Human chorionic gonadotrophin (hCG) is a glycoprotein hormone produced during pregnancy in humans. I was first discovered in 1920 and later sold under prescription to the market in 1932 as Pregnyl. At that time the hormone was extracted from animal pituitary glands. In the 1940’s new manufacturing techniques were developed that allowed for the hormone to be extracted from purified urine obtained from pregnant women. In the case of Pregnyl this is still done to this day. Recently new techniques of recombinant DNA modification allowed for a new synthetic product called Ovidrel. Other than the differences in manufacturing processes there are some notable differences in effects between Pregnyl and Ovidrel.