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Tirzepatide

moderate risk

Also: Mounjaro · Zepbound

Strong Evidence FDA Approved

Tirzepatide is a dual GLP-1/GIP receptor agonist consistently outperforming semaglutide in trials. SURMOUNT-1: 20.9% weight loss. FDA approved as Mounjaro (T2D) and Zepbound (obesity). Current efficacy benchmark for GLP-1 class therapies.

Molecular Weight
4813.5 Da
Formula
C225H348N48O68
Common Dosing
2.5 mg/week SC titrating to 15 mg/week over 20 weeks
Category
therapeutic
Last Reviewed
2025-01-15

Reported Benefits

Weight loss

Strong Evidence 112 studies

SURMOUNT-1: 20.9% body weight loss at 72 weeks (15 mg). Superior to semaglutide in head-to-head.

Glycemic control

Strong Evidence 89 studies

SURPASS trials: HbA1c reductions of 2.0–2.3% — best in GLP-1 class.

Mechanism of Action

Dual GLP-1 and GIP receptor agonism. GIP agonism adds incremental insulin sensitization and adipose effects producing superior metabolic benefits.

Key Clinical Studies

Jastreboff et al. (SURMOUNT-1) (2022)

Phase III RCT · n=2539

PubMed →

20.9% mean weight loss at 72 weeks (15 mg dose)

Del Prato et al. (SURPASS-2) (2021)

Phase III RCT vs. semaglutide · n=1879

PubMed →

Superior HbA1c reduction and weight loss vs. semaglutide 1 mg

GLP-1 + GIP: Why It Matters

Adding GIP agonism produces greater appetite suppression and metabolic improvement beyond GLP-1 alone. Head-to-head against semaglutide: tirzepatide wins consistently on weight loss magnitude.

Weight loss ladder: Semaglutide ~15% → Tirzepatide ~21% → Retatrutide ~24% (Phase 2)

Regulatory Status

FDA Approved

FDA approved — Mounjaro (T2D), Zepbound (obesity)

Safety Profile

Side Effects

  • •Nausea
  • •Vomiting
  • •Diarrhea
  • •Pancreatitis (rare)
  • •Thyroid tumors (black box, animal data)

Contraindications

  • •MTC/MEN2 history
  • •Pregnancy

Drug Interactions

  • •Insulin/sulfonylureas
  • •Oral contraceptives

Primary Uses

Obesity/weight lossType 2 diabetesCardiovascular risk

Related Peptides

semaglutideretatrutideliraglutidecagrilintide

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Disclaimer: This information is for educational and research purposes only. Not medical advice. Consult a qualified healthcare provider before using any compound.