Female Pattern Hair Loss is Common in Young Women, Even with Normal Androgen Levels
Female pattern hair loss (FPHL) is very common in young women and frequently occurs with normal androgen levels—your patient's borderline-elevated DHEA-S of 35 and free testosterone of 2.0 do NOT exclude FPHL and may actually represent normal values in many women with this condition. 1
The Critical Disconnect Between Androgens and FPHL
The 2019 Androgen Excess and PCOS Society guidelines fundamentally clarify this issue: most women with FPHL have completely normal circulating androgen concentrations 1. The evidence shows:
- Isolated FPHL should NOT be considered a sign of hyperandrogenism when androgen levels are normal 1
- FPHL occurs even in women with total absence of circulating androgens, androgen receptor deficiency, or lack of postpubertal androgenization 1
- The relationship between hair loss and androgen excess in women is "neither consistent nor clear" 1
Your Patient's Laboratory Values
Without knowing the specific reference ranges for your laboratory, these values appear borderline at most. Research demonstrates:
- In one study of 106 women with FPHL, only 6.8% had elevated free testosterone 2
- Another study found serum testosterone and DHEA-S were within normal limits in nearly all adolescent patients with androgenetic alopecia 3
- The majority of affected women show "normal circulating androgen concentrations and an absence of other androgen-related signs or symptoms" 1
Prevalence and Clinical Context
FPHL is extremely common in women:
- It represents the most common cause of hair loss in adult women 4, 5
- Hair loss in women is described as "common" with FPHL being a "particularly common subtype" 1
- Prevalence increases with advancing age 4
Important Clinical Patterns
The guidelines specify two typical patterns 1:
- Centrifugal expansion in the mid-scalp
- Frontal accentuation or "Christmas tree" pattern
- Frontal hairline is generally well preserved
Diagnostic Approach for Your Patient
The diagnosis is primarily clinical 1. According to guidelines, you should:
- Perform careful medical history and physical examination including scalp evaluation 1
- Assess for signs of hyperandrogenism (hirsutism, acne, menstrual irregularities) 1
- Consider dermatoscopic examination or scalp biopsy if diagnosis is uncertain 1
Laboratory Evaluation
The guidelines mandate androgen assessment in all FPHL patients 1, but emphasize:
- Measure total testosterone using high-quality assay (LC/MS preferred) 1
- Measure free testosterone using equilibrium dialysis, ultracentrifugation, or calculated from SHBG 1
- Optional but recommended: vitamin D, iron studies, zinc, thyroid profile, prolactin 1
Recent research (2026) suggests 3α-androstanediol glucuronide (3α-diol G) may be a superior marker of peripheral hyperandrogenism in FPHL, showing 82% sensitivity and 73% specificity, and correlating with clinical severity 6. This marker was significantly elevated in FPHL patients even when other androgens were normal.
Critical Pitfalls to Avoid
- Do not assume normal androgens exclude FPHL—this is the most common misconception 1
- Do not assume borderline androgens indicate causation—one study found 40% of patients reported hyperandrogenic symptoms, yet hormone tests showed no significant abnormalities 2
- Do not delay treatment waiting for "abnormal" labs—the condition is progressive and early treatment is more effective 4
Treatment Implications
Start treatment with topical minoxidil 5% regardless of androgen levels 1. Add 5α-reductase inhibitors or antiandrogens only when:
- Severe hair loss is present, OR
- True hyperandrogenism is documented 1
Your patient's borderline values alone do not mandate antiandrogen therapy unless accompanied by other clinical signs of androgen excess or severe hair loss.