Normal Testosterone Ranges in Adult Women
In healthy adult women, normal serum testosterone ranges from approximately 15–46 ng/dL (0.52–1.60 nmol/L) for total testosterone and 1.2–6.4 pg/mL (4.16–22.2 pmol/L) for free testosterone, with values declining modestly with age and showing minimal clinically significant variation across the menstrual cycle. 1
Reference Ranges by Measurement Type
Total Testosterone
- Premenopausal women (age 30): 15–46 ng/dL (520–1,595 pmol/L or 0.52–1.60 nmol/L) using the 5th to 95th percentile range 1
- Alternative reference range (premenopausal): 0.30–1.69 nmol/L (8.7–48.7 ng/dL) when measured by highly accurate isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) 2
- Broader population estimate: 0.4–2.0 nmol/L (11.5–57.7 ng/dL) represents the typical female range, which is four- to fivefold lower than the male lower limit 3
Free Testosterone
- Premenopausal women (age 30): 1.2–6.4 pg/mL (4.16–22.2 pmol/L) measured by equilibrium dialysis 1
- Calculated free testosterone: 1.3–5.6 pg/mL (4.5–19.4 pmol/L) 1
Bioavailable Testosterone
- Premenopausal women (age 30): 1.12–7.62 ng/dL (38.8–264.2 pmol/L) 1
Sex Hormone-Binding Globulin (SHBG)
- Premenopausal women: 18–86 nmol/L, remaining relatively stable across age ranges 1
Age-Related Changes
Testosterone concentrations decline progressively with age in women, while SHBG levels remain relatively constant. 1 Postmenopausal women demonstrate significantly lower total testosterone, free testosterone, and SHBG compared to premenopausal women, with concomitant declines in estradiol and estrone. 4
Menstrual Cycle Variation
Testosterone shows a statistically significant but clinically minor elevation at mid-cycle (around ovulation), with levels remaining slightly elevated during the mid-luteal phase. 1, 4 However, this mid-cycle peak is small relative to overall day-to-day variability and is not consistently discernible in every individual. 2 The increase is modest enough that reference ranges can be applied regardless of menstrual cycle timing when the sample is obtained. 1
- Early follicular phase: baseline levels
- Mid-cycle (ovulation): peak levels of total testosterone, free testosterone, estradiol, and estrone 4
- Mid-luteal phase: levels remain elevated compared to early follicular phase 4
- DHT (dihydrotestosterone): does not change significantly across the menstrual cycle 4
Pathological Elevations
Testosterone levels above 2.5 nmol/L (72 ng/dL) are considered abnormal in women and warrant investigation for conditions such as polycystic ovary syndrome (PCOS), valproate use, or non-classical adrenal hyperplasia. 5 Women with PCOS or congenital adrenal hyperplasia typically have testosterone levels above the normal female range but still well below the normal male range (male range: 8.8–30.9 nmol/L or 254–891 ng/dL). 3
Measurement Considerations
Accurate testosterone measurement in women requires validated assays with sufficient sensitivity at low concentrations, as many direct immunoassays perform poorly in the female range. 1, 4 Liquid chromatography-tandem mass spectrometry (LC-MS/MS) provides more accurate and precise measurements than traditional immunoassays, typically yielding lower overall values. 4, 2 Second-generation automated immunoassays show acceptable correlation with LC-MS/MS methods but may exhibit a persistent positive bias. 2
Clinical Pitfalls to Avoid
- Do not rely on a single testosterone measurement to assess overall testosterone status, as day-to-day variation exceeds menstrual cycle-related changes 2
- Do not assume mid-cycle timing is necessary for diagnostic accuracy; the small mid-cycle elevation is not clinically relevant for most assessments 1, 2
- Avoid using direct immunoassays when precision at low concentrations is critical; request LC-MS/MS or equilibrium dialysis methods for free testosterone 1, 4
- Always measure SHBG when interpreting total testosterone, as it affects the bioavailable fraction 1