Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (1,296 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
An anti-androgen that, in the form of its acetate (cyproterone acetate), also has progestational properties. It is used in the treatment of hypersexuality in males, as a palliative in prostatic carcinoma, and, in combination with estrogen, for the therapy of severe acne and hirsutism in females.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Cyproterone, 1alpha,2 alpha,9 beta,10 alpha-Isomer.
Where it fits in the MeSH classification
- Broader topics
- Pregnadienes; Steroids, Chlorinated
- Narrower topics
- Cyproterone Acetate
Related concepts
- Cyproterone Acetate
Research landscape
PubMed indexes 2,787 records tagged with the MeSH heading “Cyproterone” (counts retrieved 2026-10-31). 100 of them (3.6%) were published from 2020 onward, and the busiest period so far is through 1999 with 1,975 records.
Reviews account for 235 records (8.4%) and meta-analyses for 11. Randomized controlled trials number 255 (9.1%) as a share of all records on the topic. Randomized trials make up a comparatively large share of this literature, which means many treatment questions have been tested directly.
Show the data
| Period | Records |
|---|---|
| through 1999 | 1,975 |
| 2000-2009 | 458 |
| 2010-2019 | 254 |
| 2020 onward | 100 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 235 | 8.4% |
| Meta-analyses | 11 | 0.4% |
| Randomized controlled trials | 255 | 9.1% |
Method: PubMed query "Cyproterone"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in drugs and chemicals
Studies of a chemical or drug can answer very different questions: what it is and how it behaves in cells and animals, how the body handles it, and whether it changes outcomes in people. Laboratory and animal findings often do not carry over to patients, and observational studies of exposures are confounded by who uses a substance and why. Nothing on this page is a recommendation to use, avoid, start or stop any substance or medicine; talk to a qualified clinician or pharmacist about your own situation. Check the dose, the species, the comparison group and whether a patient-relevant outcome was measured.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
Phase III pilot study of dose escalation using conformal radiotherapy in prostate cancer: PSA control and side effects [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Radical radiotherapy is a standard form of management of localised prostate cancer.
- Closing excerpt
- Data from this randomised pilot study informed the Data Monitoring Committee of the Medical Research Council RT 01 Trial and the two studies will be combined in subsequent meta-analysis.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (619 words)
Radical radiotherapy is a standard form of management of localised prostate cancer. Conformal treatment planning spares adjacent normal tissues reducing treatment-related side effects and may permit safe dose escalation. We have tested the effects on tumour control and side effects of escalating radiotherapy dose and investigated the appropriate target volume margin. After an initial 3-6 month period of androgen suppression, 126 men were randomised and treated with radiotherapy using a 2 by 2 factorial trial design. The initial radiotherapy tumour target volume included the prostate and base of seminal vesicles (SV) or complete SV depending on SV involvement risk. Treatments were randomised to deliver a dose of 64 Gy with either a 1.0 or 1.5 cm margin around the tumour volume (1.0 and 1.5 cm margin groups) and also to treat either with or without a 10 Gy boost to the prostate alone with no additional margin (64 and 74 Gy groups). Tumour control was monitored by prostate-specific antigen (PSA) testing and clinical examination with additional tests as appropriate. Acute and late side effects of treatment were measured using the Radiation Treatment and Oncology Groups (RTOG) and LENT SOM systems. The results showed that freedom from PSA failure was higher in the 74 Gy group compared to the 64 Gy group, but this did not reach conventional levels of statistical significance with 5-year actuarial control rates of 71% (95% CI 58-81%) in the 74 Gy group vs 59% (95% CI 45-70%) in the 64 Gy group. There were 23 failures in the 74 Gy group and 33 in the 64 Gy group (Hazard ratio 0.64, 95% CI 0.38-1.10, P=0.10). No difference in disease control was seen between the 1.0 and 1.5 cm margin groups (5-year actuarial control rates 67%, 95% CI 53-77% vs 63%, 95% CI 50-74%) with 28 events in each group (Hazard ratio 0.97, 95% CI 0.50-1.86, P=0.94). Acute side effects were generally mild and 18 weeks after treatment, only four and five of the 126 men had persistent > or =Grade 1 bowel or bladder side effects, respectively. Statistically significant increases in acute bladder side effects were seen after treatment in the men receiving 74 Gy (P=0.006), and increases in both acute bowel side effects during treatment (P=0.05) and acute bladder sequelae (P=0.002) were recorded for men in the 1.5 cm margin group. While statistically significant, these differences were of short duration and of doubtful clinical importance. Late bowel side effects (RTOG> or =2) were seen more commonly in the 74 Gy and 1.5 cm margin groups (P=0.02 and P=0.05, respectively) in the first 2 years after randomisation. Similar results were found using the LENT SOM assessments. No significant differences in late bladder side effects were seen between the randomised groups using the RTOG scoring system. Using the LENT SOM instrument, a higher proportion of men treated in the 74 Gy group had Grade > or =3 urinary frequency at 6 and 12 months. Compared to baseline scores, bladder symptoms improved after 6 months or more follow-up in all groups. Sexual function deteriorated after treatment with the number of men reporting some sexual dysfunction (Grade> or =1) increasing from 38% at baseline to 66% at 6 months and 1 year and 81% by year 5. However, no consistent differences were seen between the randomised groups. In conclusion, dose escalation from 64 to 74 Gy using conformal radiotherapy may improve long-term PSA control, but a treatment margin of 1.5 cm is unnecessary and is associated with increased acute bowel and bladder reactions and more late rectal side effects. Data from this randomised pilot study informed the Data Monitoring Committee of the Medical Research Council RT 01 Trial and the two studies will be combined in subsequent meta-analysis.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 15685244 · DOI · PMC2362084
The Menopause Rating Scale (MRS) as outcome measure for hormone treatment? A validation study [2]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe Menopause Rating Scale is a health-related Quality of Life scale developed in the early 1990s and step-by-step validated since then.
