Human follicle stimulating hormone (FSH) is a glycoprotein hormone produced by the anterior pituitary gland. There are three other glycoprotein hormones, namely Thyroid Stimulating Hormone, Luteinizing Hormone (both produced by anterior pituitary gland) and Human Chorionic Gonadotropin (produced by the placenta) which are structurally similar. Each hormone has an alpha and beta subunit. The α subunits of each hormone are similar while the β subunit is specific to each hormone. The α subunits contain 92 amino acids while the β subunits vary with each hormone. The β subunit of both FSH and LH contain 115 amino acids, TSH 110 amino acids, and hCG 147 amino acids.