methyltestosterone
Regulatory sources consulted
Approved indications
- Treatment of moderate or severe menopausal vasomotor symptoms not improved by estrogen alone.
Contraindications
Absolute
- Undiagnosed genital bleeding, known or suspected breast cancer, or estrogen-dependent neoplasia.
- Current or prior deep-vein thrombosis, pulmonary embolism, arterial thromboembolic disease, or thrombophilia.
- Liver disease, pregnancy, or hypersensitivity to components.
Clinical warnings
- Boxed warning · The combination retains estrogen-related risks of endometrial and breast cancer, stroke, venous thrombosis, and pulmonary embolism; use the lowest effective dose and duration. — DailyMed, set_id 2157d248-f6f5-4cb4-806d-d2e8eec6a8db
- Major warning · Methyltestosterone may cause virilization, cholestatic jaundice, peliosis hepatis, or liver tumor; stop for signs of virilization or liver dysfunction. — DailyMed, set_id 2157d248-f6f5-4cb4-806d-d2e8eec6a8db
Drug interactions
- HighOral anticoagulants
Mechanism: Androgens may increase the anticoagulant response.
Recommendation: Closely monitor coagulation and adjust the anticoagulant according to response.
DailyMed, set_id 2157d248-f6f5-4cb4-806d-d2e8eec6a8dbhttps://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2157d248-f6f5-4cb4-806d-d2e8eec6a8db
- ModerateInsulin
Mechanism: The metabolic effects of androgens may decrease blood glucose and insulin requirements in patients with diabetes.
Recommendation: Monitor blood glucose and adjust insulin with the clinical team when needed.
DailyMed, set_id 2157d248-f6f5-4cb4-806d-d2e8eec6a8dbhttps://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2157d248-f6f5-4cb4-806d-d2e8eec6a8db
Adverse events
Common (≥1%)
Headache · Breast pain · Nausea · Acne or hirsutism · Voice changes · Uterine bleeding
Rare but serious
Thrombosis or embolism · Peliosis hepatis or liver tumor · Irreversible virilization
Pregnancy and lactation
Contraindicated during pregnancy and in breastfeeding mothers because of the possibility of masculinization of a female fetus or breastfed infant.
Recent literature (PubMed)
Severely skewed sex ratios in zebrafish stocks can pose significant hurdles for line propagation and sperm cryopreservation. To overcome female-biased sex ratios in stocks derived from imported sperm samples, the Zebrafish International Resource Center has implemented routine supplementation of larval food with 17α-methyltestosterone to skew gonadal sex differentiation toward masculinization. Resulting stocks averaged 80% males.
Testosterone deficiency is a clinical disorder due to either failure of the testes to produce testosterone or failure of the hypothalamus or pituitary to produce sufficient gonadotropins. Previous formulations of oral testosterone therapy, particularly methyltestosterone, have been associated with adverse liver effects. Many different routes of testosterone delivery have been developed, each with their own administrative benefits and challenges. Newer formulations of oral testosterone undecanoate (TU) provide a convenient administration option, although their use has been limited by hepatotoxicity concerns based on older methyltestosterone data, and prescribing physicians may still be concerned about adverse liver effects. In this review, we discuss the history of oral testosterone development, clarify the mechanism of action of oral TU, and describe the relevant liver safety findings. Relevant literature was allocated to present a review on the history of oral TU development and the mechanism of action of oral TU. We pooled data from individual studies of oral TU products to present a safety summary. Overall, safety results from studies of the newer formulations of oral TU showed that increased liver function test values are not generally associated with oral TU formulations and that no clinically significant liver toxicities were noted in clinical trials of oral TU. Continued research into the safety of oral TU will contribute to a better understanding of the potential risks in patients receiving this therapy, an outcome that highlights the importance of providing patient education and reassurance regarding oral TU safety. Nonsyndromic 46,XX testicular disorders/differences of sex development (DSD) are characterized by: the presence of a 46,XX karyotype; external genitalia ranging from typical male to ambiguous; two testicles; azoospermia; absence of müllerian structures; and absence of other syndromic features, such as congenital anomalies outside of the genitour
This study investigated the individual and combined effects of Polystyrene microplastics (PS) and 17α-methyltestosterone (MT) on the gill and liver of Gobiocypris rarus.Exposure to PS (0.5 mg/L) and MT (50 ng/L) induced significant histopathological alterations and immunotoxicity. Tissues exhibited inflammatory infiltration, nuclear dissolution, and cytoplasmic vacuolation, with the most severe lesions observed under combined exposure. Gene expression analysis revealed significant upregulation of immune and oxidative stress-related genes, including caspase 6 (CASP6), interleukin-1 receptor type I (IL-1RI), NADPH oxidase 1 (NOX1), Toll-like receptor 2 (TLR-2), and C-C motif chemokine receptor 7 (CCR7), while antioxidant enzyme activities and malondialdehyde (MDA) levels were disrupted, indicating enhanced oxidative stress. Transcriptomic analysis of gills further revealed enrichment of ECM-receptor interaction, cell adhesion molecules, and leukocyte transendothelial migration pathways, suggesting that PS and MT may compromise immune function by interfering with extracellular matrix-related signaling, thereby exacerbating tissue damage and posing combined ecological risks in aquatic organisms.