Peptide LibraryGanirelix
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.
For research use only.
Key Facts
- CAS
- —
- Molecular Weight (MW)
- 1570.3 g/mol
- Half-life
- —
- FDA status
- Approved
- Evidence level
- FDA Approved
- Human dose established
- Yes
- Administration Route
- Subcutaneous
- Frequency
- Once daily
- Last updated
- Nov 7, 2026
- Reviewed
- Nov 7, 2026
Research summary
Synthetic decapeptide GnRH receptor antagonist approved to prevent premature luteinising hormone surges in women undergoing controlled ovarian hyperstimulation.
Research evidence
- Regulatory review (FDA label)2 reviewed sources
- Controlled human trials1 reviewed source
- Early or uncontrolled human studiesNone in reviewed sources
- Lab & animal studiesNone in reviewed sources
How it works
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.
Peptide Library's Ganirelix profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Ganirelix dosage evidence
Ganirelix has an FDA-approved human dosage for preventing a premature LH surge in women having controlled ovarian hyperstimulation. The label dose is 250 mcg under the skin once a day from the mid to late follicular phase, after FSH has been started on day 2 or 3 of the cycle, continued until the day of hCG.
| Human dosing established | Yes |
|---|---|
| Studied dose range | 250 mcg once daily during ovarian stimulation, until the day of hCG |
| Route | Subcutaneous |
| Frequency | Once daily |
| Duration studied | From the mid to late follicular phase until the day of hCG |
| Evidence level | FDA Approved |
| Last reviewed | 2026-11-07 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| FDA label — Ganirelix Acetate Injection (Organon)FDA-approved label · FDA prescribing information | Women undergoing controlled ovarian hyperstimulation | 250 mcg | Subcutaneous (prefilled syringe) | Once daily | Mid to late follicular phase until the day of hCG administration | Inhibition of premature LH surges | Ganirelix Acetate Injection (Organon) — FDA prescribing information, DailyMed |
| FDA label — FYREMADEL (ganirelix acetate) injectionFDA-approved label · FDA prescribing information | Women undergoing controlled ovarian hyperstimulation | 250 mcg | Subcutaneous (prefilled syringe) | Once daily | Mid to late follicular phase until the day of hCG administration | Inhibition of premature LH surges | FYREMADEL (ganirelix acetate) injection — FDA prescribing information (Ferring), DailyMed |
| Ganirelix dose-finding trial (de Jong et al., 2001)Clinical trial · Randomised controlled multicentre dose-finding trial | Women having IVF with recombinant FSH (n=329) | 0.0625, 0.125, 0.25, 0.5, 1.0 or 2.0 mg a day | Not stated in the indexed abstract | Daily, from cycle day 7 | Not stated in the indexed abstract | Follicle growth was similar across doses; late follicular LH, androstenedione and estradiol fell as the dose rose | 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. |
Where sources disagree
- Ganirelix is one part of an IVF protocol. The labels pair it with FSH from day 2 or 3 and hCG to trigger final follicle maturation, and say hCG should be withheld if the ovaries are abnormally enlarged.
- Organon's product, the original ganirelix, is now labelled simply "Ganirelix Acetate Injection"; no DailyMed listing carries the older Antagon name. Several other companies list ganirelix with the same 250 mcg daily dose.
- The labels say pregnancy must be excluded before treatment and report hypersensitivity reactions, including anaphylactoid reactions.
Sequence & molecular data
| Molecular formula | C80H113ClN18O13 |
|---|---|
| Molecular weight | 1570.3 g/mol |
| PubChem CID | 16130957 |
| FDA UNII | IX503L9WN0 |
| ChEMBL | CHEMBL1251 |
| DrugBank | DB06785 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
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.
Studies
- Efficacy and safety of newly developed ganirelix acetate in infertile women for assisted reproductive technology: a prospective, randomised, controlled study
- GnRH Peptide Antagonist: Comparative Analysis of Chemistry and Formulation with Implications for Clinical Safety and Efficacy
- The effect of an individualized GnRH antagonist protocol on folliculogenesis in IVF/ICSI
- 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)
- The effects of GnRH antagonist on the endometrium of normally menstruating women
Research statistics
285 PubMed publications · 71.0% human clinical research · 67 registered trials
Counts of published research through 2026-11-01, not evidence that it works. Publications by year, study types and trials · How publications are counted
Regulatory & research 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 |
|---|---|
| Research status | Approved product (see FDA status) |
| Availability | Prescription-Only |
| WADA (sport) | Unknown / Not Listed |
| Library classification | FDA-Approved |
How FDA approval, compounding and research-only status differ
Benefits
—
Ganirelix side effects
No side effects listed yet for this entry.
Storage & stability
This compound is not supplied as a powder to be mixed, so the freeze-dried powder and reconstitution handling described for research peptides does not apply. Storage conditions are product-specific: follow the label or packaging of the product itself.
Ganirelix: 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, 2022External reference
- GnRH Peptide Antagonist: Comparative Analysis of Chemistry and Formulation with Implications for Clinical Safety and Efficacy — Pharmaceuticals (Basel), 2024External reference
- The effect of an individualized GnRH antagonist protocol on folliculogenesis in IVF/ICSI — Hum Reprod, 2004External reference
- 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, 2001External reference
- The effects of GnRH antagonist on the endometrium of normally menstruating women — J Assist Reprod Genet, 2007External reference
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Nov 7, 2026 · Version 2
This Ganirelix profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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