Hair loss is surprisingly common in women, affecting more than 30 million in the U.S., according to the American Academy of Dermatology. It can start as early as puberty or much later in life. In fact, 38 percent of women 70 and older experience hair loss, in part because hair thickness decreases with age, especially after menopause. The condition often leads to low self-esteem, social anxiety, and self-imposed isolation.
Female pattern hair loss (FPHL) is characterized by thinning over the top of the scalp and sometimes the sides. In men, a male hormone known as an androgen is primarily responsible for hair loss, but the main cause of FPHL appears to be less clear-cut. Women normally produce male hormones too, and in some cases the condition is associated with excessive androgen levels. Other types of hair shedding in women may be related to estrogen loss or significant changes in estrogen levels, as in the postpartum period or in menopause. Hair loss can also result from breakage during hair treatments and styling, certain medication—including hormones—and conditions like iron deficiency, severe dieting, thyroid disease, lupus, and even stress.
Finasteride (Propecia) is approved by the Food and Drug Administration to treat male pattern hair loss (also called androgenetic alopecia). At higher doses, it's also approved to reduce the symptoms of enlarged prostate in men. It works by blocking the enzyme that is responsible for the conversion of testosterone to dihydrotestosterone, the androgen that causes the prostate to enlarge. It also reduces dihydrotestosterone levels in the scalp, which slows hair loss and even increases hair growth. Because finasteride has been effective in controlling male pattern hair loss, it has been used to treat female pattern hair loss, although it has not gained FDA approval for that purpose. Medication prescribed to treat a condition that does not have FDA approval for that use is known as "off-label." Doctors can legally prescribe any medication they deem appropriate for treatment.
"If a woman has female pattern hair loss and elevated androgen levels that we can document, then she is likely to respond to treatments that block or decrease androgens, and finasteride is an option," says Elise A. Olsen, M.D., a professor of dermatology and oncology and director of the Hair Disorders Research and Treatment Center at Duke University Medical Center. "But often we will try it even in women who don't have elevated androgen levels because other treatment options are very limited, and these women may have sensitivity to androgens at the cellular level of the hair follicle that we can't document."
What is the evidence?
The only randomized, double-blind, placebo-controlled trial on this subject involved 137 postmenopausal women with low androgen levels and hair thinning at the front of their scalp. After 12 months, there were no significant differences in hair count between the patients receiving finasteride or a placebo, and both groups continued to lose hair. The authors concluded that finasteride was well-tolerated but did not reduce hair loss in these women.
Another group of researchers studied 48 premenopausal women with FPHL and elevated androgen levels: 36 subjects were randomized to treatment with one of three drugs with anti-androgen effects, including finasteride, and 12 subjects declined treatment but were observed. The study wasn't blinded, meaning that patients and researchers knew which medication was received. After a year, those taking finasteride continued to lose hair.
In contrast, two studies reported some success with finasteride, but neither was randomized, blinded or placebo-controlled. In one, 37 premenopausal women with FPHL but without androgen excess received finasteride along with an oral contraceptive. After 12 months, most of them showed improved hair density, although the contraceptive contained drospirenone, which has anti-androgen actions and may have contributed to that effect. And in a 2010 study, 86 pre- and postmenopausal Asian women with FPHL and normal androgen levels were treated with finasteride for 12 months, resulting in slight increases in hair density for 57 women, moderate increases in 10 women, and more substantial increases for four women. Anecdotal reports and small, uncontrolled trials have also noted beneficial results with hair loss in pre- and postmenopausal women with or without increased androgen levels.
What are the risks and precautions?
Birth defects. Our medical consultants advise against the use of finasteride during pregnancy or in women who may become pregnant. Finasteride can cause genital abnormalities in the male fetus. Women who are pregnant or possibly pregnant shouldn't even handle crushed or broken tablets of finasteride because it can be absorbed through the skin.
Side effects. Few adverse reactions have been noted in women receiving finasteride. Increased body hair, sweating and hot flashes, and headaches were reported during clinical studies of women receiving finasteride, but those effects were also noted in women not receiving the medication. (See here for a list of side effects reported in men.)
Liver concerns. Finasteride should be used with caution by people with liver abnormalities because the drug is extensively metabolized in the organ.
Hair loss: What other options can you try?
Treat the underlying problem. The average person loses 50 to 100 hairs a day. Consult your doctor or a dermatologist if your hair is shedding in larger amounts, thinning, or falling out. Proper diagnosis and treatment may help slow hair loss. You should be referred to both a dermatologist and an endocrinologist to be screened for thyroid disease, iron deficiency, skin disorders, lupus, and other possible causes. If your hair loss is accompanied by excess facial and body hair, abnormal periods, or adult acne, your androgen levels should be tested.
Review all medication and supplements you are taking with your doctor. You may need to discontinue or change a drug if it contributes to hair loss. That may include certain antidepressants, antithyroid medicines, blood thinners, drugs for high blood pressure or heart problems, hormones, cholesterol-lowering medications, nonsteroidal anti-inflammatories such as ibuprofen (Advil, Motrin and generics) and naproxen (Aleve and generics), and retinoids (e.g., acitretin, isotretinoin).
Eat adequately. Certain diets—especially those that skimp on protein—can trigger hair loss.
Use the first-line treatment. Minoxidil (Rogaine and generic) 2 percent, an over-the-counter solution that's applied to the scalp, is currently the only FDA-approved medication for female pattern hair loss. Experts recommend trying the 2 or 5 percent version for 12 months before judging its effectiveness, although benefits may appear sooner. "Women use it for a month or two and assume it doesn't work," says Maria Hordinsky, M.D., a professor and chairwoman of the department of dermatology at the University of Minnesota. "But if you treat long enough, you can get results in most people." Your doctor may add an oral drug with anti-androgen effects, such as finasteride or spironolactone, if your hair loss appears to be androgen-related.
Change your hair-care practices. Avoid styles and treatments that can damage hair, including braiding, cornrows, tight ponytails, rollers, bleaching, coloring, chemical straightening or waving, blow-drying, and hot combs.
Cover your losses. Tinted powders, lotions, and sprays can camouflage hair thinning, as can extensions, hairpieces and wigs. But choose items that gently attach to the scalp via loose braids, pins, or simple placement. "Glues can be damaging," says Amy McMichael, M.D., a professor of dermatology at Wake Forest University School of Medicine in North Carolina. Volumizing shampoos swell the hair shaft, making it appear wider, but may cause breakage of fragile or damaged hair, she warns. Hair-restoration surgery permanently transplants hair from thicker to thinning areas of the scalp. "If you combine that with medication, you get a nice effect of slowing hair loss and increasing density," McMichael says.
Bottom line. Finasteride has been used to treat female pattern hair loss and is reported to be effective for some women, but to date there is no good evidence from well-designed clinical trials to support its use for that purpose. Our advice: If you're a woman with thinning hair or significant hair loss, talk with your doctor about a referral to a specialist to look for underlying causes and approved treatments, such as minoxidil (Rogaine and generic). Finasteride probably plays little or no role in reversing hair loss in women with normal or low androgen levels.
This off-label drug use report is made possible through a collaboration between Consumer Reports Best Buy Drugs and the American Society of Health-System Pharmacists. This is the 24th in a series based on professional reports prepared by ASHP.
These materials were made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by a multistate settlement of consumer fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).
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