Human chorionic gonadotropin (hCG) has a half-life that is noticeably longer than other heterodimeric glycohormones, such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), and thyroid-stimulating hormone (TSH), according to earlier research. The primary cause is because the CTP found in the hCG β-subunit (HCG-β) has about 31 amino acid residues, forming four O-glycosylation sites that end in sialic acid residues. Monosaccharides with a negative charge are called sialic acids. Negatively charged polysaccharides will reject recombinant therapeutic peptides or proteins with negative surface charges.
For more: https://half-life-extensio...