What it is

HMG is a mix of follicle-stimulating hormone (FSH) and luteinising hormone (LH), two large glycoprotein hormones made of an alpha and a beta chain with sugar chains attached. After menopause the pituitary pours out FSH and LH because the ovaries no longer answer, and the excess passes into urine, which is where HMG is collected and purified. A 75 IU vial carries 75 IU of each activity, in a 1 to 1 ratio. Because both hormones are present, it drives the testes or ovaries the way the pituitary does, without needing the brain's signal.