Retatrutide vs Tirzepatide

A triple agonist of GIP, GLP-1, and glucagon receptors in late-stage clinical trials, producing ~24% weight loss at 48 weeks in Phase 2 — the largest effect size of any weight-loss pharmaceutical to date.

A dual GIP and GLP-1 receptor agonist producing the largest sustained weight reductions of any drug currently licensed, averaging 20–22% body weight loss in clinical trials.

Retatrutide simultaneously activates three incretin/metabolic receptors. The addition of glucagon agonism is thought to increase energy expenditure, complementing the appetite suppression driven by GIP and GLP-1.

Tirzepatide activates both GIP and GLP-1 receptors, a combination that appears to amplify glucose-dependent insulin secretion, slow gastric emptying, and suppress appetite beyond what either pathway achieves alone.

Phase 2 used 1–12 mg weekly; optimal dose pending Phase 3

2.5 mg weekly, titrated up to 15 mg weekly

~6 days

~5 days

Subcutaneous once weekly

Subcutaneous once weekly

investigational

approved

Not yet listed

Not yet listed