Minoxidil 5%

Overview

Minoxidil 5% is a topical solution or foam used for the treatment of androgenetic alopecia (pattern hair loss) in men and, in some cases, women. It belongs to a class of drugs known as vasodilators, specifically potassium channel openers, which were originally developed for high blood pressure. When applied to the scalp, it stimulates hair regrowth and slows further hair loss.

How Minoxidil 5% works

Minoxidil works by opening adenosine triphosphate–sensitive potassium channels in vascular smooth muscle cells, leading to hyperpolarization and vasodilation. This improves perifollicular blood flow, but its exact mechanism in promoting hair growth is not fully understood. It is thought to stimulate hair follicles to enter and prolong the anagen (growth) phase, increase follicular size, and promote cellular proliferation. Topical absorption also contributes to systemic vasodilation, though to a lesser extent.

Uses

• Treatment of androgenetic alopecia (male pattern baldness) in men and female pattern hair loss in women.
• May be used off-label for other types of hair loss under specialist guidance.

Side effects

• Common: local scalp irritation, dryness, scaling, itching, erythema, and unwanted facial or body hair growth (if applied too heavily).
• Serious (seek medical help): rapid heartbeat, dizziness, fainting, chest pain, sudden unexplained weight gain, swelling of hands or feet, severe scalp irritation, or allergic reactions like rash, hives, or difficulty breathing.

Precautions

• For external use only. Avoid contact with eyes, mouth, or broken skin; rinse with water if accidental contact occurs.
• Do not use if pregnant, trying to conceive, or breastfeeding without medical advice.
• Caution in patients with cardiovascular diseases (e.g., coronary artery disease, heart failure, arrhythmias). Systemic absorption may worsen angina or cause hypotension.
• May interact with other antihypertensives; use with caution if taking blood pressure medications.
• Not recommended for sudden or patchy hair loss, or hair loss due to childbirth, chemotherapy, or unknown causes.
• Wait at least 4 hours after application before washing or wetting the scalp. Do not apply to sunburned or irritated scalp.