hCG (human chorionic gonadotropin)

hCG is produced by the developing placenta and is what urine and blood pregnancy tests detect. Because it acts on the same receptor as LH, an hCG injection is also used to mature eggs before egg collection or to time ovulation in IUI cycles. This is why a pregnancy test taken too soon after a trigger injection can be positive from the medicine rather than a pregnancy.

Also known as: beta hCG, pregnancy hormone, HCG, human chorionic gonadotrophin

Last reviewed: 8 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.