Prescription Topical Minoxidil Availability
Topical minoxidil is available over-the-counter (OTC) in both 2% and 5% formulations and does not require a prescription in the United States or Canada. However, higher concentrations (such as 15%) can be compounded by prescription for patients who fail to respond to standard OTC formulations 1.
Standard OTC Formulations
- Minoxidil 2% and 5% solutions and foams are FDA-approved and available without prescription for female pattern hair loss 2, 3.
- The 5% foam formulation was approved by Health Canada and the FDA for female pattern hair loss in 2014, providing once-daily application convenience 3.
- Both concentrations are well-tolerated without evidence of systemic adverse effects in controlled trials 2.
Prescription Options for Non-Responders
- For women who fail to respond to 5% topical minoxidil (approximately 60% of patients), a compounded 15% topical minoxidil solution can be prescribed 1.
- In a 12-week study, 60% of non-responders to 5% minoxidil achieved clinically significant response (>13.7% increase in hair count) with 15% topical minoxidil 1.
- This higher concentration did not cause significant hemodynamic changes or adverse events in the study population 1.
Comparative Efficacy of Standard Formulations
- 5% topical minoxidil demonstrates superior efficacy to 2% minoxidil in patient-assessed treatment benefit at 48 weeks, though both are superior to placebo 2.
- The 5% formulation shows increased occurrence of pruritus, local irritation, and hypertrichosis compared to 2% minoxidil 2.
- Once-daily 5% foam showed similar efficacy to twice-daily 2% solution, though formal noninferiority criteria were not met in one trial 4.
Alternative: Oral Minoxidil
- Low-dose oral minoxidil (1 mg daily) can be prescribed for patients who fail or cannot tolerate topical therapy 5.
- Oral minoxidil 1 mg is as effective as topical 5% minoxidil in treating female pattern hair loss, with response rates of 18-82.4% 5.
- Mandatory cardiovascular screening is required before initiating oral minoxidil, as it is contraindicated in patients with pre-existing cardiovascular disease 5.
- Common side effects include hypertrichosis (17.5%), edema of lower limbs, and orthostatic hypotension 5.
Combination Therapy Considerations
- Combining topical minoxidil 5% with platelet-rich plasma (PRP) shows greater efficacy than either treatment alone 5, 6.
- The recommended protocol is topical minoxidil 5% twice daily plus PRP injections monthly for at least 3 sessions, then maintenance every 6 months 5.
- This combination results in 1.74 times increase in hair density and 14.3 times increase in hair diameter 7.
Clinical Caveat
Before initiating any minoxidil therapy, evaluate for underlying causes of hair loss including thyroid dysfunction and iron deficiency, as management differs significantly for other forms of diffuse alopecia 6, 7.