Fixed start (US label trial)
Label- Dose
- 250 mcg
- How often
- Once daily
- How long
- From day 6 of FSH until the hCG day; mean 5.4 days
In the label’s 463-woman trial, premature LH surges occurred in under 1%; ongoing pregnancy 20.3% per attempt.
Approved drugGnRH antagonist
Ganirelix
Orgalutran, Antagon, Fyremadel, Ovamex; Org 37462
- Common dose
- 250 mcg daily during stimulation (about 5 days)
- Cycle
- One 1-week course
- Form
- Ready-made pens
A ten-amino-acid analog of GnRH with six of its building blocks replaced, which turns it into a blocker. It occupies the pituitary’s GnRH receptor without switching it on, so LH falls within hours with no initial surge, holding off ovulation until a trigger shot.
Evidence. FDA-approved since 1999 (first as Antagon, now Organon’s Ganirelix Acetate Injection) and in the EU since 2000 as Orgalutran, to stop premature LH surges during ovarian stimulation for IVF; generic prefilled syringes, including Fyremadel (2018), followed. In the label’s 463-woman trial, premature LH surges occurred in under 1%.
What it’s used for
Approved uses first, then uses tested in people, then claims that rest on animal studies or user reports.
- IVF and assisted reproduction
- LabelApproved to stop premature LH surges during ovarian stimulation. In the US label’s 463-woman trial, surges occurred in under 1%, with ongoing pregnancy in 20.3% per attempt.
- Ovarian hyperstimulation syndrome (OHSS)
- TrialIn a 730-woman trial, OHSS occurred in 2.4% on ganirelix vs 5.9% with a buserelin long protocol. A Cochrane review found less OHSS with antagonists and similar live births.
- Intrauterine insemination (IUI) cycles
- TrialNot approved for this. In 203 women having stimulated IUI, ganirelix cut premature LH rises to 3.9% from 28.0% on placebo, but pregnancy rates were the same (12.6% vs 12.0%).
Label: an approved use. Trial: tested in people, with the result.
Every compound’s uses, by body system: evidence map, and by condition: conditions A to Z.
Status
- Approval
- Approved in the US since July 1999 (Organon, first sold as Antagon) to inhibit premature LH surges in women having controlled ovarian hyperstimulation. Generic prefilled syringes include Fyremadel (2018) and products from several other makers.
- Approval history
- 1999US FDA: Antagon: inhibiting premature LH surges during ovarian stimulation for IVF
- 2000EU (EMA): Orgalutran: preventing premature LH surges during stimulation for assisted reproduction
- 2002Canada: Orgalutran: preventing premature LH surges during ovarian stimulation
- 2018US FDA: Fyremadel: first generic ganirelix approved
- 2022EU (EMA): Ganirelix Gedeon Richter: first centrally authorized generic ganirelix
- European Union
- Prescription only. Orgalutran (2000) and Ganirelix Gedeon Richter (2022) are centrally authorized; Fyremadel and other generics are licensed nationally.
- United Kingdom
- Prescription-only medicines: Fyremadel, Ganirelix Gedeon Richter and Ovamex prefilled syringes, to prevent premature LH surges during ovarian stimulation.
- Canada
- Prescription drug: Orgalutran, marketed since August 2002. Sun Pharma’s SPC-Ganirelix was approved in June 2026 but isn’t yet marketed.
- Australia
- Prescription only (Schedule 4). Orgalutran and several generics are registered; ARX Ganirelix is in shortage until January 2027, with other brands available.
- Sport (WADA 2026)
- Not banned in sportNot named on the 2026 list, and S0 doesn’t apply to an approved drug. S2.2.1 bans GnRH and its agonist analogues in males as testosterone-stimulating peptides; GnRH antagonists, which lower testosterone, aren’t named there or elsewhere.
Sport status follows the WADA Prohibited List in force since January 1, 2026; athletes should confirm with their anti-doping organization. Checked October 5, 2026. Status outside the US checked October 7, 2026 against EMA, MHRA, Health Canada and TGA records. By country: EU, UK, Canada, Australia. Status of every compound.
