Follicle-stimulating hormone (FSH; also follitropin) is a 33 kDa heterodimer belonging to the glycoprotein hormones subunit beta family . The heterodimer is composed of two glycoproteins linked noncovalently: a common alpha subunit, which is also a component of luteinizing hormone, thyroid stimulating hormone, and chorionic gonadotropin; and a unique beta subunit that confers the protein’s specific biological action and is responsible for the interaction with FSH-receptor.
