Goserelin

Limits on what this shows

• Key negative/null findings: "There was no change in mitochondrial function measured ex vivo or in vivo after six months of ADT," a direct null finding that tempers the proteomic signal: pathway-level expression moved, but measured respiratory function did not, over this timeframe. Baseline mitochondrial respiration positively correlated with preservation of muscle mass and function during treatment.
• At-risk subgroups: Patients with lower baseline mitochondrial respiration/ATP Max showed worse body-composition and performance outcomes during treatment, suggesting baseline fitness may modify vulnerability, though this was not a randomized comparison.
• Counter-evidence on record: Cohort test limitation: the source confirms "GnRH agonist" as the ADT class for 93.2% of patients but does not name goserelin specifically among the agents used, so this is Tier C (class-level) for goserelin, capping the grade at yellow rather than orange or red, even though goserelin is a widely used GnRH agonist in prostate-cancer ADT.

Regulatory status

Not addressed on the label.

Population evidence

Longitudinal cohort, 60 prostate cancer patients starting ADT (59 completing baseline, 57 at 3 months, 55 at 6 months); 93.2% were prescribed a GnRH agonist. This review independently opened the source: Gene Set Enrichment Analysis of skeletal-muscle proteomics found the most downregulated pathways were related to mitochondrial function, with mitochondrial leading-edge proteins showing significant downregulation (p<0.01) at 6 months, and electron transport chain complexes broadly suppressed. [8]

Mechanism

Plausible but not fully isolated: loss of testosterone's known role in supporting mitochondrial gene expression and biogenesis in skeletal muscle is the leading candidate, consistent with the finding's direction, but the source does not isolate testosterone loss as the specific driver, nor does it name goserelin individually among the GnRH agonists used.

Counter-evidence held on record

This entry shares its evidence base with the ATP production entry in the Fails verification section below; see the Overlap map. Do not present this as proof of measurable mitochondrial dysfunction: the same study's direct functional measurements (respiration, ATP Max) did not change.

Limits on what this shows

• Key negative/null findings: None identified specific to goserelin; the broader endometriosis literature (not opened as a primary source here) independently documents elevated oxidative-stress markers in endometriosis patients regardless of treatment, which is the basis for the confounding caution below rather than a null finding per se.
• At-risk subgroups: Women with recurrent, treatment-resistant endometriosis (source population 1); men with prostate cancer on antiandrogenic therapy (source population 2, quantitative detail unverified).
• Counter-evidence on record: Confounding by indication (Hard Rule 6): endometriosis itself, independent of any GnRH agonist treatment, is well documented in the broader gynecologic literature to elevate oxidative-stress markers; source 1 compared goserelin-treated endometriosis patients to healthy controls without an untreated-endometriosis comparison arm, so it cannot isolate the drug's contribution from the disease's own contribution. This is stated explicitly rather than allowing the finding to read as a clean drug effect.

Regulatory status

Not addressed on the label.

Population evidence

(1) Cross-sectional comparative study, 60 Iraqi women with recurrent endometriosis on goserelin acetate (G1) versus 30 healthy women (G2), ages 23-46: malondialdehyde (MDA) 1.97±0.57 vs. 0.65±0.12 µmol/L (P≤0.001); vitamin C 1.12±0.41 vs. 1.68±0.20 mg/dL (P≤0.001); coenzyme Q10 33.04±9.83 vs. 42.31±3.64 ng/mL (P≤0.001); beta-carotene 0.09±0.01 vs. 0.17±0.05 mg/dL (P≤0.001). [6] (2) A separate study measured lipid peroxidation (blood MDA) and antioxidant status (glutathione peroxidase, glutathione reductase, erythrocyte glutathione and vitamin E) in men with prostate cancer and antiandrogenic therapy including goserelin; this review confirmed the study's existence, authors, journal, and that goserelin is specifically indexed to it via two independent bibliographic databases, but the publisher paywall blocked independent verification of its quantitative results, which are not repeated here. [7]

Mechanism

Not drug-isolated in either source. General plausibility rests on the broader literature linking sex-steroid loss to redox changes, the same hormonal-disturbance mechanism class underlying the bone and hematologic findings above, not a goserelin-specific oxidative pathway identified and confirmed in a source this review fully opened.

Counter-evidence held on record

Access limitation disclosed: source 2's full quantitative results (Int Urol Nephrol, 2003) sat behind a publisher paywall; Crossref and OpenAlex metadata confirmed the paper's existence, goserelin's presence in it, and the markers measured (MDA, glutathione peroxidase/reductase, erythrocyte glutathione, vitamin E), but not the numeric results or statistical significance, which are not asserted here. Source 1 is confounded by indication as stated above. This entry is graded yellow, not orange, for both reasons; a follow-up check with institutional access to source 2 could support upgrading it.

