What is Tirzepatide?
Tirzepatide is engineered on a GIP derived backbone rather than a GLP-1 backbone, with substitutions including non-standard residues that block dipeptidyl peptidase 4 cleavage, and a fatty diacid attached through a spacer for albumin binding. The molecular reference for this catalog lists CAS 2023788-19-2, the formula C225H348N48O68, and an average mass of 4813.45, with no residue sequence recorded, so none is reproduced here.
The interesting structural feature in the published literature is imbalance. Tirzepatide is reported to engage the GIP receptor with higher relative potency than the GLP-1 receptor, and at the GLP-1 receptor it shows a signalling profile that favours cyclic AMP accumulation over beta arrestin recruitment in the cell assays used. Rodent and cell model studies use it to probe how unequal engagement of two incretin receptors changes downstream readouts compared with an equipotent pairing (Willard, 2020).
What is unsettled is how much of the observed pharmacology in animal models is attributable to the GIP arm at all, since GIP receptor agonism and antagonism have both been reported to produce similar directional effects in some rodent studies.
Reconstitution & handling
Diluent is added slowly along the wall of the vial rather than onto the cake, then the vial is rolled gently until the solution clears, typically within a minute or two. Vortexing is avoided because it foams and shears long acylated peptides. Concentration is a division, labelled mass over diluent volume, so 2 mL into a 10 mg vial yields 5 mg per millilitre.
Storage & stability
Sealed lyophilized vials are stored at -20 °C, protected from light and moisture, and allowed to reach room temperature before opening so condensation does not contact the powder. Reconstituted material is refrigerated at 2 to 8 °C and aliquoted for single use. Repeated freezing and thawing is the dominant avoidable route to aggregation, and the acyl chain promotes adsorption onto untreated plastic.
How it's tested
Lots are analysed by reversed phase HPLC at 214 and 220 nm and reported at 99 percent or greater main peak area. Identity is confirmed by mass spectrometry against the theoretical average mass of 4813.45 calculated from C225H348N48O68, which also distinguishes the molecule from shorter deletion sequences arising in synthesis. Net peptide content is measured separately, and a lot-matched certificate is available on request.