Bangkok: Minoxidil, a drug approved by the U.S. Food and Drug Administration (FDA) for the treatment of hereditary hair loss, is not a permanent solution to the problem. Hair loss resumes once the medication is discontinued. Minoxidil's mechanism involves stimulating blood flow to the hair follicles, thereby prolonging the hair growth phase. Users are required to apply the topical solution to the scalp twice daily to see visible results, which can take anywhere from two months to a year.
According to Thai News Agency, minoxidil was originally developed as a treatment for high blood pressure but was later found to have hair growth properties during clinical trials in the 1970s. This led to the development of a topical 2% minoxidil solution for male hair loss in 1988 and for female hair loss in 1991, eventually becoming available over the counter in the United States in 1996. A more effective 5% solution was later introduced, which has since become the standard treatment for hereditary hair loss.
Minoxidil works by dilating blood vessels in the scalp, increasing blood flow to hair follicles, and prolonging the anagen (growth) phase. Randomized controlled trials have demonstrated that applying minoxidil twice daily can increase hair growth by 8-12 hairs per square centimeter, with maximum effectiveness observed after one year of continuous use. The treatment is particularly effective in younger male patients who have been experiencing hair loss for less than five years.
However, minoxidil has limitations. It is FDA-approved only for treating hair loss at the crown of the head and is most effective at the hairline when used in the early stages of hair loss. The medication can also aid in hair regrowth for cancer patients who have lost hair due to chemotherapy, though it is ineffective if hair follicles have been destroyed, such as in burn victims. Clinical trials indicate that minoxidil is more effective in female patients than male patients, with only 40% of male users experiencing moderate hair regrowth.
The requirement for twice-daily application and the delayed results contribute to a low adherence rate among users, many of whom discontinue use before completing the recommended one-year period. Common side effects include itchy scalp and scalp rash, while less common effects can include acne, burning sensations, increased hair loss, and facial swelling.
Minoxidil's effectiveness relies on continuous use, failing to address the root genetic causes of hair loss such as excessive testosterone levels that lead to smaller hair follicles and accelerated hair loss. Therefore, while minoxidil can temporarily manage hereditary hair loss, it is not a cure.
For effective use, guidelines from the Mayo Clinic recommend applying minoxidil to a dry scalp, starting at the center of the target area, and avoiding hair washing for four hours post-application. Hair dryers should not be used immediately after application, and users should wash their hands thoroughly, especially if they have pets, as minoxidil can be toxic to animals.