Tirzepatide

Mounjaro · Zepbound

Rank#999
Weight LossApprovedApprovedPrescriptionSubQ

Popular for:Weight loss, type 2 diabetes, dual GIP/GLP-1 agonist

1821

Total Studies

994

Human Studies

Approved

Evidence Level

Approved

FDA Status

Overview

Tirzepatide is a dual GIP/GLP-1 receptor agonist developed by Eli Lilly and marketed as Mounjaro (for type 2 diabetes) and Zepbound (for obesity). It is the first-in-class dual incretin agonist, and represents one of the most significant advances in obesity and diabetes treatment. It achieved up to 22.5% weight loss in Phase 3 trials.

**Originally developed for: **Type 2 diabetes (Mounjaro, FDA approved May 2022). Subsequently approved for chronic weight management (Zepbound, FDA approved November 2023).

Mechanism of Action

Tirzepatide activates both GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptors. GLP-1 agonism reduces appetite, slows gastric emptying, and enhances insulin secretion. GIP agonism further improves insulin sensitivity and may enhance fat metabolism. The dual action provides superior glycemic control and weight loss compared to GLP-1 agonists alone.

Key Research Benefits

Primary Benefits:

Superior weight loss — Up to 22.5% in Phase 3 trials, exceeding semaglutide (SURMOUNT-1, NEJM 2022)
Excellent glycemic control — HbA1c reductions of 2.0-2.6% in SURPASS trials
Cardiovascular risk reduction — SURPASS-CVOT showed 10% reduction in major adverse cardiovascular events
Improved lipid profile — Reduces triglycerides, improves HDL/LDL ratio

Secondary Benefits:

Blood pressure reduction
Liver fat reduction (being studied for MASLD/NAFLD)
Sleep apnea improvement (SURMOUNT-OSA trial showed significant AHI reduction)

Clinical Evidence Summary

Research Pipeline

Preclinical
Animal
Phase I
Phase II
Phase III
Approved

1821

Total Studies

994

Human Studies

- SURPASS trials (1-5) — Comprehensive Phase 3 program for type 2 diabetes. Demonstrated superior HbA1c reduction vs. semaglutide, insulin degludec, and insulin glargine.

- SURMOUNT-1 (NEJM, 2022) — Phase 3 obesity trial. 2,539 participants. 15 mg dose: 22.5% weight loss at 72 weeks. One of the largest weight loss results ever seen in a clinical trial.

- SURMOUNT-OSA — Demonstrated significant improvement in obstructive sleep apnea severity.

- FAERS analysis (PMC, 2025) — Real-world safety data from FDA adverse event reporting. Confirmed known GI side effects as most common.

> Clinical trial status: FDA APPROVED. Mounjaro (type 2 diabetes, May 2022). Zepbound (chronic weight management, November 2023). Extensive Phase 3 data. Active post-marketing surveillance.

Key Studies / PubMed References

1,821 studies found on PubMed · showing top 25 by relevance

View all on PubMed

Tirzepatide for Obesity Treatment and Diabetes Prevention.

Human Study

Jastreboff AM, le Roux CW, Stefanski A, et al. · The New England journal of medicine · 2025

PMID: 39536238

Tirzepatide as Compared with Semaglutide for the Treatment of Obesity.

Human Study

Aronne LJ, Horn DB, le Roux CW, et al. · The New England journal of medicine · 2025

PMID: 40353578

Tirzepatide for overweight and obesity management.

Review

Hamza M, Papamargaritis D, Davies MJ · Expert opinion on pharmacotherapy · 2025

PMID: 39632534

Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 Diabetes.

Human Study

Nicholls SJ, Pavo I, Bhatt DL, et al. · The New England journal of medicine · 2025

PMID: 41406444

Tirzepatide did not impact metabolic adaptation in people with obesity, but increased fat oxidation.

Human Study

Ravussin E, Sanchez-Delgado G, Martin CK, et al. · Cell metabolism · 2025

PMID: 40203836

Side Effects & Safety

Common Side Effects:

Nausea (most common, especially during titration — 12-33% in trials)
Diarrhea (12-23%)
Constipation
Decreased appetite (intended but can be excessive)
Injection site reactions

Rare but Serious Risks:

Pancreatitis (GLP-1 class concern)
Thyroid C-cell tumors (boxed warning — based on rodent data)
Gallbladder disease — cholelithiasis with rapid weight loss
Hypoglycemia (when combined with insulin or sulfonylureas)

> Boxed Warning: Thyroid C-cell tumors in rodents. Contraindicated in personal/family history of medullary thyroid carcinoma or MEN2. Not for type 1 diabetes. Caution with history of pancreatitis. May delay absorption of oral medications.

Known Interactions

No curated interaction entry is live for Tirzepatide yet.

Until the interaction table is fully populated, use the interaction checker and related peptides below to explore adjacent compounds and likely research pairings.

Frequently Asked Questions

Research Disclaimer

This page is for research and educational purposes only. The information presented is based on published scientific literature and does not constitute medical advice, diagnosis, or treatment recommendations. Tirzepatide is not approved by the FDA for human therapeutic use. Always consult a qualified healthcare professional before making any health-related decisions. The studies referenced are linked to their original PubMed sources for verification.