How it works
Ganirelix blocks the GnRH receptor on the pituitary gland, the switch through which the brain hormone GnRH releases LH and FSH; LH’s mid-cycle surge sets off ovulation. By competing with natural GnRH, it causes a rapid, reversible drop in LH with no initial surge, so daily doses keep ovulation from happening early during IVF stimulation. LH falls more than FSH, and both recover within 48 hours of stopping.
LabelBased on the product label.
Not known
The EU label notes a tendency toward more LH rises in women over 80 kg but too few patients to rule out an effect on outcome. The label trials excluded polycystic ovary syndrome and low ovarian reserve.
Protocol
Label
Ganirelix Acetate Injection, Fyremadel, Orgalutran
250 mcg under the skin once a day in the mid to late follicular phase, usually from day 5 or 6 of FSH stimulation, continued up to the day of the hCG trigger.
Trial
Lambalk 2006
Stimulated intrauterine insemination (IUI): 0.25 mg daily once a follicle reached 14 mm, until the hCG trigger. Not an approved use.
- Frequency
- Once daily
- Route
- Subcutaneous injection (belly or upper thigh)
- Timing
- About the same time each day. The EU label says no more than 30 hours should pass between doses, or between the last dose and the hCG trigger.
- Cycle
- One short course per IVF cycle: a mean of 5.4 days (2–14) in the label trial, stopped at the trigger. The EU label says it was safe and effective over multiple treatment cycles.
One 1-week course, shown over 26 weeks
Common protocols
The ways Ganirelix is most often run, each tagged with where it comes from.
Flexible start (EU label)
Label- Dose
- 0.25 mg
- How often
- Once daily, near the time of the FSH dose but at a different site
- How long
- From day 5 or 6, depending on follicle growth, until the trigger
Starting on day 5 can head off an early LH rise in strong responders. Doses must be no more than 30 hours apart.
With an agonist trigger
Trial- Dose
- 0.25 mg daily, then a single GnRH agonist dose instead of hCG
- How often
- Daily, then one trigger injection
- How long
- One cycle
In 47 women, leuprorelin 0.5 mg or triptorelin 0.2 mg matured as many eggs as hCG; the approach is used to lower OHSS risk.
Stimulated IUI (not approved)
Trial- Dose
- 0.25 mg
- How often
- Once daily from a 14 mm follicle
- How long
- Until the hCG trigger
Cut premature LH rises to 3.9% from 28.0% on placebo in 203 women, but ongoing pregnancy rates didn’t change (12.6% vs 12.0%).
Taking it
Where it goes
Under the skin of the belly around the navel or the upper thigh, varying the site a little each time (US label). The EU label says to use a different site from the FSH injection.
If you miss a dose
The labels give no missed-dose rule. The EU label warns that more than 30 hours between doses, or before the hCG trigger, may allow an early LH surge, so ask the clinic how to proceed, and don’t double up.
What to expect
- Hours after a dose
In volunteers, LH fell by up to 74% within 4 hours (FSH 32% and estradiol 25% by 16 hours), with no initial surge.
Label - Days 2–3
Steady blood levels are reached after about 3 daily doses.
Label - During stimulation
Premature LH surges in under 1% of 463 women in the US label trial; LH and progesterone rises in 0.3–1.2% vs 0.8% with agonists (EU label).
Label - After the last dose
LH and FSH recover fully within 48 hours of stopping.
Label
Side effects and what to do
Injection-site redness or swelling (EU label: moderate or severe at 1 hour in 12% vs 25% with an agonist)
Usually gone within 4 hours. Vary the site a little each time.
Gynecological belly pain 4.8% and headache 3.0% (US label, 794 women)
Partly from the stimulation itself; severe or worsening pain needs prompt review.
Ovarian hyperstimulation syndrome (US label: 2.4%)
A risk of the stimulation. Belly swelling, rapid weight gain or breathlessness need prompt care.
Vaginal bleeding 1.8% and nausea 1.1% (US label)
Usually mild.
Allergic reactions, including rare anaphylaxis
Can occur with the first dose. The label says to stop it; hives, swelling or trouble breathing need emergency care.
Stop and get medical help
Get emergency help for hives, face or throat swelling, or trouble breathing, especially after the first dose. Severe belly pain or swelling, rapid weight gain, shortness of breath or passing very little urine can mean severe OHSS.
