Normal Testosterone Levels in Women
The American College of Physicians recommends against routine testosterone measurement in women outside research settings because no validated reference ranges exist for what constitutes optimal testosterone levels in women, making any measured value clinically meaningless. 1, 2
Why Testosterone Testing is Not Recommended in Women
- Current clinical guidelines explicitly state that there are no established optimal testosterone levels or proven benefits for testosterone replacement therapy in women, whether perimenopausal or postmenopausal 1, 2
- The lack of validated reference ranges means that even if you obtain a testosterone level, you cannot reliably interpret whether it is "normal" or "abnormal" for clinical decision-making 1, 2
Research-Based Reference Values (For Context Only)
While guidelines discourage routine testing, research studies have established reference ranges using mass spectrometry in healthy women:
Premenopausal Women (Age 30)
- Total testosterone: 15-46 ng/dL (0.52-1.60 nmol/L) - 5th to 95th percentile 3
- Free testosterone: 1.2-6.4 pg/mL (4.16-22.2 pmol/L) 3
- Bioavailable testosterone: 1.12-7.62 ng/dL 3
Age-Related Decline
- Testosterone levels decline by approximately 50% from the early 20s to mid-40s in normal women 4
- Total testosterone reference range across ages 20-80 years: 0.35-1.97 nmol/L (approximately 10-57 ng/dL) 5
- Testosterone reaches its lowest levels following menopause, with nadir around age 60 6
Abnormal Threshold (Specific Context)
- For women with epilepsy being evaluated for reproductive dysfunction, testosterone >2.5 nmol/L (approximately 72 ng/dL) measured on cycle days 3-6 is considered abnormal 1
What to Do Instead of Measuring Testosterone
When a woman presents with symptoms potentially attributable to androgen deficiency (fatigue, decreased libido, diminished well-being), the appropriate workup excludes other causes rather than measuring testosterone: 1, 2
- Check thyroid function: TSH and free T4 1
- Screen for depression using validated instruments 1
- Review medications that may cause similar symptoms 1
- Assess for hyperprolactinemia and other endocrine disorders 1
Critical Caveats
- Laboratory reference values for testosterone vary widely between facilities, with low reference values ranging from 130 to 450 ng/dL in some studies (a 350% difference), though these were primarily male-focused ranges 7
- Most testosterone assays lack adequate sensitivity and reliability in the low concentration range typical of women 4, 5
- If testosterone measurement is absolutely necessary for research purposes, it requires a sensitive assay for total testosterone plus sex hormone-binding globulin measurement to calculate free testosterone 4