How it works
Simultaneously activates GLP-1, GIP and glucagon receptors in a single peptide. The glucagon component increases energy expenditure and hepatic lipid oxidation, while GLP-1 and GIP suppress appetite, slow gastric emptying and improve glucose-dependent insulin secretion.
Structure: 39 amino acid triple GIP / GLP-1 / glucagon receptor agonist
Reported benefits
- Up to ~24% mean weight loss at 12 mg over 48 weeks in phase 2
- Large reductions in HbA1c and liver fat
- Improvements in blood pressure, triglycerides and LDL cholesterol
Practical considerations
- Still investigational; long-term cardiovascular and safety data are pending
- Muscle-loss and GI tolerability concerns mirror semaglutide and tirzepatide
- Dose must be escalated slowly to improve tolerability
Side effects and risks
- Nausea and vomiting
- Diarrhoea
- Gallbladder issues
- Mild resting heart-rate increase
- Injection-site reaction
Retatrutide dosing overview
Phase 2 started at 2 mg weekly and escalated to 12 mg over several weeks
| Context | Amount | Frequency | Route |
|---|---|---|---|
| Phase 2 starting dose | 2 mg | Weekly | Subcutaneous |
| Phase 2 escalation | 4 → 8 → 12 mg | Stepwise over several weeks | Subcutaneous |
This describes doses reported in published literature and community protocols. It is not a recommendation, and it is not a substitute for clinical supervision.
Retatrutide FAQ
Is retatrutide available?
No. It is investigational and still in phase 3 as of 2026. Anything sold as retatrutide outside a trial is an unregulated research chemical of unverified identity and purity.
What makes it a triple agonist?
It activates GLP-1, GIP and glucagon receptors. The glucagon arm is the addition — it raises energy expenditure rather than only reducing intake.
How much weight loss was seen in trials?
The phase 2 obesity trial reported roughly 24% mean weight reduction at 48 weeks on the highest dose, the largest figure published for an incretin agent to date.
What are the reported side effects?
Predominantly gastrointestinal and dose-related, with increased heart rate and dose-dependent liver enzyme changes also noted in phase 2.
Research references
- Rosenstock et al., 2023 — Retatrutide for obesity in adults, phase 2, NEJM