Fluoxymesterone

updated

Fluoxymesterone is an oral 17-alpha-methyl androgen that FDA approved as HALOTESTIN in 1956; every US approval has since been withdrawn after the holders stopped marketing it. Randomized trials in breast cancer and dialysis anemia had mixed results, and a PubMed search on 9 October 2026 found no study of muscle, strength or athletic performance in healthy people. The label carries liver warnings for 17-alpha-alkyl androgens and states the drug has not been shown safe and effective for enhancing athletic performance.

17-alpha-methyl androgen (testosterone derivative)

  • FDA approved HALOTESTIN under NDA 010611 on 15 October 1956; approval of that application was withdrawn effective 18 June 2009, and every fluoxymesterone product in Drugs@FDA is marked discontinued.
  • In 238 postmenopausal women with metastatic breast cancer, adding fluoxymesterone to tamoxifen gave objective responses in 54% versus 42% (P = 0.07) and median time to progression of 11.6 versus 6.5 months (P = 0.03); survival was similar overall.
  • As adjuvant therapy in 541 women with resected ER-positive breast cancer, 1 year of fluoxymesterone added to tamoxifen did not improve relapse-free or overall survival, and virilization was more common.
  • The label warns that prolonged high doses of 17-alpha-alkyl androgens have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis.
  • A PubMed search on 9 October 2026 returned 53 records on fluoxymesterone with muscle, strength or performance terms; by title, none tested muscle mass, strength or athletic performance in healthy people or athletes.
  • The label gives an oral half-life of about 9.2 hours, while a 6-person study measured 2.0 hours; the two values conflict.

What is fluoxymesterone, and is it still approved?

FDA approved fluoxymesterone as HALOTESTIN on 15 October 1956. Approval of the HALOTESTIN application was withdrawn effective 18 June 2009, and every product in the FDA record is marked discontinued.

FDA approved HALOTESTIN tablets under NDA 010611 (Pharmacia and Upjohn) on 15 October 1956. Drugs@FDA lists 8 fluoxymesterone applications, including the generics ANDROID-F (ANDA 087196, approved 6 July 1981) and Upsher-Smith tablets (ANDA 088342, approved 21 October 1983). Every listed product is marked discontinued.

Approval of the HALOTESTIN application (NDA 10-611) was withdrawn effective 18 June 2009, and approval of the Upsher-Smith generic (ANDA 088342) was withdrawn as of 25 May 2022 (Federal Register notice 2022-08744). In both notices the holders had told FDA the products were no longer marketed and asked for withdrawal, and neither notice states a safety finding. Because every US approval has been withdrawn, any product sold now is not an FDA-approved fluoxymesterone product.

The HALOTESTIN label on DailyMed, version effective 6 February 2006, lists replacement therapy in men with primary or hypogonadotropic hypogonadism and delayed puberty, and palliation of androgen-responsive recurrent breast cancer in women 1 to 5 years postmenopausal or with a proven hormone-dependent tumor. Status outside the United States is not established here.

Fluoxymesterone is C20H29FO3 (336.4 g/mol, CAS 76-43-7), a 9-alpha-fluoro, 11-beta-hydroxy, 17-alpha-methyl testosterone derivative. No salt or ester forms are involved.

Drugs@FDA: HALOTESTIN approved 15 October 1956, 8 applications, all discontinued

Regulatory record

U.S. Food and Drug Administration. Drugs@FDA application record for NDA 010611 (HALOTESTIN, fluoxymesterone), with related fluoxymesterone applications. Dates read from the openFDA Drugs@FDA records.

FDA approved HALOTESTIN tablets under NDA 010611 (Pharmacia and Upjohn) on 15 October 1956. Drugs@FDA lists 8 fluoxymesterone applications, including the generics ANDROID-F (ANDA 087196, approved 6 July 1981) and Upsher-Smith tablets (ANDA 088342, approved 21 October 1983). Every listed product is marked discontinued.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Approvals from 1956 to 1983
Study design
FDA application records
Funding
not stated in the source

These records give approval dates and product status. Indications come from the product label.

Read the original source
Federal Register: HALOTESTIN approval withdrawn 18 June 2009; Upsher-Smith generic 25 May 2022

Regulatory record

Federal Register, 19 May 2009, notice E9-11628, withdrawal of approval of new drug applications including NDA 10-611 (HALOTESTIN). The 2022 withdrawal of the Upsher-Smith generic (ANDA 088342) is Federal Register notice 2022-08744.

Approval of the HALOTESTIN application (NDA 10-611) was withdrawn effective 18 June 2009, and approval of the Upsher-Smith generic (ANDA 088342, 10 mg) was withdrawn as of 25 May 2022. In both notices the holders had told FDA the products were no longer marketed and asked for withdrawal. Neither notice states a safety finding.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Withdrawals effective 2009 and 2022
Study design
Federal Register notices
Funding
not stated in the source

The withdrawals followed holder requests after marketing stopped. They are not safety findings.

Read the original source
HALOTESTIN label, version effective 6 February 2006: uses, warnings, athletic-use statement

FDA prescribing information

DailyMed, U.S. National Library of Medicine. HALOTESTIN (fluoxymesterone) oral tablets, prescribing information, label version effective 6 February 2006. Set ID 09bafc2d-1893-4618-86dc-e9403407cd41.

The label lists replacement therapy in men with primary or hypogonadotropic hypogonadism and delayed puberty, and palliation of androgen-responsive recurrent breast cancer in women 1 to 5 years postmenopausal or with a proven hormone-dependent tumor. The oral half-life is given as about 9.2 hours. Fluoxymesterone is Schedule III under the Anabolic Steroids Control Act, and the label states it has not been shown to be safe and effective for enhancing athletic performance and should not be used for that purpose. It warns that prolonged high doses of androgens, principally the 17-alpha-alkyl androgens, have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening, and that cholestatic hepatitis and jaundice may occur; it advises periodic liver function tests. Other warnings and precautions cover edema with or without heart failure in patients with cardiac, renal or hepatic disease, retention of sodium, chloride and water, polycythemia, virilization in women that may not reverse, hypercalcemia in breast cancer, and a class statement that serum cholesterol may increase during androgen therapy. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

Participants / model
Men with hypogonadism or delayed puberty; women with androgen-responsive recurrent breast cancer; label populations
Treatment
HALOTESTIN oral tablets
Follow-up
Label version effective 6 February 2006
Study design
FDA prescribing information
Funding
not stated in the source

The page gives no label doses. The cholesterol line is a class statement, not a measured fluoxymesterone effect.

