Cetrorelix

Limits on what this shows

• Key negative/null findings: This entry's central finding is itself the null result: no significant difference in apoptosis by two independent assays (Annexin V, TUNEL) between cetrorelix and an agonist comparator, despite a real, significant difference in follicular steroid output between the two arms, arguing that cetrorelix's endocrine effect does not translate into a measurable granulosa-cell apoptotic or mitochondrial-integrity difference at these doses.
• At-risk subgroups: None identified specific to cetrorelix in the source reviewed.

Regulatory status

Not addressed in either label; granulosa-cell apoptosis and mitochondrial function are not label-level endpoints.

Population evidence

Giampietro et al., randomized prospective study, Fertility and Sterility, 2006, n=32 women with primary infertility undergoing assisted reproduction (cetrorelix 0.25 mg daily versus the GnRH agonist triptorelin). Annexin V+/PI- cells: 7.87 ± 1.27% (agonist) versus 9.92 ± 0.98% (antagonist), p>0.05. TUNEL-positive cells: 18.00 ± 3.87% versus 20.50 ± 6.56%, p>0.05. Flow cytometric DNA analysis and transmission electron microscopy (which can reveal mitochondrial ultrastructure) were also performed, with comparable findings reported between groups.

Mechanism

Not named as a positive burden mechanism, because none was found; apoptosis in granulosa cells is substantially mitochondria-dependent (intrinsic pathway), so a null difference on this endpoint is the most directly relevant cetrorelix-specific data available on this category, even though it does not isolate mitochondrial structure or respiration specifically.

Counter-evidence held on record

Counter-evidence on record This is an active-comparator trial (antagonist versus agonist), not versus no treatment or a non-stimulated cycle, so it cannot rule out a mitochondrial effect common to both protocols (for example from the gonadotropin stimulation itself, which both arms received) or establish cetrorelix's absolute effect in isolation. A separate title, "GnRH antagonist cetrorelix inhibits mitochondria-dependent apoptosis triggered by chemotherapy in granulosa cells of rats" (PMID 20417958), was identified via search as a potentially relevant animal mechanism study, but PubMed's page returned a reCAPTCHA bot-verification challenge and the Europe PMC and Semantic Scholar API lookups were rate-limited (HTTP 429) on every attempt this session; the source was never opened and is therefore not cited as evidence for this entry, per this protocol's prohibition on citing unopened sources. Framing caution This is graded yellow as a reassuring context flag on the best available direct data, not as evidence of either mitochondrial harm or mitochondrial protection from cetrorelix. No supplement or antioxidant is recommended from this entry.

Limits on what this shows

• Key negative/null findings: The cetrorelix-specific Tulic et al. trial is itself a null finding on all three markers tested and is carried forward deliberately as the required counter-evidence to the multicycle signal; it also reported that patients without induced oxidative stress had better delivery rates (82% versus 68%), which is a fertility-outcome association rather than a cetrorelix-attributable effect.
• At-risk subgroups: Patients undergoing repeated (3 or more) antagonist-protocol IVF cycles, per the duration-response pattern in the multicycle study; this has not been confirmed as cetrorelix-specific since the antagonist agent used was not stated.

Regulatory status

Not addressed in either label; no oxidative-stress or antioxidant marker appears in the FDA or EMA labeling for cetrorelix.

Population evidence

Cetrorelix-specific: Tulic et al., Journal of Medical Biochemistry, 2017, prospective clinical study, n=82 (58 on cetrorelix up to 0.25 mg/day, 24 on a GnRH agonist). Superoxide dismutase (SOD): 14.5 U/L (antagonist) versus 14.08 U/L (agonist), p=0.289. Malondialdehyde (MDA): 1.71 versus 1.78 μmol/L, p=0.561. Sulfhydryl (SH) groups: 0.47 versus 0.51 mmol/L, p=0.207. None reached significance. Class-level, agent unconfirmed: Ma et al., Human Cell, 2021, n=145 across four antagonist-protocol groups by cycle count (1 cycle n=42; 2 cycles n=37; 3 cycles n=45; 4-5 cycles n=21). Comparing cycles 1-2 to cycles 3-5: 8-hydroxy-2-deoxyguanosine (8-OHdG) and SOD were significantly increased, while catalase (CAT) and glutathione peroxidase (GSH-Px) were significantly decreased (p<0.05); clinical pregnancy rate fell from 50.0% (cycle 1) to 23.8% (cycles 4-5) over the same groups.