Can it cause …?
The side effects people ask about most, answered one by one. Each answer says where it comes from.
- Tiredness
- LabelMalaise, a general unwell feeling, is uncommon (under 1 in 100) in the EU label; tiredness isn’t listed in the US label.
- Headache
- LabelHeadache: 3.0% of 794 women in the US trials; uncommon in the EU label.
- Nausea or vomiting
- LabelNausea: 1.1% of 794 women in the US trials; uncommon in the EU label.
- Diarrhea or constipation
- LabelStomach or bowel pain: 1.0% in the US trials. Diarrhea and constipation aren’t listed.
- Acne, rash or skin changes
- LabelLocal redness or swelling is very common (moderate or severe in 12% vs 25% with an agonist); rarely rash, hives or worsening of existing eczema (EU label).
- Water retention or swelling
- LabelInjection-site swelling is common. Facial swelling or angioedema signals an allergic reaction; belly swelling with weight gain can mean OHSS (2.4% in US trials).
- Liver strain
- LabelNot listed as a side effect; total bilirubin shifted slightly downward in trials. The EU label rules it out with moderate or severe liver impairment.
- Kidney problems
- LabelNot listed as a side effect. The EU label rules it out with moderate or severe kidney impairment, which wasn’t studied.
- Cancer risk
- LabelLong-term animal cancer studies weren’t done; gene-damage tests were negative. IVF exposure lasts only days per cycle.
- DizzinessTrouble sleepingHair lossJoint or muscle painAnxiety, low mood or irritabilityLow or high blood sugarFast heartbeat or blood pressure changesMore hunger
- Not reportedNot listed in the US or EU labels; the US trials gave it to 794 women for 1–14 days per IVF cycle.
Label: from the prescribing information. Not reported: studied in people and not reported. A side effect that hasn’t been reported can still happen, especially with long or high-dose use. Any of these across every compound: the side-effect finder.
Who should avoid it
What its label rules out or warns about, most important first.
- Allergy to ganirelix or GnRH drugs
- LabelRuled out by the labels. Anaphylaxis, angioedema and hives have occurred, as early as the first dose; it isn’t advised with severe allergic conditions.
- Latex allergy
- LabelRuled out for syringes whose needle shield contains dry natural rubber latex, which touches the product (US label).
- Pregnancy or breastfeeding
- LabelPregnancy is ruled out and must be excluded first; in rats and rabbits it increased litter loss. The US label says not to use it while breastfeeding, and the EU label rules it out.
- Moderate or severe kidney or liver impairment
- LabelRuled out by the EU label because such patients were excluded from trials; the US label notes its pharmacokinetics haven’t been studied in them.
- Polycystic ovaries or low ovarian reserve
- LabelThe US label trials set out to exclude these women, so the label’s results don’t cover them.
- Women weighing more than 80 kg
- LabelThe EU label notes a tendency toward more LH rises at higher body weight, though no effect on outcome was seen.
Interactions
Only interactions stated on a product label or measured in a human study are listed.
- Gonadotropins used for stimulation (FSH)
- LabelGiven at about the same time but not mixed, and at different sites. Because ganirelix lowers the body’s own FSH, the US label says FSH doses may need adjusting.
- Drugs that can release histamine
- LabelThe EU label says interactions with commonly used drugs, including histamine-releasing ones, can’t be excluded; no interaction studies were done.
Label: a product label rules it out, warns about it or lists the interaction. This isn’t a complete list: a pharmacist or doctor can check a specific medicine or condition. Every documented interaction, by medicine: drug interactions.
Special situations
What the label and studies say about pregnancy, breastfeeding, kidney and liver problems, age and surgery.
- Pregnancy
- LabelRuled out: pregnancy must be excluded first. In rats and rabbits it increased litter loss without malformations; a study of over 1,000 newborns found anomaly rates similar to those after agonist cycles.
- Breastfeeding
- LabelNot for use while breastfeeding (US label) and ruled out in the EU; whether it passes into milk isn’t known.
- Kidney problems
- LabelNot studied; the EU label rules it out with moderate or severe kidney impairment. About 22% of a dose leaves in urine.
