--- title: "Ganirelix" canonical_url: https://peptidelibrary.app/library/ganirelix description: "Synthetic decapeptide GnRH receptor antagonist approved to prevent premature luteinising hormone surges in women undergoing controlled ovarian hyperstimulation." updated: 2026-11-07 publisher: Peptide Library notice: "Research and educational use only. Not medical advice." --- # Ganirelix Ganirelix is an FDA-approved GnRH receptor antagonist. Ganirelix is a GnRH decapeptide analog with substitutions at positions 1, 2, 3, 6, 8 and 10 that confer competitive antagonism at the pituitary GnRH receptor. Binding induces rapid, reversible suppression of gonadotropin secretion, with luteinising hormone falling more than follicle-stimulating hormone. Synthetic decapeptide GnRH receptor antagonist approved to prevent premature luteinising hormone surges in women undergoing controlled ovarian hyperstimulation. ## Classification - Type: FDA-approved GnRH receptor antagonist - Mechanism class: GnRH Modulator - Development stage: Approved product - Regulatory class: FDA-approved medicine ## Mechanism Ganirelix is a GnRH decapeptide analog with substitutions at positions 1, 2, 3, 6, 8 and 10 that confer competitive antagonism at the pituitary GnRH receptor. Binding induces rapid, reversible suppression of gonadotropin secretion, with luteinising hormone falling more than follicle-stimulating hormone. Its effect is dose-dependent and gonadotropin secretion recovers promptly after the last dose. ## Properties - Molecular formula: C80H113ClN18O13 - Molecular weight: 1,570.3 g/mol - Studied routes: Subcutaneous ## Evidence - Evidence level: FDA Approved - Highest documented: Regulatory review (FDA label) - Human trials: 1 - Controlled human trials: 1 - Preclinical sources: 0 - Latest source: 2001 Each step shows whether the sources Peptide Library has reviewed include that kind of research. Counts are reviewed sources, not every study ever published. Reviews and programme summaries that describe human use are shown as "reported", not as trials, and registered trials without published results are listed but not counted. A higher step means research has progressed further; it does not mean a compound works better or is safer. Compounds whose evidence has not been reviewed yet show "Not reviewed" instead of a guess. ### Studies 1. Ganirelix Acetate Injection (Organon) — FDA prescribing information, DailyMed. Regulatory label (FDA), human. Population: Women undergoing controlled ovarian hyperstimulation. Inhibition of premature LH surges [Source](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=32fb74ff-993a-49fe-8943-e029372b863e) 2. FYREMADEL (ganirelix acetate) injection — FDA prescribing information (Ferring), DailyMed. Regulatory label (FDA), human. Population: Women undergoing controlled ovarian hyperstimulation. Inhibition of premature LH surges [Source](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5f0908b5-3551-47fd-95f7-3669b0dff7f1) 3. de Jong D et al. Dynamics of the development of multiple follicles during ovarian stimulation for in vitro fertilization using recombinant follicle-stimulating hormone (Puregon) and various doses of the gonadotropin-releasing hormone antagonist ganirelix (Orgalutran/Antagon). Fertil Steril. 2001. 2001. Controlled human trial. Population: Women having IVF with recombinant FSH (n=329). Follicle growth was similar across doses; late follicular LH, androstenedione and estradiol fell as the dose rose [Source](https://pubmed.ncbi.nlm.nih.gov/11287020/) ## Safety Human safety basis: FDA prescribing information ## Regulatory status Ganirelix is an FDA-approved product for specific labelled indications. Approval does not extend to the research contexts described on this page, and approved products are prescription medicines. - FDA status: Approved - Availability: Prescription-Only ## Frequently asked questions ### What is Ganirelix? Synthetic decapeptide GnRH receptor antagonist approved to prevent premature luteinising hormone surges in women undergoing controlled ovarian hyperstimulation. ### How does Ganirelix work? Ganirelix is a GnRH decapeptide analog with substitutions at positions 1, 2, 3, 6, 8 and 10 that confer competitive antagonism at the pituitary GnRH receptor. Binding induces rapid, reversible suppression of gonadotropin secretion, with luteinising hormone falling more than follicle-stimulating hormone. ### Is Ganirelix FDA approved? Yes. Ganirelix is approved by the FDA, and approved products are prescription medicines. Approval is always for specific indications studied in clinical trials, so an approved status does not mean the compound is approved for every use it is discussed for. Research-chemical material sold under the same name is not the approved product. ### What peptides are similar to Ganirelix? Compounds most often compared with Ganirelix include Degarelix, Cetrorelix, Leuprolide and Gonadorelin. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ. ## References - [Efficacy and safety of newly developed ganirelix acetate in infertile women for assisted reproductive technology: a prospective, randomised, controlled study — J Obstet Gynaecol, 2022](https://pubmed.ncbi.nlm.nih.gov/35254199/) - [GnRH Peptide Antagonist: Comparative Analysis of Chemistry and Formulation with Implications for Clinical Safety and Efficacy — Pharmaceuticals (Basel), 2024](https://pubmed.ncbi.nlm.nih.gov/39861098/) - [The effect of an individualized GnRH antagonist protocol on folliculogenesis in IVF/ICSI — Hum Reprod, 2004](https://pubmed.ncbi.nlm.nih.gov/15229205/) - [Dynamics of the development of multiple follicles during ovarian stimulation for in vitro fertilization using recombinant follicle-stimulating hormone (Puregon) and various doses of the gonadotropin-releasing hormone antagonist ganirelix (Orgalutran/Antagon) — Fertil Steril, 2001](https://pubmed.ncbi.nlm.nih.gov/11287020/) - [The effects of GnRH antagonist on the endometrium of normally menstruating women — J Assist Reprod Genet, 2007](https://pubmed.ncbi.nlm.nih.gov/18049889/)