Limits on what this shows

• Key negative/null findings: Serum iron itself did not decline in the leuprolide cohort, the single most important number for not recommending empiric iron supplementation on this evidence, and the source authors' own caution that hepcidin may not be the primary driver despite the statistical correlation.
• At-risk subgroups: None established for goserelin specifically; the only directly studied population is men on leuprolide-based ADT, a different drug.
• Counter-evidence on record: No goserelin-specific ferritin, hepcidin, or serum-iron study was located across multiple search attempts (PubMed search-listing pages, Crossref API, both under "goserelin iron ferritin hepcidin" and related phrasings). The label's fibroid-indication iron-supplementation data is not counter-evidence to this entry; it is a different population, different underlying cause of anemia, and different direction, kept separate per the confounding-by-indication principle (see the Oxygen delivery/utilization entry).

Regulatory status

Not addressed on the goserelin label as a drug effect on iron status in men. (The label's fibroid-anemia indication in women pairs goserelin with therapeutic iron supplementation, but that treats a pre-existing bleeding-caused anemia, the opposite clinical context; see the Oxygen delivery/utilization entry above.)

Population evidence

This review independently opened the leuprolide-specific source directly: prospective cohort, 31 men on leuprolide acetate 22.5 mg IM every 3 months versus 39 post-prostatectomy controls, 24-week follow-up. Serum iron did not significantly change (-1.1 µg/dL, P=0.837); ferritin rose 47 ng/mL in the ADT group versus a 14 ng/mL decrease in controls (P<0.001); hepcidin rose about 60% (18 ng/mL, P<0.001) with no change in controls. [5] Tier C for goserelin: leuprolide, not goserelin, was the drug studied.

Mechanism

Proposed but explicitly qualified by the source's own authors: hepcidin-mediated downregulation of ferroportin would be expected to reduce iron release from macrophages/enterocytes to the marrow, but the study's own interpretation states that "the absence of reduced serum iron suggests that hepcidin is not the primary driver of this process," a genuine uncertainty this review is carrying forward rather than smoothing over.

Counter-evidence held on record

This is a different-drug extrapolation of a possible retention/reduced-utilization pattern, not a confirmed goserelin finding and not an iron deficiency. Do not recommend iron supplementation for CAB-associated fatigue or anemia in men on goserelin based on this evidence; the source study's own authors question whether hepcidin is even the primary mechanism in the drug it did study.

Limits on what this shows

• Key negative/null findings: None identified; the paywall limited independent verification of the study's full results, disclosed above.
• At-risk subgroups: None established in humans; this is in vitro chemistry, not a patient population.
• Counter-evidence on record: No human copper-status study of goserelin was found despite repeated search attempts across PubMed search-listing pages and the Crossref API; other results returned for "goserelin copper" were unrelated (a goserelin biosensor using copper-oxide nanoparticles as a detection reagent, and a copper-filtered radiotherapy-beam study), not copper-status findings, and are not cited as supporting evidence.

Regulatory status

Not addressed on the label.

Population evidence

"Impact of the Cu(II) ions on the chemical and biological properties of goserelin: coordination pattern, DNA degradation, oxidative reactivity and in vitro cytotoxicity" (Walencik et al., Journal of Inorganic Biochemistry, 2017). This review independently confirmed the paper's existence, authors, journal, year, and DOI across the Crossref API and OpenAlex API; OpenAlex metadata additionally confirms the study used A549 (lung cancer) cells for the cytotoxicity component. Full quantitative coordination-chemistry, DNA-degradation, and oxidative-reactivity results were not independently accessible (closed access, no PDF at the institutional repository landing page), so exact magnitudes are not asserted here. [9] Tier B: an in vitro chemical/biological study using this medication by name.

Mechanism

Direct coordination chemistry: Cu(II) ions bind goserelin's peptide structure, and the resulting complex is reported to have oxidative and DNA-damaging reactivity in vitro. This is a property of the drug molecule itself reacting with copper ions in solution/cell culture, not a description of how goserelin affects a patient's copper absorption, distribution, or excretion.

Counter-evidence held on record

This is in vitro coordination chemistry between goserelin and copper ions, not a finding about copper deficiency or excess in patients taking goserelin. It should not be read as evidence that goserelin depletes or elevates copper status in the body, and no copper-supplement recommendation follows from it.

Limits on what this shows

• Key negative/null findings: None identified in the accessible source text.
• At-risk subgroups: Men on ADT generally; the source's own framing links the dysbiosis to frailty risk, an outcome-level concern rather than a nutrient-level one, which this entry does not conflate with the microbiome finding itself.
• Counter-evidence on record: No goserelin-specific gut microbiome study was located across multiple search attempts (PubMed search-listing pages, the Europe PMC REST API, which returned repeated HTTP 429 responses mid-review, and the Crossref API, which returned zero goserelin-microbiome matches on a direct query). This absence is disclosed as a genuine gap for goserelin specifically, with the class-level Japanese cohort as the best available supporting evidence.

