Retatrutide
aka LY3437943 · triple-G agonist
An investigational triple agonist of GIP, GLP-1, and glucagon receptors that produced roughly 24% weight loss at 48 weeks in Phase II — the highest figure yet reported for a pharmacologic agent.
Mechanism of action
Adds glucagon-receptor agonism to the dual incretin approach, increasing energy expenditure and hepatic fat oxidation on top of appetite suppression and insulin sensitization.
Doses used in published studies
Phase II: 1, 4, 8, and 12 mg once weekly with escalation.
These figures describe what researchers administered under supervision. They are reported for accuracy and are not a protocol, recommendation, or substitute for clinical guidance.
Reported benefits
- 24.2% mean weight reduction at 48 weeks on 12 mg
- Near-complete resolution of hepatic steatosis in a substudy
- Strong HbA1c reductions in type 2 diabetes cohorts
Risks & unknowns
- GI adverse events dose-dependent and common
- Heart-rate increases attributed to glucagon agonism
- No Phase III outcome or long-term safety data published yet
Legal & regulatory status
Not approved anywhere. Available only through registered clinical trials; any consumer sale is illicit.
Check status in your state or country →Key studies
- Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial
New England Journal of Medicine · 2023