- Closing excerpt
- This however needs confirmation in other and better-designed clinical/outcome studies.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (225 words)
BackgroundThe Menopause Rating Scale is a health-related Quality of Life scale developed in the early 1990s and step-by-step validated since then. No methodologically detailed work on the utility of the scale to assess health-related changes after treatment was published before.MethodWe analysed an open, uncontrolled post-marketing study with over 9000 women with pre- and post-treatment data of the MRS scale to critically evaluate the capacity of the scale to measure the health-related effects of hormone treatment independent from the severity of complaints at baseline.ResultsThe improvement of complaints during treatment relative to the baseline score was 36% in average. Patients with little/no complaints before therapy improved by 11%, those with mild complaints at entry by 32%, with moderate by 44%, and with severe symptoms by 55% - compared with the baseline score. We showed that the distribution of complaints in women before therapy returned to norm values after 6 months of hormone treatment. We also provided weak evidence that the MRS results may well predict the assessment of the treating physician. Limitations of the study, however, may have lead to overestimating the utility of the MRS scale as outcome measure.ConclusionThe MRS scale showed some evidence for its ability to measure treatment effects on quality of life across the full range of severity of complaints in aging women. This however needs confirmation in other and better-designed clinical/outcome studies.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 15555079 · DOI · PMC534786
Characterization of atrazine-induced gonadal malformations in African clawed frogs (Xenopus laevis) and comparisons with effects of an androgen antagonist (cyproterone acetate) and exogenous estrogen (17beta-estradiol): Support for the demasculinization/feminization hypothesis [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Atrazine is a potent endocrine disruptor that both chemically castrates and feminizes male amphibians.
- Closing excerpt
- These experimental findings suggest that atrazine-induced gonadal malformations result from the depletion of androgens and production of estrogens, perhaps subsequent to the induction of aromatase by atrazine, a mechanism established in fish, amphibians, reptiles, and mammals (rodents and humans).
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (236 words)
Atrazine is a potent endocrine disruptor that both chemically castrates and feminizes male amphibians. It depletes androgens in adult frogs and reduces androgen-dependent growth of the larynx in developing male larvae. It also disrupts normal gonadal development and feminizes the gonads of developing males. Gonadal malformations induced by atrazine include hermaphrodites and males with multiple testes [single sex polygonadism (SSP)], and effects occur at concentrations as low as 0.1 ppb (microg/L). Here, we describe the frequencies at which these malformations occur and compare them with morphologies induced by the estrogen, 17beta-estradiol (E2) , and the antiandrogen cyproterone acetate, as a first step in testing the hypothesis that the effects of atrazine are a combination of demasculinization and feminization. The various forms of hermaphroditism did not occur in controls. Nonpigmented ovaries, which occurred at relatively high frequencies in atrazine-treated larvae, were found in four individuals out of more than 400 controls examined (1%). Further, we show that several types of gonadal malformations (SSP and three forms of hermaphroditism) are produced by E2 exposure during gonadal differentiation, whereas a final morphology (nonpigmented ovaries) appears to be the result of chemical castration (disruption of androgen synthesis and/or activity) by atrazine. These experimental findings suggest that atrazine-induced gonadal malformations result from the depletion of androgens and production of estrogens, perhaps subsequent to the induction of aromatase by atrazine, a mechanism established in fish, amphibians, reptiles, and mammals (rodents and humans).
Abstract reproduced from the open-access article under the recorded cc0 licence; © the authors. PMID 16818259 · DOI · PMC1874169
Feminizing and masculinizing gender-affirming hormone therapy affects fibrin clot characteristics in opposite directions [4]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe mechanisms behind the increased occurrence of thrombosis associated with gender-affirming hormone treatment (GAHT) are not clarified.
