Incretin regulatory timeline: approvals, evidence, and retatrutide status.

Semaglutide and tirzepatide are active ingredients in FDA-approved prescription products for specific indications. Retatrutide remains an investigational Lilly compound and is not approved by the FDA or another regulatory agency.

Approved branded medicines, investigational drug-development programs, and laboratory research materials are separate categories with different evidence, manufacturing, labeling, and regulatory requirements.

• Semaglutide: mature human evidence and multiple approved branded prescription contexts.
• Tirzepatide: FDA-approved branded prescription contexts include specific metabolic indications and, as of December 20, 2024, obstructive sleep apnea in adults with obesity.
• Retatrutide: successful phase 3 trials reported, additional trials underway, and no regulatory approval as of this article update.

Lilly's June 2026 update reports successful completion of TRIUMPH-4, TRIUMPH-1, and TRANSCEND-T2D-1. Additional TRIUMPH and TRANSCEND-T2D trials remain underway across several research questions.

Topline or published phase 3 results are evidence milestones, not regulatory approvals. Approval requires a completed regulatory review for a specific product and indication.

The public-policy conversation is also active. Pew summarized U.S. public opinion and coverage limits in early 2026, while WHO and PAHO emphasized both the clinical importance of GLP-1 medicines and the need for access frameworks, pharmacovigilance, and caution around misuse.

Those discussions concern regulated medicines and public-health systems. They do not establish medical use, dosing, safety, or efficacy for a laboratory research product.

FDA approval of a branded prescription medicine does not validate unapproved, compounded, imported, or research-use versions for human use. It also does not create dosing guidance for a research-use product. This overview organizes public evidence and status; it does not recommend use.