- Liver problems
- LabelNot studied; the EU label rules it out with moderate or severe liver impairment.
- Older adults
- LabelThe trials didn’t include enough women 65 or older to judge, the US label says.
- Children and teens
- LabelNot studied in anyone under 18; its pharmacokinetics in children haven’t been determined (US label).
- Surgery and anesthesia
- PrecautionNo label advice. Egg retrieval is usually done under sedation; tell the team about all fertility drugs. LH and FSH recover within 48 hours of the last dose.
Label: what the prescribing information says. Precaution: not studied, so the caution follows from how it works or from a related drug. Ages are given as approved or studied; this site never gives doses for children. Across every compound: pregnancy, breastfeeding, kidney disease, liver disease, older adults and surgery.
Tracking and pairing
Worth tracking
- Follicle growth on ultrasound and estradiol (routine IVF monitoring)
- LH if an early surge is suspected
- Signs of OHSS: belly swelling or pain, weight gain, breathlessness
- Allergy symptoms after the first dose; latex allergy before starting
Often paired with
- hCG
Standard pairing: daily ganirelix holds off ovulation until a single hCG injection triggers final egg maturation (label).
- Leuprolide
After ganirelix, a single 0.5 mg leuprorelin dose can replace hCG as the trigger; in 47 women it matured as many eggs (85% vs 86% mature), the approach used to lower OHSS risk.
Human studies
5 key published human studies, with how many people took part. Animal studies aren’t listed here.
-
GnRH analog treatment lasted a median 5 vs 26 days; LH rises 2.8% vs 1.3%; ongoing pregnancy 20.3% vs 25.7% per attempt; OHSS 2.4% vs 5.9%.
- Design
- Randomized open-label non-inferiority trial vs a long protocol of intranasal buserelin (European Orgalutran Study Group)
- Dose
- 0.25 mg daily (2:1 randomization) vs buserelin
- Length
- One stimulation cycle
Borm and Mannaerts, Hum Reprod 2000, PMID 10875855
-
Eggs retrieved 11.6 vs 14.1; ongoing pregnancy 30.8% vs 36.4% per attempt; moderate injection-site reactions 11.9% vs 24.4%.
- Design
- Randomized open-label phase III trial vs a long protocol of leuprolide (North American Ganirelix Study Group)
- Dose
- 0.25 mg daily vs leuprolide long protocol
- Length
- One stimulation cycle
Fluker et al., Fertil Steril 2001, PMID 11163814
-
The ganirelix regimen was 17 days shorter; ongoing pregnancy 31.0% vs 33.9% per attempt, identical implantation (22.9%), half as many local skin reactions.
- Design
- Randomized trial vs a long protocol of triptorelin (European and Middle East Orgalutran Study Group)
- Dose
- 0.25 mg daily (236 women) vs triptorelin 0.1 mg daily (119)
- Length
- One stimulation cycle
European and Middle East Orgalutran Study Group, Hum Reprod 2001, PMID 11278211
-
LH rose to 10 IU/L or more in 16%, 9% and 1.4% at 0.0625, 0.125 and 0.25 mg; 0.25 mg gave the best pregnancy rate, which fell at higher doses.
- Design
- Double-blind randomized dose-finding trial
- Dose
- 0.0625 to 2 mg daily
- Length
- One stimulation cycle
Ganirelix Dose-Finding Study Group, Hum Reprod 1998, PMID 9853849
-
Premature LH rises 3.9% vs 28.0% on placebo; ongoing pregnancy 12.6% vs 12.0%.
- Design
- Randomized double-blind placebo-controlled trial in stimulated intrauterine insemination
- Dose
- 0.25 mg daily from a 14 mm follicle vs placebo
- Length
- One cycle
Lambalk et al., Hum Reprod 2006, PMID 16361296
Trials under way
Registered trials that are still running, or that finished without published results, most important first. Checked on ClinicalTrials.gov, October 7, 2026.
