What is the appropriate evaluation and management plan for a woman with female‑pattern androgenetic alopecia, including laboratory work‑up and pharmacologic therapy?

Treatment of Female Pattern Hair Loss (Androgenetic Alopecia)

Topical minoxidil 2% solution applied twice daily is the first-line treatment for women with androgenetic alopecia, and it must be continued indefinitely to maintain results. 1, 2

Initial Evaluation and Diagnosis

Clinical Assessment

• Examine the scalp for diffuse thinning over the central/parietal regions with preservation of the frontal hairline—this pattern is diagnostic of female androgenetic alopecia and distinguishes it from alopecia areata (which presents with discrete patches). 1, 3

• Use dermoscopy to assess for hair follicle miniaturization, which confirms the diagnosis and eliminates the need for scalp biopsy in most cases. 1

• Document baseline severity using standardized photographs from consistent angles, as this enables objective monitoring of treatment response over time. 2, 4

Laboratory Work-Up

Laboratory testing is only indicated when signs of androgen excess are present—specifically hirsutism, severe cystic acne, irregular menses, or virilization. 1, 3

When hormonal evaluation is warranted, order:

• Total testosterone, free testosterone, and sex hormone-binding globulin (SHBG) to assess for hyperandrogenism 1
• TSH and free T4 to exclude thyroid disease, a common reversible cause of hair loss 1
• Serum ferritin (optimal level ≥60 ng/mL for hair growth), vitamin D, and zinc if nutritional deficiency is suspected 1

Do not order extensive autoimmune panels or routine hormonal testing in women with classic androgenetic alopecia and no signs of androgen excess—this represents unnecessary testing that does not alter management. 1

First-Line Pharmacologic Treatment

Topical Minoxidil Monotherapy

• Prescribe minoxidil 2% solution, 1 mL applied to the affected scalp twice daily as initial therapy for all women with female pattern hair loss. 1, 2, 3

• Counsel patients that minoxidil arrests progression rather than stimulates dramatic regrowth, and that visible improvement requires 6–12 months of consistent use. 1, 2

• Emphasize that discontinuation will result in loss of all treatment gains within 3–6 months, so lifelong therapy is required to maintain results. 2, 4

• Monitor treatment response at 6 and 12 months using standardized photographs, patient self-assessment, and clinical examination for increased hair density and shaft diameter. 2, 4

Second-Line Treatment: Adding Platelet-Rich Plasma (PRP)

For women with suboptimal response to minoxidil monotherapy after 12 months, add PRP injections to the treatment regimen. 2, 4

PRP Treatment Protocol

• Use the manual double-spin centrifugation method to achieve a platelet concentration of 1.0–1.5 million platelets per microliter—higher concentrations correlate with greater improvements in hair density and follicle diameter. 2, 4

• Do not activate the PRP, as nonactivated PRP demonstrates 31% greater improvement in hair density compared to activated preparations. 2

• Administer 5–7 mL of PRP per session, injecting 0.05–0.1 mL/cm² at 1-cm intervals, at a 90-degree angle to a depth of 2–4 mm, using 30-gauge × 4-mm needles to minimize discomfort. 2, 4

• Apply pharmaceutical-grade topical anesthetic cream 30–60 minutes before injection because PRP injections cause significant pain. 2, 4

• Schedule 3–5 treatment sessions spaced 1 month apart during the initial treatment phase, then maintain with 1 session every 6 months indefinitely. 2, 4

Expected Outcomes with Combination Therapy

• Combination therapy (PRP plus minoxidil 5%) achieves a 57% median increase in terminal hair density versus 48% with minoxidil alone at 32 weeks. 2

• 83% of patients achieve a negative hair pull test (indicating reduced hair fragility) after combination treatment. 2

• A 25% improvement in hair density at 2 months predicts sustained response at 6 months, allowing early identification of responders. 2, 4

Alternative and Adjunctive Options

Low-Level Laser Therapy (LLLT)

• FDA-cleared 655-nm laser devices applied three times per week provide an additional treatment option for women who prefer non-pharmacologic therapy or wish to augment minoxidil. 2

• Like minoxidil, LLLT requires continuous indefinite use to maintain hair regrowth, and abrupt cessation results in loss of gains within months. 2

Antiandrogen Therapy (For Hyperandrogenic Women Only)

Reserve oral antiandrogens for women with documented androgen excess (elevated testosterone, DHEA-S, or clinical signs of hyperandrogenism). 5, 6, 7

• Spironolactone 100–200 mg daily or cyproterone acetate 50–100 mg daily (if available) can be added to topical minoxidil in hyperandrogenic women. 5, 6, 7

• In one study, 88% of women receiving oral antiandrogens experienced stabilization or improvement of hair loss, though placebo-controlled data are limited. 7

• Do not use finasteride 1 mg daily in premenopausal women—this dose is ineffective for female pattern hair loss, though higher doses (2.5–5 mg daily) show benefit in postmenopausal women in small studies. 5, 6

Critical Pitfalls to Avoid

• Failing to counsel patients about the lifelong nature of treatment—stopping minoxidil or LLLT results in rapid reversal of all gains, leading to patient disappointment and loss of trust. 2, 4

• Using inadequate PRP technique—low platelet concentration, insufficient injection volume, or infrequent treatment sessions lead to treatment failure. 2, 4

• Ordering extensive hormonal panels in women with classic androgenetic alopecia and no signs of androgen excess—this wastes resources and does not change management. 1, 3

• Expecting dramatic regrowth rather than stabilization—the realistic goal of therapy is to slow or halt progression, not to restore full density, so manage patient expectations accordingly. 1, 2

• Insufficient treatment duration before declaring failure—maximum response with PRP typically requires 6 months, and some patients need extended therapy beyond the initial 6-month period. 2