# Tirzepatide

> Evidence tier S — Approved · Metabolic · reviewed 2026-11-08
> Source page: https://peptidemeta.com/p/tirzepatide/

Also known as: LY3298176, Mounjaro, Zepbound

## Quick answers

**What is Tirzepatide?**

A dual GIP/GLP-1 receptor agonist FDA-approved for type 2 diabetes (Mounjaro) and obesity (Zepbound).

**How strong is the evidence for Tirzepatide?**

Tier S (approved) on the peptidemeta evidence scale. Phase 3 RCT programmes (SURPASS, SURMOUNT); FDA-approved in 2022 for type 2 diabetes (Mounjaro) and in 2023 for weight management (Zepbound).

**Is Tirzepatide FDA-approved?**

Yes. The FDA approved Tirzepatide (Mounjaro, Zepbound) in 2022. Approved for type 2 diabetes (Mounjaro, 2022) and chronic weight management (Zepbound, 2023).

**Is Tirzepatide banned in sport?**

No. Tirzepatide is not on the World Anti-Doping Agency Prohibited List.

**How does Tirzepatide work?**

Tirzepatide is a dual GIP/GLP-1 receptor agonist built on a 39-amino-acid peptide backbone with a C20 fatty diacid moiety enabling albumin binding and once-weekly dosing. It enhances glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and acts on hypothalamic appetite centers to reduce food intake.

**What is known about the safety of Tirzepatide?**

FDA-approved with extensive Phase III safety data (SURPASS and SURMOUNT programs). Most common side effects are GI-related: nausea, diarrhea, decreased appetite, vomiting, constipation.

## Key facts

- **Evidence tier:** S (Approved)
- **FDA:** approved 2022 (Mounjaro, Zepbound)
- **WADA:** not on the Prohibited List
- **Peptide:** yes
- **Sequence:** Y[Aib]EGTFTSDYSI[Aib]LDKIAQKAFVQWLIAGGPSSGAPPPS[NH2] (39 residues)
- **Formula:** C225H348N48O68
- **Molecular weight:** 4813.5 g/mol
- **Discovered:** 2018 — Discovery and first clinical data published by Eli Lilly as LY3298176 (Coskun et al., Mol Metab 2018).
- **Routes studied:** Subcutaneous

## Overview

A dual GIP/GLP-1 receptor agonist FDA-approved for type 2 diabetes (Mounjaro) and obesity (Zepbound). It delivers substantial weight loss and glycemic improvements in large-scale trials.

## Mechanism

Tirzepatide is a dual GIP/GLP-1 receptor agonist built on a 39-amino-acid peptide backbone with a C20 fatty diacid moiety enabling albumin binding and once-weekly dosing. It enhances glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and acts on hypothalamic appetite centers to reduce food intake.

## Effects reported in research

_Reported outcomes, not promises; see the evidence tier._

- Substantial sustained weight loss
- Improved insulin sensitivity
- Reduced HbA1c levels
- Decreased cardiovascular risk markers

## Safety & unknowns

FDA-approved with extensive Phase III safety data (SURPASS and SURMOUNT programs). Most common side effects are GI-related: nausea, diarrhea, decreased appetite, vomiting, constipation. Boxed warning for thyroid C-cell tumors (preclinical rodent signal). Contraindicated in personal/family history of medullary thyroid carcinoma or MEN 2.

## Studies

- Jastreboff AM, Aronne LJ, Ahmad NN, et al. (2022). *Tirzepatide Once Weekly for the Treatment of Obesity*. New England Journal of Medicine. Clinical trial. https://pubmed.ncbi.nlm.nih.gov/35658024/
  In the 72-week phase 3 SURMOUNT-1 RCT in 2539 adults with obesity, mean weight change was -15.0%, -19.5%, and -20.9% with 5, 10, and 15 mg versus -3.1% with placebo.
- Frías JP, Davies MJ, Rosenstock J, et al. (2021). *Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes*. New England Journal of Medicine. Clinical trial. https://pubmed.ncbi.nlm.nih.gov/34170647/
  In the 40-week SURPASS-2 RCT, all three tirzepatide doses lowered HbA1c more than semaglutide 1 mg (differences -0.15 to -0.45 percentage points).
- Rosenstock J, Wysham C, Frías JP, et al. (2021). *Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1): a double-blind, randomised, phase 3 trial*. The Lancet. Clinical trial. https://pubmed.ncbi.nlm.nih.gov/34186022/
  In the 40-week SURPASS-1 RCT in 478 adults with type 2 diabetes, tirzepatide monotherapy at all doses was superior to placebo for change in HbA1c.

## Status sources

- [Drugs@FDA — Mounjaro (NDA 215866)](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=215866)
- [Drugs@FDA — Zepbound (NDA 217806)](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=217806)
- [KEGG DRUG D11360 — tirzepatide (sequence, formula, MW)](https://www.kegg.jp/entry/D11360)
- [Jastreboff et al., NEJM 2022 (SURMOUNT-1 RCT)](https://pubmed.ncbi.nlm.nih.gov/35658024/)
- [Coskun et al., Mol Metab 2018 (discovery)](https://pubmed.ncbi.nlm.nih.gov/30473097/)

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Educational reference only — not medical advice. No dosing information is published. Tiers rate the strength of published evidence, not effectiveness or safety.