Read the original source
PubChem CID 6446: C20H29FO3, 336.4 g/mol

Chemical identity record

National Library of Medicine. PubChem compound record CID 6446 (fluoxymesterone).

Fluoxymesterone: PubChem CID 6446, C20H29FO3, 336.4 g/mol, CAS 76-43-7, a 9-alpha-fluoro, 11-beta-hydroxy, 17-alpha-methyl testosterone derivative (label molecular weight 336.45). No salt or ester forms are involved.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Identity record only; it says nothing about efficacy or safety. Because every US approval has been withdrawn, any product sold now is not an FDA-approved fluoxymesterone product.

Read the original source

What did the breast cancer and dialysis anemia trials find?

Added to tamoxifen in metastatic breast cancer, fluoxymesterone lengthened median time to progression (11.6 versus 6.5 months) without a survival difference. As adjuvant therapy it gave no benefit, and in dialysis patients it raised hematocrit less than injected androgens.

In 238 postmenopausal women with metastatic breast cancer randomized to tamoxifen or tamoxifen plus fluoxymesterone (each 10 mg twice daily), objective responses were 42% (50 of 119) versus 54% (64 of 119) (P = 0.07), and median time to progression was 6.5 versus 11.6 months (P = 0.03). Response duration and survival were similar overall.

In 541 postmenopausal women with resected ER-positive early breast cancer, adding fluoxymesterone 10 mg twice daily for 1 year to 5 years of tamoxifen did not improve relapse-free survival (HR 0.84, 95% CI 0.64 to 1.10) or overall survival (HR 0.89, 95% CI 0.67 to 1.18) at a median 11.4-year follow-up, and virilization was more common.

In a randomized trial in anemic adults on maintenance hemodialysis, who received up to three androgens in successive 6-month periods (77 completed the first period), injected nandrolone decanoate and testosterone enanthate raised hematocrit in clearly more patients, and by more, than oral oxymetholone or fluoxymesterone.

All three studies enrolled people with cancer or kidney failure, so none applies to healthy people.

Metastatic breast cancer: 238 women, response 54% versus 42%, time to progression 11.6 versus 6.5 months

Randomized controlled trial

Ingle JN et al. Cancer. 1991;67(4):886-91. PMID 1991261.

Objective responses were 42% (50 of 119) on tamoxifen versus 54% (64 of 119) on tamoxifen plus fluoxymesterone (P = 0.07), and median time to progression was 6.5 versus 11.6 months (P = 0.03). Response duration and survival were similar overall.

Participants / model
238 postmenopausal women with metastatic breast cancer
Treatment
Oral tamoxifen or tamoxifen plus fluoxymesterone (each 10 mg twice daily)
Follow-up
not stated in the source
Study design
Randomized trial
Funding
not stated in the source

A cancer population; the result does not apply to healthy people. Endpoints were objective response, time to progression and survival.

Read the original source
Adjuvant trial: 541 women, no gain in relapse-free or overall survival

Randomized controlled trial

Ingle JN et al. Breast Cancer Res Treat. 2006;98(2):217-22. PMID 16538529.

Adding fluoxymesterone did not improve relapse-free survival (HR 0.84, 95% CI 0.64 to 1.10) or overall survival (HR 0.89, 95% CI 0.67 to 1.18) at a median 11.4-year follow-up, and virilization was more common.

Participants / model
541 postmenopausal women with resected ER-positive early breast cancer
Treatment
Oral fluoxymesterone 10 mg twice daily for 1 year added to 5 years of tamoxifen
Follow-up
1 year of fluoxymesterone; median follow-up 11.4 years
Study design
Randomized trial
Funding
not stated in the source

A cancer population; the result does not apply to healthy people.

Read the original source
Dialysis anemia: oral fluoxymesterone raised hematocrit less than injected androgens

Randomized controlled trial

Neff MS et al. N Engl J Med. 1981;304(15):871-5. PMID 7010161.

Injected nandrolone decanoate and testosterone enanthate raised hematocrit in clearly more patients, and by more, than oral oxymetholone or fluoxymesterone.

Participants / model
Anemic adults on maintenance hemodialysis; 77 completed the first 6-month period
Treatment
Up to three androgens in successive 6-month periods, among oral fluoxymesterone, oral oxymetholone, injected nandrolone decanoate and injected testosterone enanthate
Follow-up
6-month periods
Study design
Randomized trial
Funding
not stated in the source

A dialysis population; hematocrit response, not strength or muscle, was the endpoint.

Read the original source

Does fluoxymesterone hold up as a strength drug with a poor liver, lipid and blood pressure profile?

The liver concern has support in label warnings on 17-alpha-alkyl androgens and a high-dose case series. The lipid and blood pressure concerns have no fluoxymesterone-specific HDL, LDL or blood pressure data behind them, and no human study tested muscle, strength or athletic performance.

Sellers describe fluoxymesterone as an extremely androgenic strength and contest drug with little emphasis on muscle gain and a very poor liver, lipid and blood pressure profile.

A PubMed search on 9 October 2026 for fluoxymesterone with muscle, strength, lean body mass, body composition, athlete, athletic, performance or nitrogen balance terms returned 53 records. By title, none tested muscle mass, strength or athletic performance in healthy people or athletes; they covered breast and prostate cancer, anemia, doping-control metabolism and detection, rodent and cell studies, and a 1989 case report in Kennedy-Alter-Sung syndrome. A 1974 pharmacologic evaluation in normal men sat outside this search and has no abstract, so its endpoints are unknown. The strength and contest use has no trial behind it among these records.

The label states that fluoxymesterone has not been shown to be safe and effective for enhancing athletic performance and should not be used for that purpose. It is Schedule III under the Anabolic Steroids Control Act.

The liver concern is covered in the risks section below, and the lipid and blood pressure concerns in the cholesterol and blood pressure section.

PubMed search, 9 October 2026: 53 records, none on muscle or strength in healthy people

PubMed search record

PubMed search run on 9 October 2026: fluoxymesterone AND (muscle OR strength OR lean body mass OR body composition OR athletes OR athletic OR performance OR nitrogen balance). 53 records returned.

