How do I start oral minoxidil for a patient with androgenetic (genetic) alopecia or female‑pattern hair loss, including initial dose, baseline labs, contraindications, monitoring, and alternative options?

Starting Oral Minoxidil for Androgenetic Alopecia and Female Pattern Hair Loss

For women with androgenetic alopecia, start oral minoxidil at 0.5–1 mg daily after mandatory cardiovascular screening, and for men start at 2.5 mg daily, with the understanding that topical minoxidil 5% combined with PRP remains more effective than oral monotherapy. 1, 2, 3

Pre-Treatment Cardiovascular Screening (Mandatory)

Before prescribing oral minoxidil, you must screen for cardiovascular contraindications—this cannot be bypassed 2:

• Take a detailed cardiovascular history focusing on heart failure, pericardial disease, coronary artery disease, and uncontrolled hypertension 2
• Measure baseline blood pressure and heart rate in both sitting and standing positions to assess for orthostatic changes 2
• Absolute contraindications include pre-existing pericardial disease, uncontrolled hypertension, and pregnancy 1, 2, 3
• Avoid oral minoxidil entirely in patients with existing cardiovascular conditions due to rare but serious risks including pericardial effusion 1, 2

Initial Dosing Protocol

For Women

• Start at 0.5–1 mg once daily (women require lower doses due to higher adverse effect rates, particularly hypertrichosis) 1, 2, 3
• The international Delphi consensus supports 1.25 mg/day as the standard starting dose, with a range of 0.625–5 mg/day 3
• Women have significantly higher overall incidence of adverse effects compared to men 1, 2

For Men

• Start at 2.5 mg once daily with a therapeutic range of 1.25–5 mg/day 3
• Men tolerate higher doses better than women 1, 2

Dose Titration

• Do not exceed 5 mg daily in routine practice—doses above 5 mg are associated with significantly increased dizziness, lightheadedness, hypertrichosis (17.5%), and tachycardia (3.5%) 1, 4, 5
• If inadequate response at 3–6 months, consider increasing by 0.5–1 mg increments rather than exceeding 5 mg 3, 4

Baseline Laboratory Testing

No routine laboratory tests are required before starting oral minoxidil for androgenetic alopecia 2:

• Unlike spironolactone (which requires potassium monitoring in at-risk patients) or isotretinoin (which requires liver and lipid monitoring), oral minoxidil does not need baseline labs 2
• This makes oral minoxidil more convenient than alternative systemic treatments, though cardiovascular screening remains mandatory 2

Monitoring During Treatment

Clinical Monitoring at Follow-Up Visits

• Assess for hypertrichosis (unwanted facial/body hair growth)—occurs in 17.5% at higher doses and is more common in women 1, 2, 4, 5
• Check for lower extremity edema—more common in women 1, 2
• Monitor for orthostatic symptoms (dizziness, lightheadedness)—minoxidil's hypotensive effect lasts approximately 72 hours despite a 4-hour half-life 1, 2
• Measure heart rate for tachycardia (occurs in 3.5% of patients) 1, 2, 4, 5
• No ongoing laboratory monitoring is required during treatment 2

Efficacy Assessment Timeline

• Evaluate treatment response at 3,6, and 12 months using multiple objective measures 1, 2:

  • Standardized before-and-after photographs 6, 1
  • Trichoscopy to measure hair density and diameter 6, 1
  • Hair pull test to evaluate hair fragility 6, 1
  • Patient self-assessment questionnaires 6, 1, 7

• Expect 61–100% of patients to show objective improvement in androgenetic alopecia, though response is variable 1, 8

• Warn patients about transient shedding (occurs in 16–22% during the first 2–3 months) 3

Critical Comparison: Oral vs. Topical Minoxidil

Oral minoxidil 1 mg is as effective as topical minoxidil 5% in treating androgenetic alopecia, but topical minoxidil 5% combined with PRP shows superior efficacy to either treatment alone 1, 7:

• A 2024 randomized controlled trial found no significant difference in hair diameter or patient satisfaction between oral 1 mg and topical 5% minoxidil 7
• However, combination therapy (topical minoxidil 5% twice daily + monthly PRP injections for 3 sessions, then maintenance every 6 months) achieves 57% median increase in terminal hair density versus 48% with minoxidil alone 6, 1
• The practical advantage of oral minoxidil is improved patient compliance compared to twice-daily topical application 8, 3

When to Consider Combination Therapy Instead

If the patient can tolerate topical application, strongly consider starting with topical minoxidil 5% plus PRP rather than oral monotherapy 6, 1:

• Apply topical minoxidil 5% (1 mL) twice daily 6
• Add PRP injections monthly for at least 3 sessions (5–7 mL PRP at 0.05–0.1 mL/cm², 90-degree angle, 2–4 mm depth, 1 cm apart) 6
• Use pharmaceutical-grade topical anesthetic cream before PRP due to significant pain 6
• Maintenance phase: 1 PRP session every 6 months 6
• This combination achieves 83% negative hair pull test rate (indicating reduced hair fragility) 6

Alternative Treatment Options

Low-Level Laser Therapy (LLLT)

• Use FDA-cleared 655 nm laser devices three times per week as adjunctive therapy 6
• Requires continuous indefinite use to maintain regrowth (similar to minoxidil) 6
• Abrupt cessation results in loss of gains within months 6

Platelet-Rich Fibrin (PRF)

• Emerging alternative to PRP with theoretical advantages including lower cost, simpler preparation, and sustained growth factor release 6, 1
• Preliminary studies show comparable safety and efficacy to PRP 6
• No randomized controlled trials available yet (as of 2023) 9

Common Pitfalls to Avoid

• Failing to screen for cardiovascular disease before initiation—this is mandatory and cannot be skipped 1, 2
• Starting women at the same dose as men—women require lower doses (0.5–1 mg vs. 2.5 mg) due to higher adverse effect rates 1, 2, 3
• Exceeding 5 mg daily—higher doses significantly increase adverse effects without proportional benefit 1, 4, 5
• Inadequate treatment duration—some patients require extended therapy beyond 6 months for optimal response 6
• Low platelet concentration, inadequate injection volume, or insufficient treatment frequency leads to PRP treatment failure if combination therapy is chosen 6
• Individual genetic factors significantly influence response to all treatments—set realistic expectations 6

Patient Counseling Points

• Treatment must be continued indefinitely—discontinuation leads to reversal of hair growth benefits within months 6
• Hypertrichosis is common (17.5% at higher doses)—unwanted facial/body hair growth may occur, particularly in women 1, 2, 4, 5
• Transient shedding in the first 2–3 months is normal and does not indicate treatment failure 3
• Maximum response typically achieved by 6 months, with 25% improvement in hair density at 2 months predicting sustained response at 6 months 6
• Oral minoxidil is contraindicated in pregnancy or women planning to become pregnant due to lack of safety data 1