Efficacy and Safety of 2.5 mg versus 5 mg Oral Minoxidil for Androgenetic Alopecia: A Comparative Study

To compare the efficacy and safety of oral minoxidil 2.5 mg versus 5 mg once daily in male patients with androgenetic alopecia.

Two-arm, parallel-group, randomized, double-blind comparative clinical trial conducted at a single center in 58 male patients with androgenetic alopecia. Participants are randomly allocated to receive oral minoxidil 2.5 mg or 5 mg once daily for 6 months, with 29 participants in each group.

Participants will receive the assigned oral minoxidil dose once daily for 6 months. They will be followed monthly by clinical examination, blood pressure and heart rate measurement, assessment of lower-extremity edema, and recording of adverse events. Standardized scalp photography and dermoscopy will be performed at baseline and at month 6, and hair density and hair shaft diameter will be assessed using 3D Slicer. The patient and the treating physician are blinded to the dose allocation.

Male patients aged 19–45 years with clinically diagnosed androgenetic alopecia, classified as Hamilton–Norwood grade 1–4, who provide informed consent to participate. Patients with cardiovascular disease, hypotension, renal disease, severe drug hypersensitivity (including TEN, Stevens–Johnson syndrome, or DRESS), or cardiac arrhythmia/non-sinus rhythm on electrocardiography will be excluded.

Participants will be randomly assigned to two parallel treatment groups. Group 1 will receive oral minoxidil 2.5 mg once daily, and Group 2 will receive oral minoxidil 5 mg once daily for 6 months.

Change in hair density and hair shaft diameter and clinical assessment of androgenetic alopecia from baseline to 6 month. Incidence and severity of adverse events during the 6-month treatment period

Participants will be randomly allocated to two separate groups according to a randomization schedule.

The patient and the outcome assessor are blinded to the dose allocation.

Individual participant data will not be shared publicly due to privacy and confidentiality considerations. Only aggregated and anonymized study results will be reported in the final publication.