Tirzepatide

What Is Tirzepatide?

Tirzepatide (CAS 2023788-19-2; also known as LY3298176) is a 39-amino acid synthetic peptide engineered as a dual agonist of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. Structurally it carries a C-20 fatty diacid conjugated via a γGlu-2xOEG linker to Lys20, which mediates albumin binding and extends the plasma half-life to approximately 5 days. CertaPeptides supplies tirzepatide in lyophilized powder form from 500mcg through 100mg per vial.

CAS: 2023788-19-2. Alternate identifier: LY3298176. Molecular weight: 4813.5 g/mol. Receptor-engagement profile: GIP-R and GLP-1R with imbalanced pharmacology favouring GIP-R.

What Published Clinical Research Has Reported

The trial figures below are direct attributions to peer-reviewed clinical trial publications. They describe outcomes measured in specific trial populations under specific protocols, and are reported here for research context only. They are not claims about what CertaPeptides' research compound will do in any individual.

Type 2 diabetes — SURPASS-1 trial (Rosenstock et al., 2021)

Rosenstock et al. (2021) reported, in the SURPASS-1 double-blind placebo-controlled trial of 478 adults with type 2 diabetes inadequately controlled by diet and exercise, a mean change in HbA1c from baseline to week 40 of −1.87 percentage points in the tirzepatide 5 mg group, −1.89 in the 10 mg group, and −2.07 in the 15 mg group, versus +0.04 in placebo. Mean body-weight change was −7.0 kg, −7.8 kg, and −9.5 kg respectively, versus −0.7 kg in placebo. Source: The Lancet, 2021;398(10295):143–155. PMID 34186022.

Head-to-head versus semaglutide — SURPASS-2 trial (Frias et al., 2021)

Frias et al. (2021) reported, in the SURPASS-2 open-label active-comparator trial of 1,879 adults with type 2 diabetes randomised to tirzepatide 5/10/15 mg or semaglutide 1 mg once-weekly over 40 weeks, a mean change in HbA1c of −2.01, −2.24, and −2.30 percentage points in the tirzepatide groups versus −1.86 in the semaglutide group. Mean body-weight change was −7.6 kg, −9.3 kg, and −11.2 kg in the tirzepatide groups versus −5.7 kg in semaglutide. Source: New England Journal of Medicine, 2021;385(6):503–515. PMID 34170647.

Obesity — SURMOUNT-1 trial (Jastreboff et al., 2022)

Jastreboff et al. (2022) reported, in the SURMOUNT-1 Phase 3 trial of 2,539 adults with obesity (BMI ≥30, or ≥27 with comorbidities) and without diabetes, a mean percent change in body weight from baseline to week 72 of −15.0% in the tirzepatide 5 mg group, −19.5% in the 10 mg group, −20.9% in the 15 mg group, versus −3.1% in placebo. Source: New England Journal of Medicine, 2022;387(3):205–216. PMID 35658024.

Within the Incretin Class — How Tirzepatide Differs

Tirzepatide is studied alongside two other research peptides in the same metabolic class: semaglutide (single GLP-1R agonist) and retatrutide (triple GIP/GLP-1/GCG agonist). The three differ structurally and mechanistically in ways that shape how each compound is studied:

Tirzepatide's distinguishing feature is the imbalanced dual agonism: it binds GIP-R with native-GIP-like affinity while showing biased agonism at GLP-1R. Preclinical research attributes roughly 30% of its total insulin-sensitisation effect to the GIP-R arm, mediated through enhanced glucose disposal in white adipose tissue. This is the mechanistic basis for SURPASS-2 outcomes where tirzepatide surpassed semaglutide on both glycaemic and weight endpoints. Researchers comparing the three frequently reference the tirzepatide dual-agonist mechanism overview and the GLP-1 class comparison overview.

Research Areas Where Tirzepatide Is Studied

• Dual-incretin receptor pharmacology and comparative binding assays
• Biased agonism at GLP-1R (cAMP vs β-arrestin pathway recruitment)
• Adipose-tissue glucose disposal mediated by GIP-R engagement
• Head-to-head comparisons against semaglutide and retatrutide
• Long-acting peptide formulation and stability research

Specifications

Storage

Lyophilized powder: −20°C for long-term storage. 2–8°C for short-term use before reconstitution.

Reconstituted: 2–8°C, use within 4 weeks. Do not freeze after reconstitution.

Quality Assurance

• HPLC analysis confirms 99.3% avg purity on every batch
• Mass spectrometry verifies molecular identity
• Certificate of Analysis (COA) included with every order — view sample COAs
• EU-based quality control under CERTALAB S.R.L.

Important Notice — Research Use Only

Tirzepatide is supplied by CertaPeptides strictly as a laboratory research compound. The clinical-trial figures cited above are taken from peer-reviewed human clinical trials (SURPASS-1, SURPASS-2, SURMOUNT-1) published in NEJM and The Lancet, and are reported here for research context only. They are not medical claims and do not describe what CertaPeptides' research material will do in any individual. This product is not a drug, not a dietary supplement, not a cosmetic, and not approved by the FDA, EMA, or any other regulatory authority for over-the-counter sale for human or veterinary use. It is not intended to diagnose, treat, cure, prevent, or mitigate any disease or condition. For laboratory research purposes only. Not for human consumption.