Oral SHR7280 tablets vs ganirelix injections in 317 women having IVF or ICSI: eggs retrieved and LH surge prevention
Completed May 2025; no results posted
Oral micronized progesterone vs ganirelix to prevent the LH surge in 150 women having ovarian stimulation: mature eggs
Completed August 2025; no results posted
Oral linzagolix vs injectable antagonists (ganirelix or cetrorelix) in 120 women having IVF: mature eggs retrieved
Not yet recruiting; start planned September 2026, completion expected December 2026
A single low dose of ganirelix to damp LH pulses and lower androgens in 20 lean women with polycystic ovary syndrome
Completed February 2025; no results posted
Ganirelix used to switch off ovarian hormones in 30 midlife women, to study estradiol, stress, sleep and blood vessel function
Recruiting; completion expected October 2027
Every compound’s registered trials: trials under way.
Limits of the evidence
Approval rests on a 333-woman dose-finding trial and a 730-woman comparison with a buserelin long protocol; two more trials (313 and 355 women) compared it with leuprolide and triptorelin. Each covered one IVF cycle of about 5 days, and the label trials excluded polycystic ovaries and low ovarian reserve. Over 1,000 newborns have been followed; uses outside IVF, such as IUI, rest on single trials.
How it’s supplied
Ready-made prefilled syringes of 250 mcg in 0.5 mL, one dose each (Organon’s ganirelix, Fyremadel and other generics). The pen measures each dose, so there’s nothing to mix or draw up.
Ganirelix comes ready to use: each prefilled syringe holds one 250 mcg dose in 0.5 mL, so nothing is mixed. Small air bubbles are expected and needn’t be removed (US label).
Datasheet
- Half-life
- about 13–16 hours LabelAfter 250 mcg under the skin in healthy women: 12.8 hours after one dose and 16.2 hours with daily dosing (US label); about 13 hours in the EU label. Steady levels are reached in 2–3 days.
- Type
- Peptide, 10 amino acids
- Molecular weight
- 1,570.4 g/mol
- Formula
- C80H113ClN18O13
- Sequence
- (Ac-D-Nal)-(D-Cpa)-(D-Pal)-SY-(D-hArg(Et2))-L-(hArg(Et2))-P-(D-Ala)-NH2Nal = 3-(2-naphthyl)alanine, Cpa = 4-chlorophenylalanine, Pal = 3-(3-pyridyl)alanine, hArg(Et2) = diethyl-homoarginine
- Storage before use
- US: at 25 °C (excursions 15–30 °C), protected from light; Fyremadel 20–25 °C. EU: protected from light, not frozen.
- After mixing or opening
- Not mixed: each prefilled syringe is used once and discarded.
- Half-life: Ganirelix Acetate Injection prescribing information, Table I (Organon, DailyMed, November 2025); Orgalutran EU summary of product characteristics, section 5.2
- Molecule: Ganirelix label (sequence; 1,570.4 as anhydrous free base); PubChem CID 16130957; FDA GSRS UNII IX503L9WN0. Products contain the acetate.
- Storage: Label Ganirelix Acetate Injection (Organon) and Fyremadel labels, How Supplied (DailyMed); Orgalutran EU summary of product characteristics, section 6.4
Every compound side by side: the half-life chart and the storage chart.
Identifiers
- DrugBank
- DB06785
- ATC code
- H01CC01
- Development codes
- Org 37462 (Organon)
- CAS number
- 124904-93-4 (ganirelix); 129311-55-3 (acetate)
- UNII (FDA)
- IX503L9WN0 (ganirelix); 56U7906FQW (acetate)
- PubChem CID
- 16130957 (ganirelix); 23724914 (acetate)
- Brand names
- Orgalutran; Antagon, now sold as Ganirelix Acetate Injection (US); Fyremadel; Ovamex; generic prefilled syringes
- First described
- Designed at Syntex to avoid earlier blockers’ histamine release (Nestor et al., 1992); first approved as Antagon, US, 1999.
Every compound’s numbers: the identifiers table.
Product form and quality
Each prefilled syringe holds 250 mcg of ganirelix acetate in 0.5 mL; doses are stated as the acetate. Some syringes have a needle shield containing natural rubber latex (US label).
Cautions
- Label: allergic reactions, including anaphylaxis, angioedema and hives, as early as the first dose; not advised with severe allergic conditions.
- Some syringes have a needle shield made with natural rubber latex, which rules them out for people with a latex allergy (US label).
