Cetrorelix dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Cetrorelix is an FDA-approved drug used in fertility treatment to stop ovulation from happening too early.
Evidence grade for Cetrorelix: Moderate. The rule: at least one finished study in people, and at least 100 people who took it. The sum on this page: 1 completed trial, 564 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 564
- Human studies
- 1
- Found nothing
- 0
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
FDA-approved (Cetrotide)
3 effects reported, 1 unwanted, 2 wanted, by people using it, not a trial
Goal pages: Hormones and growth hormone
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Cetrorelix is a shot used in IVF. It blocks the brain signal that triggers ovulation, so eggs are not released too early. It works right away, with no first burst. It is sold as Cetrotide. It is approved and prescription only.
What people take it for
- Stopping early ovulation during IVF.
- A shorter IVF cycle with fewer shots.
- Lower risk of the ovaries overreacting.
What studies in people showed
The biggest source is a review that pooled 73 studies. This kind of drug cut the risk of the ovaries overreacting, without lowering live births. In 564 women aged 40 and over, though, the older long plan gave more eggs and more pregnancies than a plan with this drug. In a European study, it stopped the early hormone surge, with a rise in just 1.6 percent of women. It needed fewer days of shots and less fertility hormone than the older drug, buserelin.
What people report
Reports, not study results
The good
- Fewer days of shots and less fertility hormone per cycle.
- Lower risk of the ovaries overreacting, in the pooled studies.
The bad
- In women 40 and over, it gave fewer eggs and fewer pregnancies than the older plan.
- We have not collected user reports on this one yet.
Where these come from: Everything here is from the review and human studies on this page. We have not collected forum or user reports for this one yet.
My bottom line
This is fertility clinic medicine. Your age changes which plan works best, so that is a talk with your fertility doctor.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Cetrorelix has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Testosterone and male hormonesno headcount stated · 1 study
35 of the 36 indexed goals have no study of any kind behind Cetrorelix
No study in people, animals or cells on this page reports a result for these. That does not prove Cetrorelix does nothing for them. It does mean anything you have heard about Cetrorelix and one of these did not come from a study cited here.
Show full evidence
What is Cetrorelix?
Cetrorelix is an FDA-approved drug used in fertility treatment to stop ovulation from happening too early.
Cetrorelix blocks the GnRH switch directly. So it lowers LH and FSH right away, without the first burst seen with drugs like leuprolide and goserelin. That makes it handy in fertility treatment. It is FDA-approved as Cetrotide to stop ovulation from happening too early while the ovaries are being stimulated. A Cochrane review of 73 studies found this kind of drug cuts the risk of ovarian overstimulation a lot, without lowering live births. In 564 women aged 40 and over, the older long plan produced more eggs and more pregnancies than a cetrorelix plan. In a European study, cetrorelix stopped the early hormone surge, with a rise in only 1.6% of women. It needed fewer vials of fertility hormone and fewer days of shots than the older drug, buserelin.
How does Cetrorelix work?
It blocks GnRH receptors. That stops LH and FSH release right away.
The evidence, in charts
Fig. 1a · how many people
564people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| Fertility and Sterility 2009 | 564 | 100% |
The whole total is one study of 564. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 1 more study in people gives no headcount and is not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
2 of 3 sources here are studies in people. The rest is not.
- Study in people · done in people267%
- Review of studies · sums up other studies133%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 3 different years, 2000 to 2016, counted from the list of sources on this page. The newest source on file is from 2016, more than five years ago. Research on it may have gone quiet.
Fig. 3 · legal status at a glance
US
Approved
UK
Approved
AU
Approved
CA
Approved
Approved in all four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 5 · what the molecule is
- Kind of compound
- Peptide
- Molecule weight
- 1,431.1 Da
- Half-life
- About 34 hoursLong, 1 to 7 days
- Chain length
- None on file
Half-life as stated on file: ~5-63 hours (formulation dependent)
No amino acid sequence is on file for Cetrorelix, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2000Ovarian stimulation with HMG: results of a prospective randomized phase III European study comparing the LHRH-antagonist cetrorelix and the LHRH-agonist buserelin
In fertility treatment the newer drug did the same job with less of everything. Women having their ovaries stimulated were split by chance between cetrorelix and the older drug, buserelin. Cetrorelix stopped the early hormone surge that ruins an egg collection cycle, with a surge in only 1.6 of every hundred women. They needed fewer days of injections and less of the stimulating hormone. Fewer days and fewer vials is a shorter, cheaper cycle. The trial measured the cycle, not how many babies were born.
Cetrorelix prevented premature LH surges (1.6% LH rise) with fewer gonadotropin ampoules and stimulation days than buserelin.
- Study in people2009Cetrorelix protocol versus gonadotropin-releasing hormone analog suppression long protocol for superovulation in intracytoplasmic sperm injection patients older than 40
In women over 40, the older protocol beat the antagonist. 564 women aged 40 and over were assigned by chance to either a cetrorelix cycle or the longer standard suppression cycle. The long protocol produced more eggs and more pregnancies, so the authors conclude cetrorelix may be the worse choice at this age. That cuts against the general preference for antagonists, which rests on a lower risk of overstimulation. A general rule is not a rule for everybody.
564 women aged 40 or over randomized to a cetrorelix antagonist protocol or an agonist long protocol. The long protocol produced significantly more oocytes and a higher pregnancy rate, so the authors concluded the antagonist may be the worse choice in older women. A useful counterweight to the general antagonist advantage on hyperstimulation risk.
- Review of studies2016Gonadotrophin-releasing hormone antagonists for assisted reproductive technology
A review that pooled 73 studies in fertility treatment. Blockers like cetrorelix cut the risk of ovarian overstimulation a lot, without lowering live births.
73 RCTs: antagonist protocols substantially reduce OHSS (OR 0.61) without reducing live birth.
Where to buy Cetrorelix
Cetrorelix is an approved medicine. The approved product comes from a pharmacy, with a prescription. The vials below are sold “for research” and are not the approved drug.
No seller we track lists Cetrorelix yet. We read sellers’ public product lists every week, and this section fills in as soon as one does. Every seller, graded
Common questions
Has Cetrorelix been tested in people?
Yes. 564 people given it across 1 completed trial cited here, 0 of which found nothing. Cetrorelix is an FDA-approved drug used in fertility treatment to stop ovulation from happening too early.
What is the Cetrorelix dosage?
Approved medicine. No human dose established for unlabelled uses. Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose. FDA-approved (Cetrotide)
Is Cetrorelix FDA-approved?
FDA-approved (Cetrotide)
How is an antagonist different from agonists like leuprolide?
A blocker like this shuts the GnRH switch right away, with no first burst. Drugs like leuprolide boost the system first, then shut it down. That makes blockers handy in IVF.