Tirzepatide

Overview

Tirzepatide is a unimolecular dual GIP and GLP-1 receptor agonist with a half-life of approximately 5 days, enabling once-weekly subcutaneous dosing. It is FDA-approved as Mounjaro for type 2 diabetes (2022), Zepbound for chronic weight management in adults with obesity or overweight with a weight-related comorbidity (2023), and Zepbound for moderate-to-severe obstructive sleep apnea in adults with obesity (2024). It carries a BOXED WARNING for thyroid C-cell tumors and is contraindicated in patients with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).

Mechanism of Action

Tirzepatide is a 39-amino-acid synthetic peptide that co-activates the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. GLP-1R activation enhances glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and reduces appetite via central satiety pathways; GIP receptor agonism augments insulin secretion, improves adipose tissue lipid handling, and may blunt GLP-1-mediated nausea — producing greater A1C and weight-loss effects than selective GLP-1 agonists.

Research Summary

The SURPASS program established efficacy in type 2 diabetes, including SURPASS-2 (Frias et al., NEJM 2021), in which tirzepatide was superior to semaglutide 1 mg for A1C reduction and body weight. The SURMOUNT-1 obesity trial (Jastreboff et al., NEJM 2022) demonstrated up to approximately 20.9% mean body-weight reduction at 15 mg over 72 weeks. SURMOUNT-OSA (Malhotra et al., NEJM 2024) showed large reductions in apnea-hypopnea index in obstructive sleep apnea with obesity, supporting the 2024 FDA indication (Zepbound for moderate-to-severe OSA in adults with obesity). The SUMMIT trial (Packer et al., NEJM 2025) demonstrated a lower risk of cardiovascular death or worsening heart failure in HFpEF with obesity.

Vendors selling Tirzepatide

Scored vendors carrying Tirzepatide, ranked by trust grade. Grades are computed from indexed Certificates of Analysis. Full $/mg pricing is on the comparison page.

Prescribers who offer Tirzepatide

347 prescribers in our directory work with Tirzepatide, each confirmed from their own website. Peptides like Tirzepatide require a prescription from a licensed provider — telehealth options are available.

Reported Side Effects

• Nausea (most common, dose-dependent)
• Vomiting
• Diarrhea
• Constipation
• Abdominal pain and dyspepsia
• Decreased appetite
• Injection-site reactions
• Acute pancreatitis (discontinue if suspected)
• Gallbladder disease and cholelithiasis
• Hypoglycemia when combined with insulin or sulfonylureas
• Acute kidney injury related to volume depletion from severe GI losses
• Hypersensitivity reactions, including rare anaphylaxis and angioedema
• Diabetic retinopathy complications in patients with pre-existing retinopathy

Biomarkers researchers track for Tirzepatide

These biomarkers appear in the research literature as measures of response and safety for this compound.

Related Peptides

Compare Tirzepatide with Others

Research References

• Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine. 2022;387(3):205-216. PMID 35658024.
• Frías JP, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). New England Journal of Medicine. 2021;385(6):503-515. PMID 34170647.
• Malhotra A, et al. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA). New England Journal of Medicine. 2024;391(13):1193-1205. PMID 38912654.
• Packer M, et al. Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity (SUMMIT). New England Journal of Medicine. 2025;392(5):427-437. PMID 39555826.

Frequently asked questions

Has Tirzepatide been independently lab-tested?

Disclosed Labs has collected 375 Certificates of Analysis (COA) for Tirzepatide from 16 independent testing labs. 52 vendors have submitted material for testing. Products average 99.6% tested purity across the corpus. Full testing data is available at https://www.disclosedlabs.com/peptides/tirzepatide/testing.

What is the average purity of Tirzepatide on the market?

Based on 375 COAs analyzed by Disclosed Labs, Tirzepatide products average 99.6% (±1.7%) tested purity. Individual vendor results vary; see per-vendor COA data at https://www.disclosedlabs.com/peptides/tirzepatide/coas.

Which labs have tested Tirzepatide?

Independent labs that have tested Tirzepatide include: ILS Labs (Grade A), Ethos Analytics (Grade B). Full lab credibility grades and profiles are at https://www.disclosedlabs.com/labs.

Where can researchers source Tirzepatide?

8 vendors with Disclosed Labs trust grades currently list Tirzepatide, including Glacier Aminos, Ion Peptide, Voltera Sciences. Compare live prices and lab-verified COAs at https://www.disclosedlabs.com/prices/tirzepatide.

Which prescribers offer Tirzepatide with a prescription?

347 prescribers in the Disclosed Labs directory work with Tirzepatide, each confirmed from their own website, with telehealth options available. Tirzepatide requires a prescription from a licensed provider. Browse them at https://www.disclosedlabs.com/prescribers?peptide=Tirzepatide.

How does Tirzepatide work?

Tirzepatide is a 39-amino-acid synthetic peptide that co-activates the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. GLP-1R activation enhances glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and reduces appetite via central satiety pathways; GIP receptor agonism augments insulin secretion, improves adipose tissue lipid handling, and may blunt GLP-1-mediated nausea — producing greater A1C and weight-loss effects than selective GLP-1 agonists.

What does the research say about Tirzepatide?

The SURPASS program established efficacy in type 2 diabetes, including SURPASS-2 (Frias et al., NEJM 2021), in which tirzepatide was superior to semaglutide 1 mg for A1C reduction and body weight. The SURMOUNT-1 obesity trial (Jastreboff et al., NEJM 2022) demonstrated up to approximately 20.9% mean body-weight reduction at 15 mg over 72 weeks. SURMOUNT-OSA (Malhotra et al., NEJM 2024) showed large reductions in apnea-hypopnea index in obstructive sleep apnea with obesity, supporting the 2024 FDA indication (Zepbound for moderate-to-severe OSA in adults with obesity). The SUMMIT trial (Packer et al., NEJM 2025) demonstrated a lower risk of cardiovascular death or worsening heart failure in HFpEF with obesity.