | — |
Common questions
How many units is 1 mg of Retatrutide?
It depends on the concentration. In a 10 mg vial mixed with 2 mL of bacteriostatic water (5 mg/mL), 1 mg is 0.2 mL, or 20 units on a U-100 insulin syringe. With 3 mL of water instead, the same 1 mg is 30 units.
How much bacteriostatic water do you add to a 10 mg Retatrutide vial?
There is no single correct volume: the amount of peptide is fixed and the water only sets the concentration. For 10 mg, 1 mL gives 10 mg/mL (100 mcg per unit), 2 mL gives 5 mg/mL (50 mcg per unit) and 3 mL gives 3.33 mg/mL (33.3 mcg per unit). More water makes each syringe mark hold less, which makes small amounts easier to measure accurately.
Are the Retatrutide doses on this page recommendations?
No. They are the doses reported in the cited source (Jastreboff AM et al. N Engl J Med. 2023), converted to syringe units as arithmetic. Approved products come in their own strengths and devices, and what any person should use is a decision for a licensed clinician.
What does one unit on an insulin syringe mean?
A unit is a volume mark, not an amount of drug. On a U-100 syringe 100 units fill 1 mL, so 10 units is always 0.1 mL; how much peptide those 10 units hold depends only on the concentration you mixed. U-40 syringes use 40 marks per mL, so the same volume reads as a different number of units.