Testosterone, Total, Women, Children, and Hypogonadal Males, LC/MS-MS

Testosterone is a hormone found in both males and females that plays important roles in sexual development, energy, bone strength, and muscle mass. This specialized blood test uses a highly accurate laboratory technique called LC/MS-MS to measure testosterone precisely in people who naturally have lower levels—such as women, children, and men with low testosterone. Standard testosterone tests are not accurate enough at these low levels, which is why this more sensitive method is used. Your doctor may order this test to investigate symptoms like irregular periods, unusual hair growth, delayed puberty, or low energy and libido. Results are always interpreted alongside your age, sex, stage of development, and other hormone levels.

When elevated: Elevated testosterone in women may suggest androgen excess disorders such as PCOS, CAH, or androgen-secreting adrenal or ovarian neoplasms, and is associated with hirsutism, acne, menstrual irregularity, and virilization. In prepubertal children, elevated testosterone may indicate precocious puberty, CAH, or a gonadal or adrenal tumor. In hypogonadal males on testosterone replacement therapy, supratherapeutic levels may reflect over-replacement and warrant dose adjustment. When low: Low testosterone in women may be associated with diminished libido, fatigue, reduced bone density, and impaired well-being, though clinical significance remains debated and no consensus diagnostic threshold exists. In children, low testosterone relative to pubertal stage may indicate hypogonadotropic or hypergonadotropic hypogonadism, constitutional delay of growth and puberty, or chronic systemic illness. In hypogonadal males, persistently low levels confirm inadequate endogenous production or subtherapeutic replacement and may be associated with symptoms including fatigue, decreased libido, erectile dysfunction, and reduced muscle mass.

Testosterone supports muscle protein synthesis, bone density, and recovery—key factors in athletic performance and training adaptation. This gold-standard test is especially useful for female athletes and younger males to establish baseline androgen status and detect training-related hormonal shifts; however, single measurements have limited predictive value for performance, and results should be interpreted alongside clinical context and other markers.