Retatrutide (GLP-3) Dosage Guide: Reported Ranges, Units & Reconstitution
Reported Retatrutide (GLP-3) study arms, mg-to-insulin-unit conversion tables, reconstitution volumes and handling notes.
By PX1 Research Team · August 4, 2026
Retatrutide (GLP-3) amounts reported in the literature
Retatrutide (GLP-3) is a GIP/GLP-1/glucagon triple receptor agonist studied in metabolic and body-composition research. The table below summarizes the arms described in published protocols. It is a literature reference, not a protocol to follow.
| Study arm | Reported amount | Cadence |
|---|---|---|
| Initiation | 1 mg | weekly × 4 |
| Step 1 | 2 mg | weekly × 4 |
| Step 2 | 4 mg | weekly × 4 |
| Step 3 | 8 mg | weekly × 4 |
| Maximal arms | 12 mg | weekly |
Concentration math
Standard preparation: 10 mg + 2 mL bacteriostatic water = 5 mg/mL. On a U-100 insulin syringe, 100 units = 1 mL, so:
| Concentration | 0.5 mg | 1 mg | 2 mg | 5 mg |
|---|---|---|---|---|
| 2.5 mg/mL | 20 units | 40 units | 80 units | — |
| 5 mg/mL | 10 units | 20 units | 40 units | 100 units |
| 10 mg/mL | 5 units | 10 units | 20 units | 50 units |
Change the diluent volume and every number changes proportionally. The peptide calculator does the conversion for any vial size and target amount.
Why escalation intervals in the literature are long
Across published protocols in this class, step-ups are spaced in multi-week blocks rather than compressed. Study designs prioritize tolerability data at each level before advancing, which is why the reported schedules look conservative compared to what circulates informally.
Handling notes specific to Retatrutide (GLP-3)
| Property | Detail |
|---|---|
| Compound | Retatrutide (GLP-3) (LY3437943) |
| Class | GIP/GLP-1/glucagon triple receptor agonist |
| Molecular weight | 4731 g/mol |
| Reported half-life | ~6 days |
| Vial sizes | 10 mg / 15 mg / 20 mg / 30 mg |
| Purity | ≥99% HPLC · LC-MS identity · COA per lot |
| Form | Lyophilized powder |
Reconstituted material belongs at 2–8 °C with a 28-day in-use window using bacteriostatic water. Use a fresh needle for each draw and never re-enter a vial with a used tip.
Documentation
PX1 publishes HPLC purity, LC-MS identity and endotoxin data per lot at /coa. Product page: Retatrutide (GLP-3).
Research use only. PX1 Research supplies compounds for laboratory and in-vitro research. Nothing here is medical advice, a dosing recommendation, or an offer for human or veterinary use. Figures cited are reported from published laboratory literature.