Mechanism

Plausible by extrapolation for the multicycle finding only: repeated controlled ovarian stimulation itself (follicular growth, ovulation induction, and repeated venipuncture/injection stress) is understood in general reproductive physiology to generate reactive oxygen species in follicular fluid and granulosa cells; the study did not isolate cetrorelix from ganirelix or state which antagonist agent its patients received, so the mechanism is class-level rather than confirmed cetrorelix-specific.

Counter-evidence held on record

Counter-evidence on record The single-cycle, cetrorelix-specific trial (Tulic et al.) found no oxidative-stress signal at all versus an agonist comparator, which bounds how much weight the class-level multicycle finding can carry for cetrorelix specifically; both are active-comparator or duration-comparator designs, not comparisons against no ovarian stimulation, so neither isolates cetrorelix's absolute contribution to oxidative stress from the contribution of gonadotropin-driven ovarian stimulation itself, which both study designs shared across all arms. Framing caution This does not establish that cetrorelix itself raises oxidative stress markers in a standard single-cycle course. No antioxidant supplement or dose is recommended from this entry; the multicycle signal is a reasonable prompt for clinical attention in patients undergoing repeated IVF cycles generally, not a cetrorelix-specific dosing consideration.

Limits on what this shows

• Why no grade: This category was re-searched with a fresh tool budget. PubMed's search-listing pages (unlike the prior attempt, which hit a reCAPTCHA challenge) were reachable this session and returned real results for multiple phrasings. "cetrorelix AND copper" and a broader "GnRH antagonist AND (copper OR ceruloplasmin OR trace element)" query surfaced a cluster of papers on copper-GnRH (Cu-GnRH) molecular complexes (PMID 26551063, 31931118, 3010974); these were opened via the OpenAlex works-by-PMID endpoint and confirmed, by title and available metadata, to study copper binding to the native/endogenous GnRH decapeptide as a neuroendocrine signaling tool in rat pituitary cells, using antide or an unnamed early antagonist only to block the complex's receptor action. None studies cetrorelix, and none measure the body's copper status as a drug effect, so none pass the cohort test or fit this category's definition and none are cited as evidence. The same search surfaced a 2026 paper, Zec et al., "Redox homeostasis in human follicular fluid: a comparison of modified natural cycle and controlled ovarian stimulation in idiopathic infertility" (Reproductive Biology, PMID 42320453), whose PubMed snippet references copper concentrations in follicular fluid; this is a genuinely promising, current lead, but the full text is paywalled on ScienceDirect and neither the DOI redirect nor the OpenAlex record yielded an abstract or results this session, so it is not cited as evidence either. No circulating consumer claim tying cetrorelix to copper status was identified. Both conditions for ungraded are met, on a broader and more successful search than the prior attempt.

Tooling note

This session's channel mix differs from the prior attempt: PubMed's search-listing pages and the OpenAlex works-by-PMID endpoint were reachable and returned genuine content. The Europe PMC REST API (HTTP 429, then HTTP 503 on retry), the Semantic Scholar API (HTTP 429), the OpenAlex free-text search endpoint (HTTP 429), and the Crossref API (HTTP 429) were blocked on every attempt this session. WebSearch was unavailable this session because the shared 200-call session budget was already exhausted before this revision began. A future revision should prioritize opening the Zec et al. 2026 paper (DOI 10.1016/j.repbio.2026.101244) through institutional or publisher access before treating this gap as permanent.