The search returned 53 records. By title, none tested muscle mass, strength or athletic performance in healthy people or athletes; they covered breast and prostate cancer, anemia, doping-control metabolism and detection, rodent and cell studies, and a 1989 case report in Kennedy-Alter-Sung syndrome. A 1974 pharmacologic evaluation in normal men sat outside this search and has no abstract, so its endpoints are unknown. The strength and contest use has no trial behind it among these records.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Search run on 9 October 2026
Study design
Literature search
Funding
not stated in the source

A search result shows what PubMed returned on that date. It is not proof that no unindexed study exists.

Read the original source
HALOTESTIN label, version effective 6 February 2006: uses, warnings, athletic-use statement

FDA prescribing information

DailyMed, U.S. National Library of Medicine. HALOTESTIN (fluoxymesterone) oral tablets, prescribing information, label version effective 6 February 2006. Set ID 09bafc2d-1893-4618-86dc-e9403407cd41.

The label lists replacement therapy in men with primary or hypogonadotropic hypogonadism and delayed puberty, and palliation of androgen-responsive recurrent breast cancer in women 1 to 5 years postmenopausal or with a proven hormone-dependent tumor. The oral half-life is given as about 9.2 hours. Fluoxymesterone is Schedule III under the Anabolic Steroids Control Act, and the label states it has not been shown to be safe and effective for enhancing athletic performance and should not be used for that purpose. It warns that prolonged high doses of androgens, principally the 17-alpha-alkyl androgens, have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening, and that cholestatic hepatitis and jaundice may occur; it advises periodic liver function tests. Other warnings and precautions cover edema with or without heart failure in patients with cardiac, renal or hepatic disease, retention of sodium, chloride and water, polycythemia, virilization in women that may not reverse, hypercalcemia in breast cancer, and a class statement that serum cholesterol may increase during androgen therapy. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

Participants / model
Men with hypogonadism or delayed puberty; women with androgen-responsive recurrent breast cancer; label populations
Treatment
HALOTESTIN oral tablets
Follow-up
Label version effective 6 February 2006
Study design
FDA prescribing information
Funding
not stated in the source

The page gives no label doses. The cholesterol line is a class statement, not a measured fluoxymesterone effect.

Read the original source
Peliosis hepatis: 12 patients on high-dose oral androgens, drugs not separated

Case report

Nadell J et al. Arch Pathol Lab Med. 1977;101(8):405-10. PMID 577673.

A pathology series described peliosis hepatis in 12 patients treated with high-dose oxymetholone or fluoxymesterone. Liver failure was the primary cause of death in 3, the lesion was an incidental autopsy finding in 8, and in 1 biopsy-diagnosed case it was absent at autopsy 2 years after the androgen was stopped. The abstract does not separate cases by drug.

Participants / model
12 patients on high-dose oral androgen therapy
Treatment
Oral oxymetholone or fluoxymesterone, high dose
Follow-up
not stated in the source
Study design
Pathology case series
Funding
not stated in the source

Class-level liver evidence; the abstract does not say which cases involved fluoxymesterone.

Read the original source
PubMed search, 9 October 2026: 20 records, no HDL or LDL measurement in people

PubMed search record

PubMed search run on 9 October 2026: fluoxymesterone AND (lipoprotein OR HDL OR cholesterol OR lipids OR lipid). 20 records returned.

The search returned 20 records. The only abstract with a blood lipid measure was an uncontrolled study of 30 hemodialysis patients given 20 mg a day for 4 months, which reported no change in serum cholesterol, body weight or albumin, with hirsutism and voice hoarsening as side effects. Four human reports have no abstract, including a 1973 report on lipid metabolism in uremic patients given oral androgens and a 1974 pharmacologic evaluation in normal men, so their findings are unknown. The rest covered sebum, tumor markers, rats, dogs, cells, genetic syndromes or chemistry.

Participants / model
Records returned, not a population; 30 hemodialysis patients in the one lipid abstract
Treatment
Not applicable; oral fluoxymesterone 20 mg a day in the dialysis study
Follow-up
Search run on 9 October 2026
Study design
Literature search
Funding
not stated in the source

No fluoxymesterone study measuring HDL or LDL in people was found. The label's cholesterol line is a class statement.

Read the original source
PubMed search, 9 October 2026: 3 records, no blood pressure measurement in people

PubMed search record

PubMed search run on 9 October 2026: fluoxymesterone AND (blood pressure OR hypertension). 3 records returned.

The search returned 3 records: the laboratory enzyme study, a 1985 assay and bioavailability paper, and a 1970 pituitary hormone study. The label documents sodium and water retention and edema, but no measured blood pressure effect.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Search run on 9 October 2026
Study design
Literature search
Funding
not stated in the source

A search result shows what PubMed returned on that date. It is not proof that no unindexed study exists.

Read the original source

How does fluoxymesterone work, and what does the body do with it?

Fluoxymesterone is a 17-alpha-methyl testosterone derivative. The label gives an oral half-life of about 9.2 hours, a 6-person study measured 2.0 hours, and the sources do not reconcile the two.

Fluoxymesterone is a 9-alpha-fluoro, 11-beta-hydroxy, 17-alpha-methyl testosterone derivative. The label's liver warnings apply to prolonged high doses of androgens, principally the 17-alpha-alkyl androgens.

In enzyme and cell assays, fluoxymesterone potently inhibited human 11-beta-hydroxysteroid dehydrogenase 2, the enzyme that inactivates cortisol (IC50 60 to 100 nM in lysates; 160 nM in SW-620 cells and 530 nM in MCF-7 cells), and inhibited rodent forms much more weakly. The authors propose that this could let cortisol activate mineralocorticoid receptors and contribute to hypertension. No blood pressure was measured, so this is a laboratory finding, not a measured effect in people.

The label gives an oral half-life of about 9.2 hours. In a 6-person crossover study of 10 mg tablets taken orally or buccally (health status not stated in the abstract), Cmax ranged from 40 to 150 ng/mL, tmax was 1 to 2 hours and the harmonic mean half-life was 2.0 hours; oral Cmax and AUC were 80% and 76% of the buccal values. The two half-life values conflict, and this page does not choose between them.

In the dialysis anemia trial, oral fluoxymesterone raised hematocrit in fewer patients, and by less, than injected nandrolone decanoate or testosterone enanthate.

PubChem CID 6446: C20H29FO3, 336.4 g/mol

Chemical identity record

National Library of Medicine. PubChem compound record CID 6446 (fluoxymesterone).

