The testosterone test, when measured by LC/MS, produces an accurate and sensitive quantitation of testosterone in circulation.
Measurement of total testosterone in women should be performed by a sensitive liquid chromatography/tandem mass spectrometry (LC/MS)-based assay.
Immunoassay-based testosterone tests perform best at higher concentrations of testosterone and therefore work well for those with testosterone levels in the adult-male range.
What does the test tell me?
This test, when measured by LC/MS, produces an accurate and sensitive quantitation of testosterone in circulation. If above the sex- and age-appropriate reference interval, this may be an indicator of androgen excess, though moderate androgen excess may not be detected with a total testosterone measurement alone.
When should I order this test?
Testosterone by LC/MS in women should be used to evaluate women with symptoms of androgen excess (e.g., hirsutism, oligo amenorrhea, virilization, or infertility) or androgen deficiency (decreased libido). However, FDA-approved testosterone formulations for women are unavailable at this time.
When should I NOT order this test?
Do not order testosterone by immunoassay on women and children.
How should I interpret the result?
Total testosterone in women should be interpreted in light of sex- and age-appropriate reference intervals. Values above or below the reference interval likely indicate androgen excess or deficiency, respectively.
Is the test result in diagnostic/confirmatory of the condition? If not, is there a diagnostic/confirmatory test?
Mild to moderate testosterone excess should not be excluded based solely on total testosterone within the reference interval. Free and/or bioavailable testosterone tests should be used to confirm. Similarly, low total testosterone should be verified with free and/or bioavailable testosterone.
Are there factors that can affect the lab result?
Testosterone is subject to diurnal variation and is highest in the morning to early afternoon and declines thereafter. It is best to collect the sample between 6-10 am, if possible.
Are there considerations for special populations?
Children also have low circulating testosterone and therefore require testing by LC/MS, similar to women.
What other test(s) might be indicated?
Free and bioavailable testosterone may be useful in cases of mild testosterone abnormalities. Luteinizing hormone (LH) and/or follicle-stimulating hormone (FSH) may be also useful for elucidating the cause of androgen abnormalities.
Be sure to freely contact our qualified medical experts for any concerns.