Androgenetic alopecia, also known as male- or female-pattern baldness, is caused by dihydrotestosterone (DHT). This compound shrinks hair follicles, which kills the hair. Ordinarily, women have a minute amount of testosterone, but high-androgen birth control pills, ovarian cysts, pregnancy, or menopause may increase it. Over-the-counter minoxidil and prescription ketoconazole, finasteride, aldactone, spironolactone, cyproterone, hormone replacement therapy, and oral contraceptives are androgenetic alopecia treatments.
Minoxidil, also known as Rogaine or Regaine, is an over-the-counter medication that comes in a 2% strength for women and a 5% strength for men. Twice a day minoxidil is massaged into the scalp. Researchers believe that this medication works by opening blood vessels and potassium channels, which allows more oxygen for the hair follicles. It may take up to 12 weeks before any results are noticeable. Some people may experience scalp irritation when using this treatment.
Some studies show that minoxidil 2% actually works better for women than other androgenetic alopecia treatments. Nineteen percent of women between 18-45 years old experienced hair regrowth after using minoxidil for eight months. Reportedly, 40% of study participants had minimal regrowth.
Ketoconazole, sold in the U.S. as Nizoral, is a shampoo typically prescribed for sebhorreic dermatitis. Doctors found that this shampoo may be a valuable addition to the arsenal of androgenetic alopecia treatments. They report that when this shampoo was used 2-4 times a week, men regrew their hair almost as well as they did on minoxidil.
Finasteride, also known as Propecia, is an oral medication that binds the enzyme responsible for converting testosterone into DHT. This drug is known to cause severe birth defects and is not prescribed to women. It passes easily through the skin, and pregnant women or women who might become pregnant must not handle crushed or broken pills.
Propecia is often recommended as a first choice to combat men's hair loss. Sometimes it is used in combination with minoxidil. In long-term research on 1,553 men 18-41 years old, 83% maintained or increased their hair count after taking 1 mg of finasteride daily during a two-year study.
Side effects of finasteride may include a decreased libido, erectile or ejaculatory dysfunction, testicular pain, or the development of gynecomastia. A Swedish study warns that the sexual side effects may be irreversible. UK research warns of a possible increased risk of male breast cancer.
Other androgenetic alopecia treatments are aldactone, spironolactone, and cimetidine. Aldactone and spironolactone slow the production of androgen and block DHT. Cimetidine, also known as Tagamet, is a histamine blocker usually used to treat ulcers. It has been found to block DHT and has been used successfully to treat hirsuitism in women. These androgenetic alopecia treatments are not recommended for men.
Another DHT blocker is cyproterone acetate. Its initial use was to reduce excessive aggression and sex drive in men, but has also been used for women with severe hirsuitism and androgenetic alopecia. It is available in Europe, but not in the U.S.
Hormone replacement therapy and oral contraceptives may be prescribed to women as androgenetic alopecia treatments. These medications reduce the amount of androgen produced by the ovaries. Only low-androgen birth control pills should be used to combat hair loss; high-androgen pills can exacerbate the problem. Mood changes, spotting, skin discoloration, weight gain, nausea, and/or irregular bleeding are possible side effects of hormone therapy and oral contraceptives. They should not be taken by women with liver disease, heart disease, blood clots, cancer, or those who are pregnant.