Fluoxymesterone: PubChem CID 6446, C20H29FO3, 336.4 g/mol, CAS 76-43-7, a 9-alpha-fluoro, 11-beta-hydroxy, 17-alpha-methyl testosterone derivative (label molecular weight 336.45). No salt or ester forms are involved.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Identity record only; it says nothing about efficacy or safety. Because every US approval has been withdrawn, any product sold now is not an FDA-approved fluoxymesterone product.

Read the original source
HALOTESTIN label, version effective 6 February 2006: uses, warnings, athletic-use statement

FDA prescribing information

DailyMed, U.S. National Library of Medicine. HALOTESTIN (fluoxymesterone) oral tablets, prescribing information, label version effective 6 February 2006. Set ID 09bafc2d-1893-4618-86dc-e9403407cd41.

The label lists replacement therapy in men with primary or hypogonadotropic hypogonadism and delayed puberty, and palliation of androgen-responsive recurrent breast cancer in women 1 to 5 years postmenopausal or with a proven hormone-dependent tumor. The oral half-life is given as about 9.2 hours. Fluoxymesterone is Schedule III under the Anabolic Steroids Control Act, and the label states it has not been shown to be safe and effective for enhancing athletic performance and should not be used for that purpose. It warns that prolonged high doses of androgens, principally the 17-alpha-alkyl androgens, have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening, and that cholestatic hepatitis and jaundice may occur; it advises periodic liver function tests. Other warnings and precautions cover edema with or without heart failure in patients with cardiac, renal or hepatic disease, retention of sodium, chloride and water, polycythemia, virilization in women that may not reverse, hypercalcemia in breast cancer, and a class statement that serum cholesterol may increase during androgen therapy. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

Participants / model
Men with hypogonadism or delayed puberty; women with androgen-responsive recurrent breast cancer; label populations
Treatment
HALOTESTIN oral tablets
Follow-up
Label version effective 6 February 2006
Study design
FDA prescribing information
Funding
not stated in the source

The page gives no label doses. The cholesterol line is a class statement, not a measured fluoxymesterone effect.

Read the original source
Laboratory study: potent inhibition of human 11-beta-HSD2, no blood pressure measured

Cell study

Fürstenberger C et al. Toxicol Sci. 2012;126(2):353-61. PMID 22273746.

Fluoxymesterone potently inhibited human 11-beta-hydroxysteroid dehydrogenase 2, the enzyme that inactivates cortisol (IC50 60 to 100 nM in lysates; 160 nM in SW-620 cells and 530 nM in MCF-7 cells), and inhibited rodent forms much more weakly. The authors propose that this could let cortisol activate mineralocorticoid receptors and contribute to hypertension. No blood pressure was measured.

Participants / model
Recombinant human enzyme and human cell lines; rodent enzyme comparison
Treatment
In vitro fluoxymesterone exposure
Follow-up
not stated in the source
Study design
Original laboratory study
Funding
not stated in the source

This is a laboratory finding and a hypothesis, not a measured effect on blood pressure in people.

Read the original source
6-person crossover PK study: half-life 2.0 hours, conflicts with the label's 9.2 hours

Human study

Capponi VJ et al. J Pharm Sci. 1985;74(3):308-11. PMID 4009439.

In a 6-person crossover bioavailability study of 10 mg tablets taken orally or buccally, Cmax ranged from 40 to 150 ng/mL with tmax of 1 to 2 hours, and the harmonic mean half-life was 2.0 hours. Oral Cmax and AUC were 80% and 76% of the buccal values. This half-life is much shorter than the label's 9.2 hours.

Participants / model
6 subjects (health status not stated in the abstract)
Treatment
Single 10 mg tablet, oral or buccal
Follow-up
Single-dose crossover
Study design
Crossover bioavailability study
Funding
not stated in the source

The 2.0-hour half-life conflicts with the label's 9.2 hours, and the sources do not reconcile the two.

Read the original source
Dialysis anemia: oral fluoxymesterone raised hematocrit less than injected androgens

Randomized controlled trial

Neff MS et al. N Engl J Med. 1981;304(15):871-5. PMID 7010161.

Injected nandrolone decanoate and testosterone enanthate raised hematocrit in clearly more patients, and by more, than oral oxymetholone or fluoxymesterone.

Participants / model
Anemic adults on maintenance hemodialysis; 77 completed the first 6-month period
Treatment
Up to three androgens in successive 6-month periods, among oral fluoxymesterone, oral oxymetholone, injected nandrolone decanoate and injected testosterone enanthate
Follow-up
6-month periods
Study design
Randomized trial
Funding
not stated in the source

A dialysis population; hematocrit response, not strength or muscle, was the endpoint.

Read the original source

What do the studies show about cholesterol and blood pressure?

No fluoxymesterone study measuring HDL, LDL or blood pressure in people was found. The label's cholesterol line is a class statement, and its fluid retention warning is not a measured blood pressure effect.

A PubMed search on 9 October 2026 for fluoxymesterone with lipoprotein, HDL, cholesterol or lipid terms returned 20 records. The only abstract with a blood lipid measure was an uncontrolled study of 30 hemodialysis patients given 20 mg a day for 4 months, which reported no change in serum cholesterol, body weight or albumin, with hirsutism and voice hoarsening as side effects. Four human reports have no abstract, including a 1973 report on lipid metabolism in uremic patients given oral androgens and a 1974 pharmacologic evaluation in normal men, so their findings are unknown. The rest covered sebum, tumor markers, rats, dogs, cells, genetic syndromes or chemistry.

The label states that serum cholesterol may increase during androgen therapy. That is a class statement, not a measured fluoxymesterone effect.

A PubMed search on 9 October 2026 for fluoxymesterone with blood pressure or hypertension terms returned 3 records: the laboratory enzyme study described above, a 1985 assay and bioavailability paper, and a 1970 pituitary hormone study. The label documents sodium, chloride and water retention and edema, but no measured blood pressure effect.

PubMed search, 9 October 2026: 20 records, no HDL or LDL measurement in people

PubMed search record

PubMed search run on 9 October 2026: fluoxymesterone AND (lipoprotein OR HDL OR cholesterol OR lipids OR lipid). 20 records returned.

