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GLP-1 Comparison Matrix

A comprehensive, side-by-side comparison of the three major GLP-1 receptor agonist peptides covered in this database: Tirzepatide, Retatrutide, and Semaglutide.


Overview

Feature Tirzepatide Retatrutide Semaglutide
Brand Name Mounjaro / Zepbound Unnamed (investigational) Ozempic / Wegovy / Rybelsus
Developer Eli Lilly Eli Lilly Novo Nordisk
Class GIP/GLP-1 dual agonist GIP/GLP-1/GCGR triple agonist Selective GLP-1 agonist
FDA Approval Yes (2022 T2D, 2023 obesity) Investigational (Phase 3) Yes (2017 T2D, 2021 obesity)
Route SC weekly SC weekly SC weekly / Oral daily
Half-life ~5 days ~6 days ~7 days

Chemical Profile Comparison

Property Tirzepatide Retatrutide Semaglutide
CAS Number 2023788-19-2 2381089-83-3 910463-68-2
Molecular Formula C₂₂₅H₃₄₈N₄₈O₆₈ C₂₂₈H₃₅₄N₄₆O₆₈ C₁₈₇H₂₉₁N₄₅O₅₉
Molecular Weight 4813.45 g/mol 4840.58 g/mol 4113.58 g/mol
Sequence Length 39 amino acids 39 amino acids 31 amino acids
Fatty Acid Modification C20 diacid C20 diacid C18 diacid
Purity (HPLC) ≥ 98% ≥ 98% ≥ 98%

Receptor Pharmacology Comparison

Receptor Tirzepatide Retatrutide Semaglutide
GLP-1R EC50 0.06 nM 0.09 nM 0.04 nM
GIPR EC50 0.29 nM 0.12 nM Inactive
GCGR EC50 Inactive 0.26 nM Inactive
Receptor Activation Profile Balanced GIP/GLP-1 Balanced triple agonist Selective GLP-1

Pharmacokinetic Comparison

Parameter Tirzepatide Retatrutide Semaglutide
Bioavailability (SC) ~80% ~75% ~89%
Tmax 8–24 h 12–24 h 12–24 h
Volume of Distribution ~0.3 L/kg ~0.25 L/kg ~0.3 L/kg
Protein Binding ~99% ~99% ~99%
Metabolism Proteolytic Proteolytic Proteolytic
Elimination Renal/Fecal Renal/Fecal Renal/Fecal

Clinical Efficacy Comparison

Endpoint Tirzepatide (15 mg) Retatrutide (12 mg) Semaglutide (2.4 mg)
HbA1c Reduction (T2D) 2.1–2.4% 1.6–2.2% (Phase 2) 1.5–1.9%
Body Weight Reduction (T2D) 11–15% 10–15% (Phase 2) 6–10%
Body Weight Reduction (Metabolic Research) 15–22.5% 17.5% 14.9%
MACE Reduction Ongoing trials Ongoing trials 20–26% reduction
Onset of Action 2–4 weeks 2–4 weeks 2–4 weeks
Max Effect (Weight) 40–60 weeks 48–72 weeks 60–68 weeks

Safety Profile Comparison

Adverse Event Tirzepatide Retatrutide Semaglutide
Nausea 17–30% 20–38% 20–44%
Diarrhea 13–23% 15–28% 13–28%
Vomiting 6–10% 8–15% 5–15%
Pancreatitis ~0.2% < 0.3% 0.1–0.3%
Gallbladder events ~0.4% ~0.5% 0.5–1.5%
Heart rate increase 2–4 bpm 2–4 bpm 2–4 bpm
Discontinuation (GI) ~5–8% ~7–12% ~5–10%

Dosing Comparison

Parameter Tirzepatide Retatrutide Semaglutide
Starting Dose 2.5 mg/week 1 mg/week 0.25 mg/week
Maintenance Dose Range (Research) 5–15 mg/week 4–12 mg/week 1.0–2.4 mg/week
Dose Escalation Every 4 weeks Every 4 weeks Every 4 weeks
Max Dose (Research) 2.0 mg/week 1.2 mg/week 2.4 mg/week
Administration SC injection SC injection SC injection / Oral

Selection Considerations

Choose Tirzepatide when:

  • Research requires both GIP and GLP-1 receptor activation
  • Superior weight loss efficacy is the primary endpoint
  • Head-to-head comparison against selective GLP-1 agonism

Choose Retatrutide when:

  • Triple receptor activation is of research interest
  • Studying the glucagon receptor contribution to energy expenditure
  • Investigating maximal weight loss potential

Choose Semaglutide when:

  • A well-characterized selective GLP-1 agonist is needed
  • Cardiovascular outcome research is the focus
  • Oral administration route is required

Analytical Method Comparison

Parameter Tirzepatide Retatrutide Semaglutide
HPLC Gradient 20–60% B (30 min) 25–65% B (30 min) 20–60% B (30 min)
Retention Time ~14–16 min ~15–17 min ~13–15 min
Column C18 (4.6×250 mm) C18 (4.6×250 mm) C18 (4.6×250 mm)
Detection UV 214 nm UV 214 nm UV 214 nm
MS Ionization ESI+ ESI+ ESI+
Charge States +4 to +8 +4 to +8 +3 to +7

References

  1. Coskun T, et al. (2018). Dual GIP/GLP-1 agonist tirzepatide. Diabetes. DOI: 10.2337/db18-0027
  2. Coskun T, et al. (2022). Triple agonist retatrutide. Nature Metabolism. DOI: 10.1038/s42255-022-00647-2
  3. Frias JP, et al. (2021). Tirzepatide vs semaglutide (SURPASS-2). The Lancet. DOI: 10.1016/S0140-6736(21)01324-6
  4. Jastreboff AM, et al. (2022). Tirzepatide for obesity (SURMOUNT-1). NEJM. DOI: 10.1056/NEJMoa2206038
  5. Jastreboff AM, et al. (2023). Retatrutide for obesity management. NEJM. DOI: 10.1056/NEJMoa2301972
  6. Marso SP, et al. (2016). Semaglutide CV outcomes (SUSTAIN-6). NEJM. DOI: 10.1056/NEJMoa1607141
  7. Wilding JPH, et al. (2021). Semaglutide for obesity (STEP-1). NEJM. DOI: 10.1056/NEJMoa2032183

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