The antagonist protocol is a commonly used IVF stimulation protocol in which a GnRH antagonist medicine is introduced partway through stimulation to prevent a premature LH surge and early ovulation, allowing egg retrieval to be timed appropriately. It generally involves a shorter overall treatment duration compared with some other protocols and is widely used in current practice, including for women considered at higher risk of OHSS, because it allows an alternative trigger option that can reduce that risk. The suitability of the antagonist protocol for a given individual is judged by the treating fertility specialist based on ovarian reserve, prior response and overall health. This entry does not describe medicine names or doses.
Also known as: GnRH antagonist protocol
Related India guides
Sources
- ICMR Standard Treatment Workflows (icmr.gov.in/standard-treatment-workflows-stws)
Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.