The search returned 20 records. The only abstract with a blood lipid measure was an uncontrolled study of 30 hemodialysis patients given 20 mg a day for 4 months, which reported no change in serum cholesterol, body weight or albumin, with hirsutism and voice hoarsening as side effects. Four human reports have no abstract, including a 1973 report on lipid metabolism in uremic patients given oral androgens and a 1974 pharmacologic evaluation in normal men, so their findings are unknown. The rest covered sebum, tumor markers, rats, dogs, cells, genetic syndromes or chemistry.

Participants / model
Records returned, not a population; 30 hemodialysis patients in the one lipid abstract
Treatment
Not applicable; oral fluoxymesterone 20 mg a day in the dialysis study
Follow-up
Search run on 9 October 2026
Study design
Literature search
Funding
not stated in the source

No fluoxymesterone study measuring HDL or LDL in people was found. The label's cholesterol line is a class statement.

Read the original source
PubMed search, 9 October 2026: 3 records, no blood pressure measurement in people

PubMed search record

PubMed search run on 9 October 2026: fluoxymesterone AND (blood pressure OR hypertension). 3 records returned.

The search returned 3 records: the laboratory enzyme study, a 1985 assay and bioavailability paper, and a 1970 pituitary hormone study. The label documents sodium and water retention and edema, but no measured blood pressure effect.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Search run on 9 October 2026
Study design
Literature search
Funding
not stated in the source

A search result shows what PubMed returned on that date. It is not proof that no unindexed study exists.

Read the original source
HALOTESTIN label, version effective 6 February 2006: uses, warnings, athletic-use statement

FDA prescribing information

DailyMed, U.S. National Library of Medicine. HALOTESTIN (fluoxymesterone) oral tablets, prescribing information, label version effective 6 February 2006. Set ID 09bafc2d-1893-4618-86dc-e9403407cd41.

The label lists replacement therapy in men with primary or hypogonadotropic hypogonadism and delayed puberty, and palliation of androgen-responsive recurrent breast cancer in women 1 to 5 years postmenopausal or with a proven hormone-dependent tumor. The oral half-life is given as about 9.2 hours. Fluoxymesterone is Schedule III under the Anabolic Steroids Control Act, and the label states it has not been shown to be safe and effective for enhancing athletic performance and should not be used for that purpose. It warns that prolonged high doses of androgens, principally the 17-alpha-alkyl androgens, have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening, and that cholestatic hepatitis and jaundice may occur; it advises periodic liver function tests. Other warnings and precautions cover edema with or without heart failure in patients with cardiac, renal or hepatic disease, retention of sodium, chloride and water, polycythemia, virilization in women that may not reverse, hypercalcemia in breast cancer, and a class statement that serum cholesterol may increase during androgen therapy. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

Participants / model
Men with hypogonadism or delayed puberty; women with androgen-responsive recurrent breast cancer; label populations
Treatment
HALOTESTIN oral tablets
Follow-up
Label version effective 6 February 2006
Study design
FDA prescribing information
Funding
not stated in the source

The page gives no label doses. The cholesterol line is a class statement, not a measured fluoxymesterone effect.

Read the original source
Laboratory study: potent inhibition of human 11-beta-HSD2, no blood pressure measured

Cell study

Fürstenberger C et al. Toxicol Sci. 2012;126(2):353-61. PMID 22273746.

Fluoxymesterone potently inhibited human 11-beta-hydroxysteroid dehydrogenase 2, the enzyme that inactivates cortisol (IC50 60 to 100 nM in lysates; 160 nM in SW-620 cells and 530 nM in MCF-7 cells), and inhibited rodent forms much more weakly. The authors propose that this could let cortisol activate mineralocorticoid receptors and contribute to hypertension. No blood pressure was measured.

Participants / model
Recombinant human enzyme and human cell lines; rodent enzyme comparison
Treatment
In vitro fluoxymesterone exposure
Follow-up
not stated in the source
Study design
Original laboratory study
Funding
not stated in the source

This is a laboratory finding and a hypothesis, not a measured effect on blood pressure in people.

Read the original source

What risks do the label and case reports describe?

The label warns that prolonged high doses of 17-alpha-alkyl androgens have been associated with liver adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

The label warns that prolonged high doses of androgens, principally the 17-alpha-alkyl androgens, have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening, and that cholestatic hepatitis and jaundice may occur. It advises periodic liver function tests.

Other warnings and precautions cover edema with or without heart failure in patients with cardiac, renal or hepatic disease, retention of sodium, chloride and water, polycythemia, virilization in women that may not reverse, and hypercalcemia in breast cancer. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

A pathology series described peliosis hepatis in 12 patients treated with high-dose oxymetholone or fluoxymesterone. Liver failure was the primary cause of death in 3, the lesion was an incidental autopsy finding in 8, and in 1 biopsy-diagnosed case it was absent at autopsy 2 years after the androgen was stopped. The abstract does not separate cases by drug, so the series is class evidence, not a fluoxymesterone-specific rate. In the adjuvant breast cancer trial, virilization was more common with fluoxymesterone.

The liver evidence is class labeling plus case reports that often pool androgens.

HALOTESTIN label, version effective 6 February 2006: uses, warnings, athletic-use statement

FDA prescribing information

DailyMed, U.S. National Library of Medicine. HALOTESTIN (fluoxymesterone) oral tablets, prescribing information, label version effective 6 February 2006. Set ID 09bafc2d-1893-4618-86dc-e9403407cd41.

The label lists replacement therapy in men with primary or hypogonadotropic hypogonadism and delayed puberty, and palliation of androgen-responsive recurrent breast cancer in women 1 to 5 years postmenopausal or with a proven hormone-dependent tumor. The oral half-life is given as about 9.2 hours. Fluoxymesterone is Schedule III under the Anabolic Steroids Control Act, and the label states it has not been shown to be safe and effective for enhancing athletic performance and should not be used for that purpose. It warns that prolonged high doses of androgens, principally the 17-alpha-alkyl androgens, have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening, and that cholestatic hepatitis and jaundice may occur; it advises periodic liver function tests. Other warnings and precautions cover edema with or without heart failure in patients with cardiac, renal or hepatic disease, retention of sodium, chloride and water, polycythemia, virilization in women that may not reverse, hypercalcemia in breast cancer, and a class statement that serum cholesterol may increase during androgen therapy. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

Participants / model
Men with hypogonadism or delayed puberty; women with androgen-responsive recurrent breast cancer; label populations
Treatment
HALOTESTIN oral tablets
Follow-up
Label version effective 6 February 2006
Study design
FDA prescribing information
Funding
not stated in the source

The page gives no label doses. The cholesterol line is a class statement, not a measured fluoxymesterone effect.

