Evidence‑Based Management of Vertex Hair Loss in Adult Women

1. First‑line Topical Therapy

Topical minoxidil 5 % is the only hair‑loss treatment supported by high‑level evidence (Level B) for both telogen effluvium and female pattern hair loss. The recommendation is based on guideline data from the Journal of Clinical Endocrinology & Metabolism (2019) 2.
Pharmacologic actions: minoxidil accelerates the telogen‑to‑anagen transition, prolongs the anagen phase, and converts miniaturized follicles into terminal hairs, benefiting both telogen effluvium and androgenetic alopecia. 2
Formulation choice: a 5 % foam applied once daily provides efficacy equivalent to a 5 % solution applied twice daily, with superior patient adherence and fewer scalp‑related side effects. 2

Paradoxical shedding (weeks 2–8): an early increase in hair shedding is a predictable sign of drug activity; discontinuation during this phase markedly reduces treatment success. 1
Timing of efficacy assessment: clinical improvement generally requires ≥ 6 months, with optimal outcomes often observed after 12 months of continuous use. 3
Common adverse effects: scalp pruritus and flaking (more frequent with propylene‑glycol‑containing solutions) and facial hypertrichosis (dose‑dependent, higher with 5 % vs 2 % formulations). 2

Test	Rationale (population)	Target/Interpretation
Serum ferritin	Iron deficiency is common in pre‑menopausal women with diffuse hair loss; supplementation benefit is uncertain.	Aim for > 70 ng/mL [2]
Complete blood count & serum iron	Detect anemia and assess iron stores.	Normal ranges appropriate for adult women [1]
Thyroid‑stimulating hormone & free T4	Subclinical hypothyroidism frequently presents with diffuse hair loss without overt symptoms.	TSH within laboratory reference; treat if abnormal [2]
25‑OH vitamin D	Low vitamin D levels are present in ~62 % of women with female pattern hair loss.	Replete to ≥ 30 ng/mL [2]
Serum zinc	Zinc deficiency occurs in ~15 % of affected women and correlates with lower mean levels.	Replete to normal adult range [2]
Total & free testosterone (LC/MS)	Excludes hyperandrogenism that can underlie androgenetic alopecia.	Values within female reference ranges [2]
Prolactin	Hyperprolactinemia can cause diffuse shedding and is often asymptomatic.	Normal adult female range [2]

Indication: consider low‑dose oral minoxidil (≈ 1.25 mg daily) when topical irritation, poor adherence, or patient preference precludes topical therapy. 1
Dosage range: 0.625–5 mg daily is used off‑label for telogen effluvium and female pattern hair loss, offering ease of use and no impact on hairstyle. 1
Absolute contraindications: pheochromocytoma, recent myocardial infarction, severe coronary artery disease, heart failure, and known hypersensitivity to minoxidil. 1
Precautions requiring specialist consultation: history of arrhythmia, hypotension < 90/60 mmHg, significant renal impairment, or dialysis dependence. 1
Adverse‑effect profile: facial hypertrichosis (~24 % incidence, dose‑dependent), transient shedding (16–22 %), mild peripheral edema (~2 %), and short‑lasting vasodilatory symptoms (dizziness, tachycardia, palpitations) that peak between days 3–7. 1

5 % minoxidil formulations (foam once daily or solution twice daily) are recommended as first‑line therapy for all adult women with hair loss, based on the 2019 Androgen Excess and PCOS Committee guideline, which cites superior efficacy over 2 % formulations. 2
Evidence level: high‑quality guideline (Level B) supporting the use of 5 % minoxidil in this population. 2

Visit 0 (initiation): start topical 5 % minoxidil, order comprehensive labs, counsel about expected shedding (weeks 2–8) and need for adherence. 1
Month 3: review laboratory results, begin targeted supplementation for any deficiencies, assess early response and manage side effects. 1
Month 4 (dermatology referral): formal clinical assessment with standardized photography; consider adding oral minoxidil if topical response is inadequate or poorly tolerated; scalp biopsy if diagnosis remains uncertain. 1