Injectable peptide used in in vitro fertilization to prevent a woman from ovulating prematurely during ovarian stimulation.
Regulatory status
Approved (FDA / EMA)
Family
GnRH antagonist
Scientific evidence
High
Number of findings
1
Where it acts
Sexual and reproductive · Hormones and metabolism
Also known as
cetrorelix, Cetrotide
Regulatory status
FDA (US): Approved (2000, Cetrotide) to inhibit the premature LH surge in women undergoing controlled ovarian stimulation
EMA (EU): Approved (1999, Cetrotide) to prevent premature ovulation in controlled ovarian stimulation
Dose
0.25 mg subcutaneously once a day from day 5–6 of stimulation until the day of ovulation induction (EMA label, Cetrotide).
Safety
Mild injection-site reactions; ovarian hyperstimulation syndrome (a risk inherent to stimulation); rare allergic reactions. Contraindicated in pregnancy and breastfeeding. Only in fertility treatments under medical supervision.
Differences between women and men
Indication exclusively for women in assisted reproduction treatments. Contraindicated in pregnancy and breastfeeding.
Effect by goal · level of evidence
IVF: less ovarian hyperstimulation than agonists
reducesHighmeta-analysis (AAA)in people
−57% hyperstimulation
In a Cochrane review of 45 trials (7,511 women), GnRH antagonist protocols (cetrorelix or ganirelix) reduced ovarian hyperstimulation syndrome (OR 0.43) with no clear differences in live births versus the long agonist protocol.
It blocks the GnRH receptor in the pituitary immediately. This slows the release of LH and FSH and prevents the LH surge that would trigger ovulation before the eggs are retrieved. Unlike agonists, it does not cause an initial 'surge'.
What the evidence says
In people
IVF: less ovarian hyperstimulation than agonists. In a Cochrane review of 45 trials (7,511 women), protocols with a GnRH antagonist (cetrorelix or ganirelix) reduced ovarian hyperstimulation syndrome (OR 0.43) with no clear differences in live births versus the long agonist protocol. PubMed 21563131