Read the original source
Peliosis hepatis: 12 patients on high-dose oral androgens, drugs not separated

Case report

Nadell J et al. Arch Pathol Lab Med. 1977;101(8):405-10. PMID 577673.

A pathology series described peliosis hepatis in 12 patients treated with high-dose oxymetholone or fluoxymesterone. Liver failure was the primary cause of death in 3, the lesion was an incidental autopsy finding in 8, and in 1 biopsy-diagnosed case it was absent at autopsy 2 years after the androgen was stopped. The abstract does not separate cases by drug.

Participants / model
12 patients on high-dose oral androgen therapy
Treatment
Oral oxymetholone or fluoxymesterone, high dose
Follow-up
not stated in the source
Study design
Pathology case series
Funding
not stated in the source

Class-level liver evidence; the abstract does not say which cases involved fluoxymesterone.

Read the original source
Adjuvant trial: 541 women, no gain in relapse-free or overall survival

Randomized controlled trial

Ingle JN et al. Breast Cancer Res Treat. 2006;98(2):217-22. PMID 16538529.

Adding fluoxymesterone did not improve relapse-free survival (HR 0.84, 95% CI 0.64 to 1.10) or overall survival (HR 0.89, 95% CI 0.67 to 1.18) at a median 11.4-year follow-up, and virilization was more common.

Participants / model
541 postmenopausal women with resected ER-positive early breast cancer
Treatment
Oral fluoxymesterone 10 mg twice daily for 1 year added to 5 years of tamoxifen
Follow-up
1 year of fluoxymesterone; median follow-up 11.4 years
Study design
Randomized trial
Funding
not stated in the source

A cancer population; the result does not apply to healthy people.

Read the original source

Why does fluoxymesterone sit in B tier?

A long FDA-approved run and randomized oncology data support the B, but the outcomes are mixed, all US approvals were withdrawn after marketing stopped, and the label carries liver warnings. The grade does not cover the strength and contest claim.

The B reflects a drug with an FDA approval from 1956 and randomized data in breast cancer and dialysis anemia. Added to tamoxifen it lengthened time to progression in metastatic breast cancer without a survival gain, it gave no benefit as adjuvant therapy, and it did less than injected androgens for dialysis anemia. All US approvals were withdrawn after the holders stopped marketing it.

The supplier's strength and contest use is a separate question. No human study of muscle, strength or athletic performance was found, and the label states the drug has not been shown safe and effective for that purpose.

Drugs@FDA: HALOTESTIN approved 15 October 1956, 8 applications, all discontinued

Regulatory record

U.S. Food and Drug Administration. Drugs@FDA application record for NDA 010611 (HALOTESTIN, fluoxymesterone), with related fluoxymesterone applications. Dates read from the openFDA Drugs@FDA records.

FDA approved HALOTESTIN tablets under NDA 010611 (Pharmacia and Upjohn) on 15 October 1956. Drugs@FDA lists 8 fluoxymesterone applications, including the generics ANDROID-F (ANDA 087196, approved 6 July 1981) and Upsher-Smith tablets (ANDA 088342, approved 21 October 1983). Every listed product is marked discontinued.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Approvals from 1956 to 1983
Study design
FDA application records
Funding
not stated in the source

These records give approval dates and product status. Indications come from the product label.

Read the original source
Federal Register: HALOTESTIN approval withdrawn 18 June 2009; Upsher-Smith generic 25 May 2022

Regulatory record

Federal Register, 19 May 2009, notice E9-11628, withdrawal of approval of new drug applications including NDA 10-611 (HALOTESTIN). The 2022 withdrawal of the Upsher-Smith generic (ANDA 088342) is Federal Register notice 2022-08744.

Approval of the HALOTESTIN application (NDA 10-611) was withdrawn effective 18 June 2009, and approval of the Upsher-Smith generic (ANDA 088342, 10 mg) was withdrawn as of 25 May 2022. In both notices the holders had told FDA the products were no longer marketed and asked for withdrawal. Neither notice states a safety finding.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Withdrawals effective 2009 and 2022
Study design
Federal Register notices
Funding
not stated in the source

The withdrawals followed holder requests after marketing stopped. They are not safety findings.

Read the original source
HALOTESTIN label, version effective 6 February 2006: uses, warnings, athletic-use statement

FDA prescribing information

DailyMed, U.S. National Library of Medicine. HALOTESTIN (fluoxymesterone) oral tablets, prescribing information, label version effective 6 February 2006. Set ID 09bafc2d-1893-4618-86dc-e9403407cd41.

The label lists replacement therapy in men with primary or hypogonadotropic hypogonadism and delayed puberty, and palliation of androgen-responsive recurrent breast cancer in women 1 to 5 years postmenopausal or with a proven hormone-dependent tumor. The oral half-life is given as about 9.2 hours. Fluoxymesterone is Schedule III under the Anabolic Steroids Control Act, and the label states it has not been shown to be safe and effective for enhancing athletic performance and should not be used for that purpose. It warns that prolonged high doses of androgens, principally the 17-alpha-alkyl androgens, have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening, and that cholestatic hepatitis and jaundice may occur; it advises periodic liver function tests. Other warnings and precautions cover edema with or without heart failure in patients with cardiac, renal or hepatic disease, retention of sodium, chloride and water, polycythemia, virilization in women that may not reverse, hypercalcemia in breast cancer, and a class statement that serum cholesterol may increase during androgen therapy. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

Participants / model
Men with hypogonadism or delayed puberty; women with androgen-responsive recurrent breast cancer; label populations
Treatment
HALOTESTIN oral tablets
Follow-up
Label version effective 6 February 2006
Study design
FDA prescribing information
Funding
not stated in the source

The page gives no label doses. The cholesterol line is a class statement, not a measured fluoxymesterone effect.

Read the original source
Metastatic breast cancer: 238 women, response 54% versus 42%, time to progression 11.6 versus 6.5 months

Randomized controlled trial

Ingle JN et al. Cancer. 1991;67(4):886-91. PMID 1991261.

Objective responses were 42% (50 of 119) on tamoxifen versus 54% (64 of 119) on tamoxifen plus fluoxymesterone (P = 0.07), and median time to progression was 6.5 versus 11.6 months (P = 0.03). Response duration and survival were similar overall.

