Weight & Metabolic

Incretin and metabolic research peptides. This category covers compounds studied in glucose homeostasis, incretin receptor pharmacology and mitochondrial metabolism: Semaglutide and GLP-III, studied at GLP-1 and multi-incretin receptors; Tirzepatide, a dual GIP/GLP-1 receptor compound; and MOTS-c, a mitochondrial-derived peptide examined in metabolic regulation research.
Most of this category consists of engineered molecules rather than natural sequences, and they solve the same two problems in the same way. Native GLP-1 survives about two minutes in circulation: dipeptidyl peptidase-4 cleaves it, and the kidney filters whatever survives. Semaglutide and tirzepatide both place α-aminoisobutyric acid at the cleavage site to block the enzyme, and both carry a fatty diacid on a lysine side chain that binds serum albumin reversibly, shielding the peptide from renal clearance. MOTS-c is the outsider — a 16-residue peptide encoded not in the nucleus but within mitochondrial DNA.
These are the most demanding molecules in the catalogue to verify. A 31- to 39-residue chain with non-proteinogenic residues, a multi-step side-chain conjugation and, for tirzepatide, a C-terminal amide gives synthesis several places to go incompletely right. A purity figure without mass confirmation answers the wrong question here: HPLC quantifies how much of one species is present, but only mass spectrometry establishes that the acylation is present at all — an absent lipid side chain shifts the mass by several hundred daltons, and a free acid where an amide belongs shifts it by one. Our guide to purity verification covers what each method actually establishes.
These are research reagents, not medicines. None is approved for human or veterinary use, and none is intended for human or animal consumption. All batches carry independent HPLC and mass-spectrometry analysis, with Certificates of Analysis available on request.