Calusterone
Calusterone (7beta,17alpha-dimethyltestosterone) is an orally active 17-alpha-methylated androgen that was investigated as an antineoplastic agent for advanced breast cancer in the 1970s under the brand Methosarb. It is a moderately anabolic, weakly aromatising oral with documented human clinical exposure in oncology, alongside the hepatotoxicity typical of methylated orals.
01 Overview
Calusterone was developed and studied as a therapeutic androgen for hormone-responsive metastatic breast cancer, where high-dose androgens were used to suppress tumour growth. This gives it a comparatively real (if dated) human clinical record relative to designer orals.
Structurally it is a 7-beta,17-alpha-dimethyl testosterone. It is orally active due to the 17-alpha methyl and shows a moderate anabolic profile. Because it was used at high oncologic doses, virilisation and hepatic effects were documented; it is no longer marketed.
02 Mechanism
Androgen-receptor agonist; 17-alpha-methyl group confers oral activity; 7-beta-methyl substitution modulates metabolism and reduces estrogenic conversion.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Historical oncology | 50–200 mg/day | Oral | High-dose breast-cancer therapy; not a performance dose. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Anti-tumour (hormone-responsive breast cancer)Used to induce remissions in metastatic breast cancer. | objective responses in trials | Clinical | |
| Lean mass/anabolic effectAnabolic androgenic effect at therapeutic doses. | moderate | Observational |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| VirilisationHirsutism, voice deepening in female patients at high doses. | Moderate | Common at oncologic doses | Clinical | |
| HepatotoxicityRaised transaminases and cholestasis with methylated oral use. | Moderate | Common | Clinical | |
| HPTA suppressionSuppresses endogenous gonadotropins and testosterone. | Severe | Universal in men | Clinical |