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Fxm3.4
Fluoxymesterone (Halotestin) Research
Mostly mechanism / observational
16 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most Fluoxymesterone (Halotestin) studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from medium-quality randomised trials published 1974–2016.
Based on 16 studies · 11 RCTs
Confidence
Moderate confidence
By outcome
Safety profile
Mostly mechanism / observational12 studies
Androgen replacement (human, legacy)
Mostly mechanism / observational7 studies
Breast-cancer palliation (human)
Mostly mechanism / observational6 studies
Hepatotoxicity
Too few graded studies2 studies
Older research base
Newest study from 2016
197419952016
1RCT1987
Manni A, Santen RJ, Boucher AE, Lipton A, Harvey H, Simmonds M · J Steroid Biochem (1987)
Brubaker LH, Brière J, Laszlo J, Kraut E, Landaw SA, Peterson P · Arch Intern Med (1982)
12Case Study1977
In plain English: Peliosis hepatis was found in 12 patients treated with high-dose oral oxymetholone or fluoxymesterone therapy; in three patients the lesion contributed to fatal hepatic failure, and in one biopsy-confirmed case the lesion regressed after the drug was withdrawn.
Nadell J, Kosek J. · Archives of Pathology & Laboratory Medicine (1977)
Clinicopathologic series of 12 patients who developed peliosis hepatis — blood-filled hepatic cavities — while on high-dose oral 17α-alkylated androgens including fluoxymesterone
In three patients the peliosis contributed to FATAL hepatic failure; in one biopsy-confirmed case the lesion regressed after the drug was stopped, supporting a causal link
A foundational documentation of fluoxymesterone's signature serious hepatotoxicity
13Cohort2016
In plain English: Among 103 patients ... the median progression-free survival was 3.9 months (95% CI 3.2-5.3 months) and the clinical benefit rate was 43% ... fluoxymesterone remains a treatment option in heavily pretreated hormone receptor-positive metastatic breast cancer.
Kono M, Fujii T, Lyons GR, Huo L, Bassett R, Gong Y, Karuturi MS, Tripathy D, Ueno NT. · Breast Cancer Research and Treatment (2016)
Retrospective cohort of 103 patients with hormone-receptor-positive metastatic breast cancer treated with fluoxymesterone after failing contemporary hormonal therapy
Median progression-free survival ~3.9 months with a clinical-benefit rate of 43% — a modest palliative signal in a heavily pretreated population
Androgen-receptor positivity was not significantly associated with the survival outcome
In plain English: The 17 alpha-alkylated steroids (methyltestosterone, oxymetholone, and stanozolol) are directly toxic to hepatocytes ... whereas the nonalkylated steroids were not, supporting the role of 17 alpha-alkylation in anabolic-steroid hepatotoxicity.
Welder AA, Robertson JW, Melchert RB. · Journal of Pharmacological and Toxicological Methods (1995)
In-vitro study exposing primary rat hepatocyte cultures to a panel of anabolic-androgenic steroids (including fluoxymesterone) and measuring LDH release, viability and glutathione depletion
The tested 17α-alkylated steroids (methyltestosterone, oxymetholone, stanozolol) were directly toxic to hepatocytes whereas non-alkylated androgens were not — establishing 17α-alkylation as the mechanism of the class hepatotoxicity fluoxymesterone shares (fluoxymesterone was in the dosed panel but did not itself reach significant toxicity in this assay)
Mechanistic counterpart to the human peliosis-hepatis series: identifies 17α-alkylation as the structural driver of liver injury
In plain English: In men who did not recover spontaneously, sequential treatments were given; only the androgen produced acceptable results and then only at unusually high doses, suggesting androgen insensitivity in these patients.
Van Thiel DH, Gavaler JS, Sanghvi A. · Gastroenterology (1983)
Prospective follow-up study of 60 abstinent alcoholic men with sexual dysfunction, with sequential treatments including the androgen fluoxymesterone in non-spontaneous recoverers
Only the androgen produced acceptable results, and only at unusually high doses — consistent with an androgen-insensitive state in alcohol-related hypogonadism
Illustrates fluoxymesterone's historical men's-vitality / androgen-replacement use and its limits
In plain English: Long-term preventive management with the synthetic androgens fluoxymesterone and oxymetholone reduced the frequency and severity of attacks in severely affected patients with hereditary angioedema.
Davis PJ, Davis FB, Charache P. · The Johns Hopkins Medical Journal (1974)
Open-label clinical experience using the synthetic androgens fluoxymesterone and oxymetholone for long-term prophylaxis in severely affected hereditary-angioedema patients
Androgen therapy reduced attack frequency and severity — an early demonstration of the now-classic androgen effect on C1-inhibitor/complement in HAE
Represents one of fluoxymesterone's legitimate (now largely historical) human indications beyond oncology and hypogonadism