Semaglutide vs Tirzepatide vs Retatrutide: Complete GLP-1 Comparison
The ultimate GLP-1 comparison: semaglutide (single), tirzepatide (dual), and retatrutide (triple agonist). Weight loss data, mechanisms, availability, and cost.
| Dimension | semaglutide | tirzepatide | retatrutide | Notes |
|---|---|---|---|---|
| Weight Loss | 15-17% | 20-26% | 24-26% | Progressive improvement from single to triple agonist. Retatrutide Phase 2 data rivals tirzepatide. |
| Receptors | GLP-1 | GLP-1 + GIP | GLP-1 + GIP + Glucagon | Each generation adds a receptor. More receptors = more metabolic pathways activated. |
| FDA Status | Approved | Approved | Phase 3 | Semaglutide and tirzepatide available now. Retatrutide expected 2026-2027. |
| Safety Data | Extensive | Growing | Limited | Safety confidence inversely correlated with novelty. Semaglutide has most post-market data. |
| Cost (Brand) | $1,000+/mo | $1,000+/mo | N/A | Brand-name GLP-1s are expensive. Retatrutide not yet commercially available. |
Learn more about each peptide
Semaglutide
Semaglutide is a GLP-1 receptor agonist originally developed for type 2 diabetes that has demonstrated significant weight loss effects in clinical trials. It is sold under the brand names Ozempic (diabetes) and Wegovy (weight management).
Tirzepatide
Tirzepatide is a dual GIP/GLP-1 receptor agonist that has shown greater weight loss than semaglutide in head-to-head trials. It is sold under the brand names Mounjaro (diabetes) and Zepbound (weight management).
Retatrutide
Retatrutide is a triple hormone receptor agonist (GIP/GLP-1/glucagon) currently in Phase 3 clinical trials. Early data shows up to 24% body weight loss, potentially making it the most effective weight loss peptide ever studied.
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Reviewed by Fat Man in the Arena · Updated March 2026
Medical Disclaimer: This comparison is for informational purposes only. Individual responses vary. Always consult a qualified healthcare provider before starting any peptide protocol.