Cetrorelix vs Ganirelix: evidence, status and structure
A side-by-side look at Cetrorelix and Ganirelix, using the data on each VALREXA profile. Neither comparison is a recommendation.
Key differences
- Both sit at the same evidence level: Approved use.
- Both have the same U.S. status category: FDA-approved.
| Cetrorelix | Ganirelix | |
| Research class | Endocrine & Growth | Endocrine & Growth |
| Human evidence | Approved use | Approved use |
| U.S. status | FDA-approved (Cetrotide) | FDA-approved (Antagon) |
| 2026 compounding decision | — | — |
| Amino acids | 10 (decapeptide, several D-residues) | 10 (decapeptide, several D-residues) |
| Molecular weight | ~1,431 Da | ~1,570 Da |
| Formula | C₇₀H₉₂ClN₁₇O₁₄ | C₈₀H₁₁₃ClN₁₈O₁₃ |
| Sequence | Ac-D-Nal-D-Cpa-D-Pal-Ser-Tyr-D-Cit-Leu-Arg-Pro-D-Ala-NH2 | Ac-D-Nal-D-Cpa-D-Pal-Ser-Tyr-D-Arg(Et)-Leu-His-Pro-D-Ala-NH2 |
| Research period | 2000 | 1999 |
| Safety summary | FDA-approved. Given by subcutaneous injection; watch for allergic reactions. | FDA-approved. Given by subcutaneous injection; mild injection-site reactions are common. |
How they differ
These are the two GnRH antagonist injections used in IVF to prevent the ovaries from releasing eggs early, and they are effectively interchangeable in practice. Both block the pituitary GnRH switch directly and work immediately, with no initial hormone flare. Cetrorelix can be given as a single 3 mg dose with several days of coverage or daily 0.25 mg; ganirelix is daily 250 mcg. Clinic choice is driven by protocol and pricing, not by meaningful clinical differences.
What each one is
Cetrorelix: A GnRH antagonist injection that prevents premature ovulation during fertility treatment. Molecular weight, sequence, research history, human evidence and regulatory status.
Ganirelix: A GnRH antagonist injection used in fertility treatment to prevent early ovulation. Molecular weight, sequence, research history, human evidence and regulatory status.
Educational reference only. Nothing here is medical advice, a treatment recommendation, or dosing or sourcing guidance. Report an error.