Participants / model
238 postmenopausal women with metastatic breast cancer
Treatment
Oral tamoxifen or tamoxifen plus fluoxymesterone (each 10 mg twice daily)
Follow-up
not stated in the source
Study design
Randomized trial
Funding
not stated in the source

A cancer population; the result does not apply to healthy people. Endpoints were objective response, time to progression and survival.

Read the original source
Adjuvant trial: 541 women, no gain in relapse-free or overall survival

Randomized controlled trial

Ingle JN et al. Breast Cancer Res Treat. 2006;98(2):217-22. PMID 16538529.

Adding fluoxymesterone did not improve relapse-free survival (HR 0.84, 95% CI 0.64 to 1.10) or overall survival (HR 0.89, 95% CI 0.67 to 1.18) at a median 11.4-year follow-up, and virilization was more common.

Participants / model
541 postmenopausal women with resected ER-positive early breast cancer
Treatment
Oral fluoxymesterone 10 mg twice daily for 1 year added to 5 years of tamoxifen
Follow-up
1 year of fluoxymesterone; median follow-up 11.4 years
Study design
Randomized trial
Funding
not stated in the source

A cancer population; the result does not apply to healthy people.

Read the original source
Dialysis anemia: oral fluoxymesterone raised hematocrit less than injected androgens

Randomized controlled trial

Neff MS et al. N Engl J Med. 1981;304(15):871-5. PMID 7010161.

Injected nandrolone decanoate and testosterone enanthate raised hematocrit in clearly more patients, and by more, than oral oxymetholone or fluoxymesterone.

Participants / model
Anemic adults on maintenance hemodialysis; 77 completed the first 6-month period
Treatment
Up to three androgens in successive 6-month periods, among oral fluoxymesterone, oral oxymetholone, injected nandrolone decanoate and injected testosterone enanthate
Follow-up
6-month periods
Study design
Randomized trial
Funding
not stated in the source

A dialysis population; hematocrit response, not strength or muscle, was the endpoint.

Read the original source
PubMed search, 9 October 2026: 53 records, none on muscle or strength in healthy people

PubMed search record

PubMed search run on 9 October 2026: fluoxymesterone AND (muscle OR strength OR lean body mass OR body composition OR athletes OR athletic OR performance OR nitrogen balance). 53 records returned.

The search returned 53 records. By title, none tested muscle mass, strength or athletic performance in healthy people or athletes; they covered breast and prostate cancer, anemia, doping-control metabolism and detection, rodent and cell studies, and a 1989 case report in Kennedy-Alter-Sung syndrome. A 1974 pharmacologic evaluation in normal men sat outside this search and has no abstract, so its endpoints are unknown. The strength and contest use has no trial behind it among these records.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Search run on 9 October 2026
Study design
Literature search
Funding
not stated in the source

A search result shows what PubMed returned on that date. It is not proof that no unindexed study exists.

Read the original source

Studies and sources

Drugs@FDA: HALOTESTIN approved 15 October 1956, 8 applications, all discontinued

Regulatory record

U.S. Food and Drug Administration. Drugs@FDA application record for NDA 010611 (HALOTESTIN, fluoxymesterone), with related fluoxymesterone applications. Dates read from the openFDA Drugs@FDA records.

FDA approved HALOTESTIN tablets under NDA 010611 (Pharmacia and Upjohn) on 15 October 1956. Drugs@FDA lists 8 fluoxymesterone applications, including the generics ANDROID-F (ANDA 087196, approved 6 July 1981) and Upsher-Smith tablets (ANDA 088342, approved 21 October 1983). Every listed product is marked discontinued.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Approvals from 1956 to 1983
Study design
FDA application records
Funding
not stated in the source

These records give approval dates and product status. Indications come from the product label.

Read the original source
Federal Register: HALOTESTIN approval withdrawn 18 June 2009; Upsher-Smith generic 25 May 2022

Regulatory record

Federal Register, 19 May 2009, notice E9-11628, withdrawal of approval of new drug applications including NDA 10-611 (HALOTESTIN). The 2022 withdrawal of the Upsher-Smith generic (ANDA 088342) is Federal Register notice 2022-08744.

Approval of the HALOTESTIN application (NDA 10-611) was withdrawn effective 18 June 2009, and approval of the Upsher-Smith generic (ANDA 088342, 10 mg) was withdrawn as of 25 May 2022. In both notices the holders had told FDA the products were no longer marketed and asked for withdrawal. Neither notice states a safety finding.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Withdrawals effective 2009 and 2022
Study design
Federal Register notices
Funding
not stated in the source

The withdrawals followed holder requests after marketing stopped. They are not safety findings.

Read the original source
HALOTESTIN label, version effective 6 February 2006: uses, warnings, athletic-use statement

FDA prescribing information

DailyMed, U.S. National Library of Medicine. HALOTESTIN (fluoxymesterone) oral tablets, prescribing information, label version effective 6 February 2006. Set ID 09bafc2d-1893-4618-86dc-e9403407cd41.

The label lists replacement therapy in men with primary or hypogonadotropic hypogonadism and delayed puberty, and palliation of androgen-responsive recurrent breast cancer in women 1 to 5 years postmenopausal or with a proven hormone-dependent tumor. The oral half-life is given as about 9.2 hours. Fluoxymesterone is Schedule III under the Anabolic Steroids Control Act, and the label states it has not been shown to be safe and effective for enhancing athletic performance and should not be used for that purpose. It warns that prolonged high doses of androgens, principally the 17-alpha-alkyl androgens, have been associated with hepatic adenomas, hepatocellular carcinoma and peliosis hepatis, all potentially life-threatening, and that cholestatic hepatitis and jaundice may occur; it advises periodic liver function tests. Other warnings and precautions cover edema with or without heart failure in patients with cardiac, renal or hepatic disease, retention of sodium, chloride and water, polycythemia, virilization in women that may not reverse, hypercalcemia in breast cancer, and a class statement that serum cholesterol may increase during androgen therapy. It is contraindicated in serious cardiac, hepatic or renal disease, male breast or prostate cancer, and pregnancy.

Participants / model
Men with hypogonadism or delayed puberty; women with androgen-responsive recurrent breast cancer; label populations
Treatment
HALOTESTIN oral tablets
Follow-up
Label version effective 6 February 2006
Study design
FDA prescribing information
Funding
not stated in the source

The page gives no label doses. The cholesterol line is a class statement, not a measured fluoxymesterone effect.