- Ruled out in pregnancy; the EU label also rules it out when breastfeeding and with moderate or severe kidney or liver impairment.
- Ovarian hyperstimulation syndrome (OHSS) is a risk of the stimulation itself: 2.4% in the US trials.
- Gaps of more than 30 hours between doses, or before the trigger, may allow an early LH surge (EU label).
Questions
What is ganirelix?
A ten-amino-acid analog of GnRH with six of its building blocks replaced, which turns it into a blocker. It occupies the pituitary’s GnRH receptor without switching it on, so LH falls within hours with no initial surge, holding off ovulation until a trigger shot.
How does ganirelix work?
Ganirelix blocks the GnRH receptor on the pituitary gland, the switch through which the brain hormone GnRH releases LH and FSH; LH’s mid-cycle surge sets off ovulation. By competing with natural GnRH, it causes a rapid, reversible drop in LH with no initial surge, so daily doses keep ovulation from happening early during IVF stimulation. LH falls more than FSH, and both recover within 48 hours of stopping. The EU label notes a tendency toward more LH rises in women over 80 kg but too few patients to rule out an effect on outcome. The label trials excluded polycystic ovary syndrome and low ovarian reserve.
Is ganirelix FDA-approved?
Approved in the US since July 1999 (Organon, first sold as Antagon) to inhibit premature LH surges in women having controlled ovarian hyperstimulation. Generic prefilled syringes include Fyremadel (2018) and products from several other makers.
What is the usual ganirelix dose?
From the label (Ganirelix Acetate Injection, Fyremadel, Orgalutran): 250 mcg under the skin once a day in the mid to late follicular phase, usually from day 5 or 6 of FSH stimulation, continued up to the day of the hCG trigger. From human studies (Lambalk 2006): Stimulated intrauterine insemination (IUI): 0.25 mg daily once a follicle reached 14 mm, until the hCG trigger. Not an approved use. These are the amounts sources reference, not recommendations.
How is ganirelix given?
Ready-made prefilled syringes of 250 mcg in 0.5 mL, one dose each (Organon’s ganirelix, Fyremadel and other generics), injected under the skin. About the same time each day. The EU label says no more than 30 hours should pass between doses, or between the last dose and the hCG trigger. The pen measures each dose, so there’s nothing to mix.
Who should avoid ganirelix?
Allergy to ganirelix or GnRH drugs: Ruled out by the labels. Anaphylaxis, angioedema and hives have occurred, as early as the first dose; it isn’t advised with severe allergic conditions. Latex allergy: Ruled out for syringes whose needle shield contains dry natural rubber latex, which touches the product (US label). Pregnancy or breastfeeding: Pregnancy is ruled out and must be excluded first; in rats and rabbits it increased litter loss. The US label says not to use it while breastfeeding, and the EU label rules it out. The “Who should avoid it” section lists 3 more groups and 2 interactions.
What is the half-life of ganirelix?
About 13–16 hours, according to the prescribing information. After 250 mcg under the skin in healthy women: 12.8 hours after one dose and 16.2 hours with daily dosing (US label); about 13 hours in the EU label. Steady levels are reached in 2–3 days.
How should ganirelix be stored?
Before mixing: US: at 25 °C (excursions 15–30 °C), protected from light; Fyremadel 20–25 °C. EU: protected from light, not frozen. Not mixed: each prefilled syringe is used once and discarded.
Is ganirelix banned in sport?
No. Not named on the 2026 list, and S0 doesn’t apply to an approved drug. S2.2.1 bans GnRH and its agonist analogues in males as testosterone-stimulating peptides; GnRH antagonists, which lower testosterone, aren’t named there or elsewhere.
Has ganirelix been studied in people?
Yes. The human studies section lists 5 published studies. The largest, from 2000, included 730 people. GnRH analog treatment lasted a median 5 vs 26 days; LH rises 2.8% vs 1.3%; ongoing pregnancy 20.3% vs 25.7% per attempt; OHSS 2.4% vs 5.9%.
How long has ganirelix been studied in people?
Label Use lasts about 5 days per cycle (2–14 in trials). The EU label says it was safe and effective over multiple treatment cycles.