Limits on what this shows

• Why no grade: This category was re-searched with a fresh tool budget. PubMed's search-listing pages were reachable this session, unlike the prior attempt's reCAPTCHA block. Targeted queries ("cetrorelix AND ferritin/iron status/hemoglobin/anemia") returned only two results, neither relevant: a rat diabetic-nephropathy model that used cetrorelix solely as a tool to induce hypogonadism, with no iron or hemoglobin endpoint reported (PMID 30970225), and a male spermatogenesis-suppression trial whose snippet shows no iron, ferritin, or hemoglobin data (PMID 11726576). A broader trace-element query surfaced a heavy-metal-and-trace-element ART-outcome study that plausibly includes iron in its panel (Tolunay et al. 2016, PMID 26802253), but its OpenAlex record has no abstract text, its individual PubMed page is blocked, and its snippet gives no indication it is stratified by GnRH-antagonist protocol rather than confounded by the underlying infertility diagnosis (Hard Rule 6), so it is not cited as evidence. No cetrorelix-specific or GnRH-antagonist-class study measuring iron, ferritin, transferrin, or hemoglobin as a drug effect was found. No circulating consumer claim tying cetrorelix to iron status was identified either. Both conditions for ungraded are met, on a genuinely wider search than the prior attempt.

Tooling note

This session's channel mix differs from the prior attempt: PubMed's search-listing pages and the OpenAlex works-by-PMID endpoint were reachable and returned genuine content; the Europe PMC REST API, Semantic Scholar API, OpenAlex free-text search, and Crossref API were blocked (HTTP 429/503) on every attempt, and WebSearch was unavailable because the shared session budget was already exhausted before this revision began. Distinguish this entry from Oxygen delivery/utilization above, unchanged from the prior note: the OHSS/hematocrit finding graded there is a fluid-shift and vascular-permeability effect, not an iron-status or erythropoiesis finding, and should not be read as implying anything about this Iron entry.

Limits on what this shows

• Why no grade: This category was re-searched with a fresh tool budget. PubMed's search-listing pages were reachable this session, unlike the prior attempt's reCAPTCHA block. "cetrorelix AND (microbiome OR microbiota OR gut flora OR intestinal)" returned four results. The most on-topic, an in vitro peptide-metabolism study comparing kidney and intestinal S9 tissue fractions using cetrorelix as one of three model compounds (Jyrkka et al. 2022, PMID 36630767, opened via the OpenAlex works-by-PMID endpoint), measures how intestinal tissue enzymatically degrades cetrorelix, an absorption/metabolism question, not any effect of cetrorelix on gut microbial composition or diversity, so it does not fit this category's definition and is not cited as evidence. The other three hits (a rat estrus-cycle electromyography study, a cetrorelix G-protein/pituitary study, and a kisspeptin/GPR54 gut-motility study in which cetrorelix served only as a negative control with no effect) address gastrointestinal physiology in passing but not microbiome composition. No cetrorelix-specific or GnRH-antagonist-class study measuring gut microbial composition, diversity, or function was found. No circulating consumer claim tying cetrorelix to gut microbiome effects was identified either. Both conditions for ungraded are met, on a genuinely wider search than the prior attempt.

Tooling note

This session's channel mix differs from the prior attempt: PubMed's search-listing pages and the OpenAlex works-by-PMID endpoint were reachable and returned genuine content; the Europe PMC REST API, Semantic Scholar API, OpenAlex free-text search, and Crossref API were blocked (HTTP 429/503) on every attempt, and WebSearch was unavailable because the shared session budget was already exhausted before this revision began. Cetrorelix's very short typical exposure window (5-10 days) and subcutaneous, non-gastrointestinal route still lower the a priori plausibility of a measurable microbiome effect relative to a chronically dosed oral drug, but this reasoning was not used as a substitute for the genuine search documented above.

Limits on what this shows

• Key negative/null findings: The source abstract accessible this session did not report hematocrit or hemoglobin values directly for either arm; the finding is an OHSS-incidence outcome, not a directly measured hematologic value, which is why this is graded yellow (context flag) rather than orange.
• At-risk subgroups: High ovarian responders (high antral follicle count, high AMH, polycystic-ovary-syndrome-type response) are the subgroup for whom OHSS, and therefore this protective comparison, is most clinically relevant; this is standard ART risk stratification, not a cetrorelix-specific finding.

Regulatory status

Not framed in nutrient terms by either label. The FDA and EMA labels list OHSS itself as the most common adverse reaction (FDA Table 3: 3.5%, WHO Grade II/III, n=949; EMA: common mild-moderate, uncommon severe), with no hemoglobin, hematocrit, or anemia entry in the adverse-reaction tables of either label.

