Norgestomet is a synthetic derivative of progesterone with improved oral activity due to its 17α-acetate side chain. In veterinary medicine norgestomet is used for the synchronisation of oestrus in cattle. It is administered as a subcutaneous ear implant (containing 3 mg norgestomet; to be removed after 9 to 10 days), in combination with a single intramuscular injection containing 3 mg norgestomet and 5 mg oestradiol valerate. The injection is to be given immediately after application of the implant. Norgestomet is not used in human medicine. It is a steroidal progestin of the 19-norprogesterone group.