Does ganirelix come in other forms, like a pill or nasal spray?
Trial Injected under the skin from prefilled syringes. A needle-free jet injector gave the same blood levels in a 16-woman study but isn’t approved; there is no oral or nasal form.
Can you drink alcohol while taking ganirelix?
No study No data; the labels don’t mention alcohol.
Can ganirelix be taken with semaglutide or tirzepatide?
Label No study has combined them, and neither label lists an interaction. Semaglutide’s labels advise stopping it at least 2 months before a planned pregnancy, which affects timing around IVF.
What happens if you take too much ganirelix?
Label No overdoses reported; single doses up to 12 mg caused no systemic reactions, and overdose may prolong its effect (EU label). Call Poison Help (1-800-222-1222), or emergency services for severe symptoms.
Sources
- Ganirelix Acetate Injection prescribing information (Organon, rev. 2/2024; DailyMed, November 13, 2025)
- Fyremadel (ganirelix acetate) injection prescribing information (Sun Pharma for Ferring, DailyMed, January 2025)
- Orgalutran EU summary of product characteristics (EMA)
- Drugs@FDA: ganirelix acetate injection (NDA 021057, July 29, 1999); Fyremadel (ANDA 204246, November 30, 2018) and later generics
- Fluker et al., ganirelix vs leuprolide, North American phase III trial (Fertil Steril 2001) PMID 11163814
- Borm and Mannaerts, European Orgalutran Study Group trial vs buserelin (Hum Reprod 2000) PMID 10875855
For the protocol details
- Ganirelix Acetate Injection prescribing information, clinical pharmacology, clinical studies, precautions and adverse reactions (Organon, DailyMed, November 2025)
- Orgalutran EU summary of product characteristics, sections 4.2, 4.4, 4.8 and 5.1 (EMA)
- Fauser et al., GnRH agonist trigger after ganirelix cotreatment (J Clin Endocrinol Metab 2002) PMID 11836309
- Lambalk et al., ganirelix in stimulated intrauterine insemination, placebo-controlled trial (Hum Reprod 2006) PMID 16361296
- Wilcox et al., single-dose cetrorelix vs daily ganirelix (Fertil Steril 2005) PMID 16009165
For how it works, who should avoid it and the limits of the evidence
- Ganirelix Acetate Injection prescribing information, clinical pharmacology, clinical studies, contraindications and precautions (Organon, DailyMed, November 2025)
- Orgalutran EU summary of product characteristics, sections 4.2–4.6 and 5.1 (EMA)
For uses, the side-effect questions, special situations, trials, identifiers and status outside the US
- Ganirelix Acetate Injection prescribing information, all sections (Organon, rev. 2/2024; DailyMed, November 13, 2025)
- Fyremadel prescribing information (Sun Pharma for Ferring, DailyMed, January 2025)
- Orgalutran EU summary of product characteristics, sections 4.3–4.9, 5.1 and 5.2 (EMA)
- Al-Inany et al., GnRH antagonists for assisted reproductive technology, Cochrane review (Cochrane Database Syst Rev 2016) PMID 27126581
- Oberyé et al., ganirelix by needle-free injector vs needle (Hum Reprod 2000) PMID 10655292
- Nestor et al., GnRH antagonists with low histamine-releasing activity, including ganirelix (J Med Chem 1992) PMID 1279174
- Semaglutide (Wegovy and Ozempic) prescribing information, section 8.1 (DailyMed, 2026)
- FDA Global Substance Registration System records for ganirelix and ganirelix acetate; PubChem; WHO ATC index
- EMA medicines data (Orgalutran, May 2000; Ganirelix Gedeon Richter, July 15, 2022) and French public medicines database (checked October 8, 2026)
- UK summaries of product characteristics on EMC: Fyremadel, Ganirelix Gedeon Richter and Ovamex (checked October 8, 2026)
- Health Canada Drug Product Database entries for Orgalutran and SPC-Ganirelix (checked October 8, 2026)
- TGA product information search and medicine shortage database; Poisons Standard, October 2026 (ganirelix in Schedule 4)
- ClinicalTrials.gov registry entries for the trials listed (checked October 8, 2026)