Population evidence

Ludwig et al., prospective randomized trial, n=273 (85 on the GnRH agonist buserelin, long luteal protocol; 188 on cetrorelix, multiple-dose antagonist protocol). Moderate-to-severe (WHO Grade II/III) OHSS: 1.1% with cetrorelix versus 6.5% with buserelin (p=0.03). Patients withheld hCG for threatened OHSS: 1.6% (cetrorelix) versus 5.9% (buserelin).

Mechanism

Named: cetrorelix's immediate, reversible LH-receptor antagonism (versus an agonist's initial flare followed by downregulation) is associated with a less exaggerated multifollicular response and lower peak estradiol in some protocols, which is mechanistically linked in the OHSS literature to reduced vascular permeability and less third-space fluid shift; hematocrit rises in OHSS as a secondary consequence of that fluid shift concentrating the existing red-cell mass, not from any change in erythropoiesis or iron handling.

Counter-evidence held on record

Counter-evidence on record This is an active-comparator trial (antagonist versus agonist), not a comparison against no treatment, so it cannot establish what cetrorelix's absolute effect on hematocrit is in isolation, only its effect relative to the agonist protocol it replaced. Per Hard Rule 2, OHSS prevention is cetrorelix's own intended pharmacologic consequence of LH suppression, not a nutrient-deficiency or nutrient-excess finding, and is written up here strictly as a mechanism/risk clarification. Framing caution Do not read this as evidence that cetrorelix affects hemoglobin, red-cell production, or iron status. It does not. It is a real, drug-specific reduction in the incidence of a hemoconcentration-associated syndrome relative to an agonist comparator, included here because hematocrit falls within this category's defined scope. No iron, hydration, or blood-volume intervention is recommended from this entry; any suspected OHSS should be evaluated by the treating fertility physician.

Limits on what this shows

• Why no grade: This category was re-searched with a fresh tool budget. PubMed's search-listing pages were reachable this session, unlike the prior attempt's reCAPTCHA block. A direct query, "cetrorelix AND (ATP production OR ATP synthesis OR adenosine triphosphate OR mitochondrial respiration OR oxidative phosphorylation)," returned zero results, a genuine negative rather than a blocked attempt. Two cetrorelix-specific papers surfaced under looser searches were opened via the OpenAlex works-by-PMID endpoint and judged not to fit this category's definition (mitochondrial ATP synthesis or cellular energy output specifically). Collado et al. 2004 (PMID 14767559) found cetrorelix depot did not alter basal adenylate cyclase activity in rat ovary, breast, or pituitary tissue, only agonist-response modulation for unrelated neuropeptides; adenylate cyclase converts ATP to cAMP as a signaling step and is not a measure of ATP production capacity, so this null finding on a different enzyme system is not used as evidence here. Chen et al. 2005 (PMID 15536154) found cetrorelix increased poly(ADP-ribose) polymerase (PARP) expression as an apoptosis marker in cultured human leiomyoma (uterine fibroid) cells; PARP is a DNA-repair/apoptosis marker, and the study did not measure ATP content, ATP synthesis, or mitochondrial respiration directly, so it is not used as ATP-production evidence either. No study directly measuring ATP synthesis capacity, cellular ATP content, or mitochondrial respiration in cetrorelix-exposed cells or tissue was located. No circulating consumer claim tying cetrorelix to ATP or "low energy" was identified either. Both conditions for ungraded are met, now against a genuine zero-result direct query rather than a blocked one.

Tooling note

This session's channel mix differs from the prior attempt: PubMed's search-listing pages and the OpenAlex works-by-PMID endpoint were reachable and returned genuine content; the Europe PMC REST API, Semantic Scholar API, OpenAlex free-text search, and Crossref API were blocked (HTTP 429/503) on every attempt, and WebSearch was unavailable because the shared session budget was already exhausted before this revision began. Apoptosis (graded under Mitochondrial burden above) and ATP synthesis capacity remain related but distinct endpoints per Hard Rule 7's requirement to keep these two categories independent; the PARP finding above is a further apoptosis-pathway data point, not an ATP finding, and does not change the Mitochondrial burden entry, which this revision left untouched per its scope.