Retatrutide — dosage (investigational)
Retatrutide (LY3437943) is an investigational triple GIP/GLP-1/glucagon receptor agonist studied for obesity and type 2 diabetes. It is not an approved medicine. The text below reproduces a published clinical-trial protocol for reference only and is not a usage recommendation.
mg → units reference (math only)
Pure arithmetic for the example reconstitution below: how many units on a U-100 insulin syringe a given dose corresponds to. units = doseMg ÷ (vialMg ÷ bacMl) × 100. These are unit conversions, not a dosing recommendation.
| Dose | Units (U-100) | Volume |
|---|---|---|
| 1 mg | 10.0 U | 0.100 mL |
| 2 mg | 20.0 U | 0.200 mL |
| 4 mg | 40.0 U | 0.400 mL |
| 8 mg | 80.0 U | 0.800 mL |
| 12 mg | 120.0 U | 1.200 mL |
Published titration / dose schedule
In the published Phase 2 obesity trial, the protocol would have started participants in the higher-dose groups at a low initial dose and escalated every 4 weeks to improve tolerability:
According to the published Phase 2 protocol, participants assigned to the higher maintenance groups (4, 8 or 12 mg once weekly) would have begun at an initial dose of 2 mg or 4 mg, with the dose being increased every 4 weeks over up to 12 weeks until the assigned maintenance dose was reached — for example, a 12 mg group would have escalated 2 mg → 4 mg → 8 mg → 12 mg in four-week steps. The report noted that starting at 2 mg produced fewer gastrointestinal effects than starting at 4 mg while achieving comparable weight reduction at 48 weeks. These figures describe a study protocol only; retatrutide has no approved dosing and is not authorised for use outside clinical trials.
Sources
- Jastreboff et al., Retatrutide Phase 2 (obesity), NEJM 2023
- PubMed — Phase 2 trial (PMID 37366315)
- ClinicalTrials.gov — TRIUMPH Phase 3 programme
As of: June 21, 2026
Neutral tools
Need the math for your own setup? Use the neutral, drug-agnostic tools — they come with no pre-loaded "recommended" dose.