Tirzepatide

Description

Tirzepatide is a single peptide that agonizes two receptors. Dual-receptor peptide design has been a research goal for years; tirzepatide is the compound that made it work at scale. Thirty-nine residues, a C20 fatty diacid linker, roughly five-day plasma half-life. The interesting question is not what it does but how the dual-receptor affinity ratio was engineered.

Proposed Mechanism

Both receptors — GIP and GLP-1 — are class B GPCRs that signal through Gs-adenylyl cyclase-PKA. Tirzepatide binds them at different affinities: GIP receptor affinity approaches native GIP, while GLP-1 receptor affinity is roughly five-fold lower than native GLP-1. That asymmetry is deliberate. The design choices behind it are laid out in Coskun et al. (2018, Molecular Metabolism), which is where most mechanism reviews start. The C20 linker handles half-life; the sequence engineering handles selectivity.

Research Literature

Coskun et al. (2018) is the discovery paper. Willard et al. (2020) characterized the differential receptor affinities in more structural detail. Frias et al. (2021, NEJM) examined dose-response pharmacology. Min and Bain (2021) reviewed the dual-agonist pharmacology at the class level. El et al. (2023, Peptides) is worth reading alongside Willard — it compares tirzepatide and semaglutide mechanistically and covers differential receptor residence times, which matter more than the raw binding numbers suggest.

Further reading: PubMed references for this compound.

Research Applications

Used in dual-receptor GPCR agonist pharmacology research, GIP vs GLP-1 receptor selectivity studies, and incretin-co-agonist design research. A reference compound in the emerging multi-agonist peptide class.

Supplied strictly for laboratory research use. Not for human or veterinary use.

Reconstitution

Supplied as a lyophilized powder. Reconstitute with bacteriostatic water prior to use. Use the Peptigo reconstitution calculator for guidance on volume and concentration.

Storage

• Unopened: room temperature up to 30 days during transit; refrigerate at 2-8°C long-term.
• Reconstituted: refrigerate at 2-8°C; stable 4-6 weeks. Protect from light.

Quality Verification

Every batch is independently tested by Janoshik Analytical. Certificates of Analysis include HPLC-UV purity, LC-MS identity confirmation, LAL bacterial endotoxin quantification, and USP <71> sterility testing.

Not a drug, supplement, or cosmetic. For in vitro research use only. Not for human consumption.

Frequently Asked Questions

Is this product legal to purchase in Canada for research use?

Peptigo supplies all products strictly for laboratory and in vitro research use. The compound is not a drug, supplement, or cosmetic, and is not sold for human or veterinary use. Researchers purchasing for their own laboratory work, university research programs, or independent in vitro protocols are the intended customer base. Health Canada’s April 2026 advisory specifically addresses unauthorized injectable peptide use; the research-use framing of this product is independent of that consumer-use category.

How is purity verified, and where can I see the Certificate of Analysis?

Every batch is tested independently by Janoshik Analytical, an accredited third-party laboratory. The standard testing panel includes HPLC-UV purity verification, LC-MS identity confirmation, LAL bacterial endotoxin quantification, and USP sterility testing. The Certificate of Analysis for each batch is available on the product page after purchase, and the testing methodology is detailed on the Lab Testing reference page.

What is the standard reconstitution and storage protocol for laboratory use?

The compound is supplied as a lyophilized powder. The standard diluent for reconstitution in research protocols is bacteriostatic water (0.9% benzyl alcohol). The Peptigo reconstitution calculator handles the volume-and-concentration arithmetic for a given target research dose. Unopened lyophilized peptide is stable at room temperature for up to 30 days during transit and should be refrigerated at 2-8°C for long-term storage. Reconstituted peptide should be refrigerated at 2-8°C and is typically functional for 4-6 weeks; protect from light.