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.