What is TIRZEPATIDE?
Tirzepatide is a synthetic single-chain polypeptide belonging to the class of incretin-mimetic peptides, and is classified within the GLP-1 category of research compounds as a dual GIP/GLP-1 receptor agonist. It is catalogued under CAS number 2023788-19-2 and carries the molecular formula C225H348N48O68 with an average molecular weight of 4813.45 g/mol. As a structurally engineered analog, it is investigated in in-vitro incretin-receptor pharmacology and metabolic-signaling research models.
Structurally, tirzepatide is a 39-residue peptide (39 amino acids) built on a modified incretin backbone. The sequence incorporates the non-proteinogenic residue 2-aminoisobutyric acid (Aib) at position 2 and in the position-13 region, substitutions that increase conformational rigidity and confer resistance to enzymatic degradation relative to native incretins. The lysine at position 20 is covalently conjugated to a C20 fatty-diacid moiety through a linker composed of a γ-glutamate spacer and two AEEA (8-amino-3,6-dioxaoctanoic acid) units, and the chain terminates in a C-terminal amide. The complete, position-by-position residue sequence is provided on the accompanying certificate of analysis.
This lipidation architecture is a defining feature of the molecule and is the subject of structure-activity study, as the fatty-acid tail is understood in research settings to mediate reversible association with serum albumin, extending the peptide's circulating profile in experimental systems. Within a strictly research context, tirzepatide is used as a reference agonist for probing GIP and GLP-1 receptor binding, receptor-complex conformation, and downstream cyclic-AMP signaling in cell-based assays. This product is offered for laboratory research use only and is not a drug, food, or cosmetic; it is not intended for diagnostic, therapeutic, or human or veterinary use.
Reconstitution & handling
Tirzepatide is supplied as a lyophilized (freeze-dried) powder and requires reconstitution in a suitable aqueous solvent before use in laboratory work. Bacteriostatic water (water containing 0.9% benzyl alcohol) and sterile water are the solvents most commonly selected for dissolving lipidated peptides of this class; sterile phosphate-buffered solutions may also be used depending on assay requirements. The lyophilate should be brought to room temperature before opening to minimize condensation, and the solvent should be introduced slowly by directing it against the inner wall of the vial rather than dispensing it directly onto the powder. The vial is then left undisturbed to allow the peptide to dissolve, with gentle swirling if needed; vigorous shaking or vortexing is avoided because mechanical shear and foaming can promote aggregation of an amphipathic, fatty-acid-conjugated peptide.
The C20 diacid modification gives tirzepatide surfactant-like, amphipathic character, so complete dissolution can be slower than for unmodified peptides and is favored by near-neutral to mildly basic conditions. A properly reconstituted solution should appear clear and free of visible particulates or persistent turbidity. Reconstitution and any subsequent handling or aliquoting should be performed under clean or aseptic technique to preserve sample integrity for analytical work.
Storage & stability
In its lyophilized form, tirzepatide is stable for extended periods when stored sealed, protected from light and moisture, and kept frozen; short intervals at refrigerated or ambient temperature during shipping and handling are generally tolerated by the dry powder. Once reconstituted, the peptide is far less stable and should be maintained refrigerated at approximately 2-8 °C for near-term use, with light exposure minimized. For longer retention of reconstituted material, storage frozen in single-use aliquots is preferred so that repeated freeze-thaw cycles — a primary driver of peptide degradation and aggregation — can be avoided. Handling material at cold temperatures and limiting time at room temperature helps preserve chromatographic purity over the working period.
How it's tested
Each lot of tirzepatide is characterized analytically and released with a certificate of analysis (COA) documenting its identity and purity. Chromatographic purity is determined by reversed-phase high-performance liquid chromatography (RP-HPLC), which resolves the target peptide from process-related impurities and truncated or deletion sequences and supports the stated specification of ≥99% purity. Identity and molecular integrity are confirmed by mass spectrometry (typically ESI-MS or MALDI-TOF), with the measured mass compared against the theoretical molecular weight of 4813.45 derived from the C225H348N48O68 formula to verify the intact, correctly conjugated 39-residue structure. The COA consolidates these results — HPLC purity trace, mass-spectrometric identity, and lot-specific data — and is available for each batch as the analytical record of record.