Minoxidil: How it works and what to expect
Minoxidil is an over-the-counter topical treatment for hair loss. Here's what the evidence shows about effectiveness, side effects, and how long results take.
What minoxidil does
Minoxidil is a topical medication applied directly to your scalp to slow hair loss and regrow hair. It's available over the counter in 2% and 5% strengths, with the 5% version showing better results in clinical trials.
How it works
The exact mechanism isn't fully understood, but minoxidil appears to widen blood vessels in the scalp and extend the growth phase of hair follicles. This can shift hairs from the shedding phase back into active growth.
What the evidence shows
About 2 in 3 people using minoxidil see some hair regrowth or slowing of loss. Results vary widely. Some see visible improvement in 3 to 4 months; others need 6 months or longer. If you stop using it, hair loss typically resumes within weeks.
Side effects
Common side effects are mild and localized to the scalp: irritation, dryness, or itching. Unwanted facial hair growth is possible but uncommon with proper application. Rare systemic effects like dizziness or increased heart rate can occur if minoxidil absorbs systemically, particularly with higher concentrations or broken skin.
Practical considerations
Minoxidil requires consistent, daily application indefinitely to maintain results. Cost is relatively low compared to prescription alternatives. It works best for vertex (crown) hair loss and is less effective for receding hairlines.