An investigational triple-hormone (GIP, GLP-1, glucagon) receptor agonist from Eli Lilly. It is not approved anywhere, and Health Canada lists it among unauthorized peptides being sold.
How strong is the human evidence?
- Cell & animal
- Small human studies
- Some randomized trials
- Large randomized trials
What is Retatrutide?
Retatrutide is a single peptide that activates GIP, GLP-1 and glucagon receptors. It is in Phase 3 trials.
Lilly says it has not been approved by any regulator and that anything sold to consumers outside its clinical trials is illegal and unverifiable.
Is Retatrutide legal in Canada?
Not authorized. Health Canada names retatrutide among unauthorized peptides it has found being sold, and among seized injectable products in its April 2026 advisory. The only legal access is enrolment in an authorized clinical trial.
What the research shows
- Phase 2 trial (Jastreboff et al., NEJM 2023): 338 adults with obesity or overweight; at 48 weeks, average weight change ranged from −8.7% (lowest dose group) to −24.2% (highest dose group) vs −2.1% with placebo.
What it doesn't show
- Phase 2 results are not approval. Long-term safety, including the cardiovascular outcomes trial, has not been reported.
- Products sold online are not the product used in Lilly's trials.
Common questions
Is retatrutide legal in Canada?
No. It is an investigational drug. Health Canada lists it among unauthorized peptides; it is only legally available inside an authorized clinical trial.
Is retatrutide approved by the FDA?
No. As of Lilly's September 2026 update it had not been approved by any regulator.
Are there retatrutide clinical trials in Canada?
Health Canada says people may access unauthorized peptides only through an approved clinical trial. Ask your doctor or search Health Canada's clinical trials database.
Sources
- Health Canada — Peptides: Overview
- Health Canada advisory RA-81874 (Apr 9, 2026): Think twice before injecting peptides bought online
- Health Canada — Peptides: Research and clinical trials
- Eli Lilly — What to know about retatrutide (updated Sep 2026)
- Jastreboff AM et al. Triple-hormone-receptor agonist retatrutide for obesity — a phase 2 trial. NEJM 2023
Related
TirzepatideA dual GIP/GLP-1 receptor agonist. Health Canada has authorized Mounjaro for type 2 diabetes and Zepbound for chronic…Authorized in Canada (prescription)
SemaglutideA GLP-1 receptor agonist peptide drug for type 2 diabetes and chronic weight management. In Canada it is a prescription…Authorized in Canada (prescription)