The DriveDr Peter AttiaAired 2026-03-12

Peter Attia — The GLP-1 episode: tirzepatide, retatrutide, and the obesity pharmacology revolution

Attia's deep-dive on GIP/GLP-1/glucagon agonists — why tirzepatide displaced semaglutide, what retatrutide adds, and when orforglipron changes the economics.

Why this episode mattered

Peter Attia sets the standard for translating complex pharmacology into practitioner-grade guidance. This episode became the go-to reference for clinicians onboarding GLP-1 therapy in 2026.

Headline takeaways

Tirzepatide's dual GIP/GLP-1 mechanism consistently outperforms semaglutide in RCTs — SURMOUNT-2 delivered 22.5% mean weight loss.
Retatrutide's Phase 2 data (28.7% weight loss, still trending down at 48 weeks) suggests the triple-agonist era is real.
Orforglipron — Lilly's oral GLP-1 — isn't more effective, but it obliterates the injection moat.
Cagrilintide is the overlooked amylin analogue that adds modest additional weight loss as an add-on to semaglutide.