Regulatory status

Not addressed on the label.

Population evidence

24-week observational study, prostate cancer patients undergoing ADT with sequential fecal sampling at baseline (1-2 weeks pre-ADT) and 1, 4, 12, and 24 weeks post-treatment; 23 patients completed the study, 10 with complete data across all timepoints. This review independently opened the source: alpha- and beta-diversity of gut microbiota decreased significantly at 24 weeks (p=0.017, p<0.001), with increased Proteobacteria, Gammaproteobacteria, Pseudomonadales, and Pseudomonas abundance, and significant changes in urea, lactate, butyrate, 2-hydroxyisobutyrate, and S-adenosylmethionine concentrations (p<0.05); Proteobacteria abundance correlated positively with lactate (R=0.49, p<0.01). [10] Tier C for goserelin: the specific ADT agents were not named in the accessible text.

Mechanism

Proposed by the study authors: testosterone decline indirectly alters the gut environment, producing dysbiosis that "may contribute to an increase in frailty and an increased risk of adverse outcomes." Plausible for any testosterone-suppressing GnRH agonist including goserelin, but not isolated to goserelin specifically.

Counter-evidence held on record

This is class-level evidence for androgen deprivation therapy generally, not a goserelin-specific finding. Access limitation disclosed: Europe PMC REST API queries for a goserelin-specific microbiome search were blocked by proxy-level rate limiting after repeated attempts; a follow-up check when that channel is unconstrained could refine this entry.

Limits on what this shows

• Key negative/null findings: The same trial found no significant hemoglobin decline in patients receiving radiotherapy alone or goserelin monotherapy plus radiotherapy without flutamide-based CAB, which is the key evidence isolating combined androgen blockade (not radiotherapy, not goserelin alone) as the driver. Recovery was slower in African-American patients than White patients in the continued-treatment group (P<0.04), an at-risk subgroup signal.
• At-risk subgroups: Men on combined androgen blockade (goserelin plus an antiandrogen) specifically, rather than goserelin monotherapy; African-American patients showed slower hemoglobin recovery in this cohort.
• Counter-evidence on record: Important confound-by-indication and direction reversal: in women treated with goserelin for fibroid-related uterine bleeding, two independent goserelin-specific randomized trials found the opposite clinical picture. A multicenter trial of premenopausal women with fibroid-related menorrhagia and anemia found a least-squares-mean hemoglobin difference of just over 1 g/dL between goserelin-plus-iron and iron-only groups, and 2.6 g/dL between goserelin-plus-iron and goserelin-only groups, both statistically significant, alongside 37-40% uterine volume reduction versus 7% with iron alone. [2] A separate Phase III randomized, multicenter, double-blind trial confirmed goserelin acetate 10.8 mg plus iron improved hemoglobin/hematocrit versus iron monotherapy prior to fibroid surgery in women with iron-deficiency anemia. [3] Both reflect goserelin stopping fibroid-related bleeding, not a new deficiency, and are population- and indication-dependent, not a universal direction.

Regulatory status

Anemia is listed as a labeled adverse reaction in 1-5% of patients on the ZOLADEX 10.8 mg depot (every 12 weeks); the label does not specify a numeric hemoglobin-decline magnitude or a monitoring schedule.

Population evidence

Prospective multicenter trial, 141 men with prostate cancer at four institutions (mean age 70.9 ± 6.5 years), treated with goserelin acetate 3.6 mg monthly plus flutamide 250 mg three times daily for combined androgen blockade, followed by continued hormone therapy with concurrent pelvic radiotherapy (65-70 Gy over 7-8 weeks). Hemoglobin fell ≥1 g/dL (mean 2.1 ± 0.1 g/dL) in 98/131 patients (75%) after 2 months of CAB alone, deepening to a mean fall of 3.1 ± 0.1 g/dL in 106/131 patients (81%) after 2 further months of CAB plus radiotherapy. [1]

Mechanism

Named by the study authors: the anemia tracked specifically to combined androgen blockade, since it was not observed in the trial's radiotherapy-alone or radiotherapy-plus-goserelin-monotherapy arms; the general endocrine mechanism (loss of testosterone's stimulatory effect on marrow erythroid progenitors) is consistent with this but was not independently re-measured (e.g., via erythropoietin or iron studies) in this specific goserelin cohort.

Counter-evidence held on record

This is a marrow-suppression effect of combined androgen blockade in men, not classic iron-deficiency or nutritional anemia, and it runs in the opposite direction in fibroid patients where goserelin is treating a bleeding-caused anemia. No goserelin-specific ferritin, hepcidin, or serum-iron study was located to establish the mechanism in men (see the Iron entry below, which is class-extrapolated from a different GnRH agonist, not drawn from this same cohort). Do not present iron or B-vitamin supplementation as a routine fix for CAB-associated anemia in men on this evidence.