Overview
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In plain language
Tirzepatide is an FDA-approved weekly injection sold as Mounjaro for type 2 diabetes and Zepbound for weight management and sleep apnea. It acts on two hormone receptors, GIP and GLP-1, so it is called a "dual agonist."
Both hormones are released by the gut after eating and help control blood sugar and appetite. In trials, tirzepatide produced more weight loss on average than semaglutide. The most common side effects are nausea and other stomach upset.
For students
Tirzepatide (about 4,814 Da) is a 39-residue peptide built mostly on the GIP sequence, with a C20 fatty diacid on Lys20 for albumin binding and a half-life of about five days. It activates the GIP receptor fully and the GLP-1 receptor more weakly, a profile described as "imbalanced" in favor of GIP.
At the GLP-1 receptor, it is biased toward cAMP signaling over beta-arrestin recruitment, which may reduce receptor internalization.
For researchers and instructors
Clinical evidence. SURPASS trials in type 2 diabetes showed larger HbA1c reductions than comparators. In SURMOUNT-1, the highest dose produced mean weight loss of about 21% at 72 weeks. SURMOUNT-5 showed greater weight loss than semaglutide. SURMOUNT-OSA supported approval for obstructive sleep apnea with obesity.
Safety. Gastrointestinal effects, gallbladder events, pancreatitis warnings and a boxed warning for thyroid C-cell tumors seen in rodents.
Status. FDA-approved (Mounjaro, Zepbound).
Molecular identity
- Amino acids
- 39 (modified)
- Molecular weight
- ~4,813.5 Da
- Formula
- C₂₂₅H₃₄₈N₄₈O₆₈
- Sequence
- Modified 39-residue GIP-based peptide with a C20 fatty diacid chain
Origin and history
Tirzepatide combines two gut hormones. The first, GIP, was discovered in 1970 by John Brown in Vancouver, who named it “gastric inhibitory polypeptide”; it was later renamed glucose-dependent insulinotropic polypeptide when its insulin effect turned out to matter more.
Eli Lilly designed tirzepatide as a single 39-amino-acid molecule built mostly on GIP’s sequence that also activates the GLP-1 receptor, with a fatty-acid chain for once-weekly dosing. The 2022 SURMOUNT-1 trial reported about 21% average weight loss at the highest dose. It was approved as Mounjaro in 2022, as Zepbound in 2023 and for obstructive sleep apnea in 2024.
Key people
- John C. BrownDiscovered GIP (1970)
- Eli LillyDeveloped tirzepatide
Timeline
- 1970
GIP discovered
- 2018
Tirzepatide first described
- 2022
FDA approves Mounjaro; SURMOUNT-1 results
- 2023
Zepbound approved for weight management
- 2024
Approved for obstructive sleep apnea
See every peptide on one history timeline.
Human evidence
Supported by the randomized SURPASS and SURMOUNT trial programs. Zepbound is also approved for moderate-to-severe obstructive sleep apnea in adults with obesity.
Registration and enrollment are not proof of benefit; check study results directly.
Explore original publications and distinguish preclinical findings from controlled human evidence.
Safety and regulatory status
See every compound on the regulatory tracker.
FDA-approved as Mounjaro and Zepbound. Common side effects are gastrointestinal; labels include a boxed warning about thyroid C-cell tumors seen in rodents.
This profile is educational and does not provide treatment, dosing or sourcing guidance.
Sources
- PubMed literature search: Tirzepatide
- PubChem compound search: Tirzepatide
- DailyMed (FDA label search): Tirzepatide
- PubMed: SURMOUNT-1
- ClinicalTrials.gov search: Tirzepatide
Hernandez Gener, E. (2026, November 7). Tirzepatide: molecular data, research history and evidence. VALREXA Biosciences. https://valrexa.com/peptides/tirzepatide.html
APA style · Last reviewed November 7, 2026 · Our editorial standardsLast reviewed November 7, 2026. Trial and regulatory status can change; confirm in the linked registries. This profile is educational and is not medical advice, a treatment recommendation, or dosing or sourcing guidance. Report an error · Corrections policy