- Closing excerpt
- This large cohort study provides important insights into the mechanisms linking GAHT to thrombotic risk.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (216 words)
BackgroundThe mechanisms behind the increased occurrence of thrombosis associated with gender-affirming hormone treatment (GAHT) are not clarified. We hypothesized that GAHT alters fibrin clot characteristics (formation, lysis, and structure) in a prothrombotic direction.ObjectivesTo investigate changes in ex vivo fibrin clot characteristics after 12 months of feminizing or masculinizing GAHT.MethodsWe included 251 transgender women and 320 transgender men aged >17 years in a prospective cohort study. Clot formation (velocity [V max], maximum absorbance [MA], and overall hemostasis potential [OHP]), clot lysis, and structure (fiber density and diameter) were studied by turbidity at baseline and after 12 months of feminizing GAHT (3 groups of oral/transdermal estradiol and cyproterone acetate) or masculinizing GAHT (7 groups of intramuscular/transdermal testosterone).ResultsIn transgender women, feminizing GAHT increased V max, MA, and OHP, while clot lysis decreased (total group, all P P = .02; Δclot lysis: -5.0%; P = .005). Fiber density and diameter remained unchanged. In transgender men, V max, MA, OHP, and fiber diameter decreased following masculinizing GAHT, whereas clot lysis and fiber density increased (total group, all P ConclusionFeminizing GAHT for 12 months had prothrombotic effects on the fibrin clot, whereas masculinizing GAHT had antithrombotic effects. The procoagulant effect was most evident with oral feminizing GAHT. This large cohort study provides important insights into the mechanisms linking GAHT to thrombotic risk.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42254455 · DOI · PMC13240812
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Maximum androgen blockade in advanced prostate cancer: an overview of the randomised trials. Prostate Cancer Trialists' Collaborative Group [5]
- Research article Long-term treatment of transsexuals with cross-sex hormones: extensive personal experience [6]
- Research article Pharmacology and potential use of cyproterone acetate [7]
- Research article Antiandrogenic drugs [8]
- Research article The antiandrogen cyproterone acetate: discovery, chemistry, basic pharmacology, clinical use and tool in basic research [9]
- Research article Effects of oral contraceptives on metabolic profile in women with polycystic ovary syndrome: A meta-analysis comparing products containing cyproterone acetate with third generation progestins [10]
References
- Dearnaley DP, Hall E, Lawrence D, Huddart RA, Eeles R, Nutting CM, et al.. Phase III pilot study of dose escalation using conformal radiotherapy in prostate cancer: PSA control and side effects. . 2005. PMID 15685244 · DOI · PMC2362084
- Heinemann LA, DoMinh T, Strelow F, Gerbsch S, Schnitker J, Schneider HP. The Menopause Rating Scale (MRS) as outcome measure for hormone treatment? A validation study. . 2004. PMID 15555079 · DOI · PMC534786
- Hayes TB, Stuart AA, Mendoza M, Collins A, Noriega N, Vonk A, et al.. Characterization of atrazine-induced gonadal malformations in African clawed frogs (Xenopus laevis) and comparisons with effects of an androgen antagonist (cyproterone acetate) and exogenous estrogen (17beta-estradiol): Support for the demasculinization/feminization hypothesis. . 2006. PMID 16818259 · DOI · PMC1874169
- Bøgehave M, Glintborg D, Christensen LL, T'Sjoen G, Heijer MD, Andersen MS, et al.. Feminizing and masculinizing gender-affirming hormone therapy affects fibrin clot characteristics in opposite directions. . 2026. PMID 42254455 · DOI · PMC13240812
- . Maximum androgen blockade in advanced prostate cancer: an overview of the randomised trials. Prostate Cancer Trialists' Collaborative Group. Lancet. 2000. PMID 10801170
- Gooren LJ, Giltay EJ, Bunck MC. Long-term treatment of transsexuals with cross-sex hormones: extensive personal experience. J Clin Endocrinol Metab. 2008. PMID 17986639 · DOI
- Neumann F. Pharmacology and potential use of cyproterone acetate. Horm Metab Res. 1977. PMID 66176 · DOI
- McLeod DG. Antiandrogenic drugs. Cancer. 1993. PMID 8428326 · DOI
- Neumann F. The antiandrogen cyproterone acetate: discovery, chemistry, basic pharmacology, clinical use and tool in basic research. Exp Clin Endocrinol. 1994. PMID 8005205 · DOI
- Amiri M, Ramezani Tehrani F, Nahidi F, Kabir A, Azizi F, Carmina E. Effects of oral contraceptives on metabolic profile in women with polycystic ovary syndrome: A meta-analysis comparing products containing cyproterone acetate with third generation progestins. Metabolism. 2017. PMID 28732568 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
See how EvidenceLib is built. Spotted an error? Email support@evidencehelix.com.
Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.