Glycoprotein hormones (FSH, LH, gonadotropin and TSH) area unit a family of heterodimeric proteins composed of 2 noncovalently joined subunits; α and β. Glycoproteins area unit used clinically within the treatment of the many diseases. One major issue concerning the clinical use of the many peptides is their short half-life thanks to the speedy clearance from the circulation. to beat this downside, we have a tendency to succeeded to ligate the signal sequence of O-linked oligosaccharides to the committal to writing sequence of the hormones. The container cistron that has been used contains the sequence of the carboxyl-terminal amide (CTP) of human sac hormone β (hCGβ) monetary unit. The CTP contains twenty eight amino acids with four O-linked carbohydrate recognition sites. it absolutely was postulated that O-linked oligosaccharides add flexibility, hydrophilicity and stability to the supermolecule. On the opposite hand, it absolutely was steered that the four Olinked oligosaccharides play a crucial role in preventing plasma clearance and so increasing the half-life of the supermolecule in circulation. mistreatment this strategy, we have a tendency to succeeded to ligate the CTP to the committal to writing sequence of follitropin (FSH), endocrine (TSH), glycoprotein (EPO) endocrine (GH) and so to extend the longevity and bioactivity of those proteins in-vivo. curiously, the new analogs of FSH and GH were found to be not immunogenic in human and it's already passed with success clinical trials clinical trial and phase II clinical trial, severally.