A gonadotropin-releasing hormone (GnRH) agonist is a medicine used in some IVF stimulation protocols to control the timing of ovulation. It works on the pituitary gland, initially causing a brief release of hormones followed by suppression of the body's own LH surge, which helps the clinic control when eggs mature and prevents premature ovulation before egg retrieval. GnRH agonists are used in specific protocols (such as the 'long protocol') chosen by the fertility team based on individual factors including ovarian reserve and prior treatment response. They may also be used, in some circumstances, as an alternative to hCG for triggering final egg maturation, particularly in women at higher risk of OHSS. All aspects of timing and protocol selection are managed by the treating clinic. These medicines are prescription-only in India under CDSCO regulation and should be used only as directed by a fertility specialist.
Also known as: GnRH agonist protocol, long protocol injection
Related India guides
Sources
- ICMR Standard Treatment Workflows (icmr.gov.in/standard-treatment-workflows-stws)
- Central Drugs Standard Control Organisation (cdsco.gov.in)
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.