Treatment of Hair Loss with Minoxidil
Lilian White, MD
Posted on December 16, 2024
Hair loss affects approximately 80 million people in the United States. Moderate to severe hair loss significantly affects quality of life and is associated with reduced work productivity, anxiety, and depression. Hair loss is categorized as scarring or nonscarring. Nonscarring hair loss is the most common form of alopecia. In cases of scarring hair loss, referral to a dermatologist for further evaluation and biopsy is generally recommended. Hair loss may be diffuse, focal, or patterned.
Telogen or anagen effluvium are the most common causes of diffuse, nonscarring hair loss. Patients typically describe hair loss as coming out in large clumps. Usually, telogen effluvium follows an acute emotional or physiological stressor. The COVID pandemic particularly highlighted this phenomenon, with 25% of patients in one study demonstrating telogen effluvium following infection with COVID-19.
Other causes of telogen effluvium include vitamin D or other nutritional deficiency, thyroid disease, and certain medications. Telogen effluvium may also be idiopathic. Anagen effluvium occurs after chemotherapy treatment. Treatment of telogen effluvium includes addressing any underlying causes and reassurance the condition will typically improve in 6 to 9 months. In some cases, telogen effluvium may be chronic. Although telogen effluvium and androgenic alopecia are considered benign conditions, patients may desire treatment for cosmetic reasons.
Minoxidil is a first-line treatment for androgenic alopecia (a form of patterned alopecia). In men, androgenic alopecia typically presents with hair thinning at the temples or vertex of the scalp. In women, androgenic alopecia may present with thinning of the vertex of the scalp with a retained frontal hairline (although the hairline may also recede).
Minoxidil may also be used in patients with concomitant androgenic alopecia and telogen effluvium. Topical minoxidil prolongs the anagen phase of the hair cycle to prevent hair loss, among other mechanisms. A dose of 5% topical solution twice daily seems to be the most effective. A 14% to 18% increase in scalp hair is the expected outcome at 1 year of treatment in women. Similarly, the peak effect of minoxidil appears to occur at about 1 year of treatment. Topical minoxidil is safe and generally well tolerated. Some patients may experience contact dermatitis.
Oral minoxidil at low doses has also been studied as a treatment for androgenic alopecia and chronic telogen effluvium in both sexes. A dose of 0.25 to 5 mg daily has been studied with beneficial results. Oral minoxidil stimulates hair growth and may result in excess facial hair growth in women. Other adverse effects of oral minoxidil include hypotension, tachycardia, headache, insomnia, and increased hair shedding with initiation of treatment. However, it is estimated only 1% of patients discontinue treatment because of adverse effects. Increased hair shedding typically occurs between weeks 2 to 4 of treatment and resolves at approximately 6 weeks. To reduce hair shedding with initiation, overlap with topical minoxidil is sometimes recommended; however, this strategy has not been well studied.
Minoxidil (topical or oral) is not typically recommended or effective for forms of focal alopecia, such as alopecia areata or traction alopecia. It is important to let patients know that with discontinuation of minoxidil, gains in hair loss will recede to a level that would be expected without treatment. Additional information on the evaluation and management of hair loss may be found in a recent AFP article.