Women are often surprised to find they are losing their hair. At drugstores, they will spend untold amounts of money on products that claim to build back volume or reverse the damage of hair loss. One expert, Paradi Mirmirani, a dermatologist and assistant clinical professor at the University of California at San Francisco, explains how hair changes as we age and why we should chow down on protein.

Never Say ‘Bald’

In women, just as in men, the most common type of hair loss, or alopecia, is hereditary thinning. It is popularly believed to be inherited from one’s mother’s side, but actually could come from both parents, says Dr. Mirmirani, who specializes in hair disorders. It is as likely to affect women as men. “Fifty percent of everyone will develop some degree of hereditary hair loss by 50, but it can start as early as age 20 or even the teens,” she says.

In women, the pattern of hereditary thinning is different than in men; it is referred to as female pattern thinning. “Women don’t go bald or have a receding hair line,” she explains. “Instead you might notice some thinning on top of the head as opposed to at the back, or that your scalp is more visible or your pony tail isn’t as thick.”

Everyone experiences a normal five-to-seven-year cycle of growth and shedding of hair. At any given time, 10% of the hair is in the resting phase and not growing; the follicle, or hair root, will push out the old strand with a new, short strand.

Around 100 to 200 strands of hair loss a day is normal. “That is the amount that you should be able to replace daily, and that shedding is fine,” says Dr. Mirmirani.

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