Read the original source
Metastatic breast cancer: 238 women, response 54% versus 42%, time to progression 11.6 versus 6.5 months

Randomized controlled trial

Ingle JN et al. Cancer. 1991;67(4):886-91. PMID 1991261.

Objective responses were 42% (50 of 119) on tamoxifen versus 54% (64 of 119) on tamoxifen plus fluoxymesterone (P = 0.07), and median time to progression was 6.5 versus 11.6 months (P = 0.03). Response duration and survival were similar overall.

Participants / model
238 postmenopausal women with metastatic breast cancer
Treatment
Oral tamoxifen or tamoxifen plus fluoxymesterone (each 10 mg twice daily)
Follow-up
not stated in the source
Study design
Randomized trial
Funding
not stated in the source

A cancer population; the result does not apply to healthy people. Endpoints were objective response, time to progression and survival.

Read the original source
Adjuvant trial: 541 women, no gain in relapse-free or overall survival

Randomized controlled trial

Ingle JN et al. Breast Cancer Res Treat. 2006;98(2):217-22. PMID 16538529.

Adding fluoxymesterone did not improve relapse-free survival (HR 0.84, 95% CI 0.64 to 1.10) or overall survival (HR 0.89, 95% CI 0.67 to 1.18) at a median 11.4-year follow-up, and virilization was more common.

Participants / model
541 postmenopausal women with resected ER-positive early breast cancer
Treatment
Oral fluoxymesterone 10 mg twice daily for 1 year added to 5 years of tamoxifen
Follow-up
1 year of fluoxymesterone; median follow-up 11.4 years
Study design
Randomized trial
Funding
not stated in the source

A cancer population; the result does not apply to healthy people.

Read the original source
Dialysis anemia: oral fluoxymesterone raised hematocrit less than injected androgens

Randomized controlled trial

Neff MS et al. N Engl J Med. 1981;304(15):871-5. PMID 7010161.

Injected nandrolone decanoate and testosterone enanthate raised hematocrit in clearly more patients, and by more, than oral oxymetholone or fluoxymesterone.

Participants / model
Anemic adults on maintenance hemodialysis; 77 completed the first 6-month period
Treatment
Up to three androgens in successive 6-month periods, among oral fluoxymesterone, oral oxymetholone, injected nandrolone decanoate and injected testosterone enanthate
Follow-up
6-month periods
Study design
Randomized trial
Funding
not stated in the source

A dialysis population; hematocrit response, not strength or muscle, was the endpoint.

Read the original source
Peliosis hepatis: 12 patients on high-dose oral androgens, drugs not separated

Case report

Nadell J et al. Arch Pathol Lab Med. 1977;101(8):405-10. PMID 577673.

A pathology series described peliosis hepatis in 12 patients treated with high-dose oxymetholone or fluoxymesterone. Liver failure was the primary cause of death in 3, the lesion was an incidental autopsy finding in 8, and in 1 biopsy-diagnosed case it was absent at autopsy 2 years after the androgen was stopped. The abstract does not separate cases by drug.

Participants / model
12 patients on high-dose oral androgen therapy
Treatment
Oral oxymetholone or fluoxymesterone, high dose
Follow-up
not stated in the source
Study design
Pathology case series
Funding
not stated in the source

Class-level liver evidence; the abstract does not say which cases involved fluoxymesterone.

Read the original source
Laboratory study: potent inhibition of human 11-beta-HSD2, no blood pressure measured

Cell study

Fürstenberger C et al. Toxicol Sci. 2012;126(2):353-61. PMID 22273746.

Fluoxymesterone potently inhibited human 11-beta-hydroxysteroid dehydrogenase 2, the enzyme that inactivates cortisol (IC50 60 to 100 nM in lysates; 160 nM in SW-620 cells and 530 nM in MCF-7 cells), and inhibited rodent forms much more weakly. The authors propose that this could let cortisol activate mineralocorticoid receptors and contribute to hypertension. No blood pressure was measured.

Participants / model
Recombinant human enzyme and human cell lines; rodent enzyme comparison
Treatment
In vitro fluoxymesterone exposure
Follow-up
not stated in the source
Study design
Original laboratory study
Funding
not stated in the source

This is a laboratory finding and a hypothesis, not a measured effect on blood pressure in people.

Read the original source
6-person crossover PK study: half-life 2.0 hours, conflicts with the label's 9.2 hours

Human study

Capponi VJ et al. J Pharm Sci. 1985;74(3):308-11. PMID 4009439.

In a 6-person crossover bioavailability study of 10 mg tablets taken orally or buccally, Cmax ranged from 40 to 150 ng/mL with tmax of 1 to 2 hours, and the harmonic mean half-life was 2.0 hours. Oral Cmax and AUC were 80% and 76% of the buccal values. This half-life is much shorter than the label's 9.2 hours.

Participants / model
6 subjects (health status not stated in the abstract)
Treatment
Single 10 mg tablet, oral or buccal
Follow-up
Single-dose crossover
Study design
Crossover bioavailability study
Funding
not stated in the source

The 2.0-hour half-life conflicts with the label's 9.2 hours, and the sources do not reconcile the two.

Read the original source
PubChem CID 6446: C20H29FO3, 336.4 g/mol

Chemical identity record

National Library of Medicine. PubChem compound record CID 6446 (fluoxymesterone).

Fluoxymesterone: PubChem CID 6446, C20H29FO3, 336.4 g/mol, CAS 76-43-7, a 9-alpha-fluoro, 11-beta-hydroxy, 17-alpha-methyl testosterone derivative (label molecular weight 336.45). No salt or ester forms are involved.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Identity record only; it says nothing about efficacy or safety. Because every US approval has been withdrawn, any product sold now is not an FDA-approved fluoxymesterone product.

Read the original source

Why is Fluoxymesterone in B tier?

B fits a drug with a long FDA-approved run (HALOTESTIN from 1956) and randomized oncology data whose outcomes are mixed: added to tamoxifen it lengthened time to progression in metastatic breast cancer without a survival gain, it gave no benefit as adjuvant therapy, and it did less than injected androgens for dialysis anemia. All US approvals were withdrawn after marketing stopped, and the label carries liver warnings. The grade does not cover strength or contest use, which has no human study behind it in the records found.