I've always had healthy, wash-and-wear hair—long, blonde, straight, and low-maintenance. It's the kind of hair you take for granted until you move to L.A., city of Paris Hilton—style extensions. When women here began asking if my hair was real, I suddenly felt lucky and upped my game with products. I moussed, smoothed, and glossed on a daily basis. But within four years, the balance of power shifted. Damage had crept up on me like the California tide, and without those products, my hair looked frayed and dull.

When a top stylist advised me to lop off the same amount of length that Gwyneth had, I winced as if he'd already made the cut. Visions of all the preppy girls from high school—with their polo shirts and bobbed hair—sent me into denial. I decided that cutting would be cheating, like choosing lipo over the gym. Instead, I tried frantically to repair my hair. I let it air-dry, stretched the months between highlights, and slept in deep conditioner—but nothing stopped my split ends from splintering higher. So I sought out stylist Corey Powell at The Salon by Maxime in Beverly Hills. The man behind the hair masks that keep the manes of Cameron Diaz, Drew Barrymore, and Renée Zellwegger healthy between shade-shifting movie roles, Powell is best known for his all-natural "hair therapy" programs.

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As he inspects my head, Powell tells me that damaged hair gets nicks in the surface of the cuticle. "These are like tiny dings in the hair's protective armor that weaken the strand until it breaks," he explains. Coloring, harsh shampoos, sun exposure, and heat styling can all cause this kind of damage, but since mine is concentrated in the lower five inches rather than at the crown, he suspects my product habit is largely to blame—especially my weakness for items laced with dimethicone, the most common form of silicone.

That smoothing ingredient acts as a barrier, sealing out moisture; it's as adept at de-frizzing hair as waterproofing shoes (yes, it's used for both). But there's the rub. "If you inhibit the moisture content of the hair shaft too often, you end up with dry hair," says trichol-ogist Philip Kingsley. However, silicone is so commonplace it's hard to avoid. Kingsley recommends finding products that list it low on the label and using them sparingly. But Powell suggests I go completely styling-product-free for my month of rehab. Am I at Promises for hair? I feel both betrayed by my products and anxious at the thought of giving them up. Clearly, I need to make changes, so I commit.

To get my hair naturally silky again, Powell also prescribes twice-weekly scalp-treatment masks at his salon that consist of pomegranate and camellia oil, avocado, egg white, banana, honey, milk, and follicle-rejuvenating rosemary. Once he applies the mask, Powell spends a heavenly five minutes brushing my scalp to increase blood flow and stimulate growth. "Anything you do to improve the health of the scalp will improve your hair," he says. Then he uses the heat of a hair dryer to push the oils into my frayed, flyaway ends and protect them from shampooing. (Shampoo removes dirt and oil, but the fragile ends of the hair don't get oily, so repeated washing dries them out.)

After three appointments, I have fewer flyaways and less frizz. My hair feels heavier but not weighed down. (Powell attributes this improved density to the deposited proteins.) On the fourth visit, he's able to blow it dry without detangling it first, and it doesn't knot. By the sixth, my highlights are brighter. "You see more color variation in healthy hair," Powell explains. So I follow his other guidelines, too: I switch to a sulfate-free shampoo, which is less likely to fade color; I start wearing a hat in the sun; and I stop showering in really hot water. Studies show that hair is more vulnerable to sun damage in very dry (or very humid) climates and loses more of its natural keratin in high-temperature water.

By month's end, Powell pronounces the majority of my notches gone, and I'm amazed at the difference. My hair is legitimately soft without any styling aids, and naturally shiny. It took a while to get the hang of the pre-shampoo oil-and-blowdry ritual, but the results have me sold. I'm not sure I'll keep it up at home, and I am going back to volumizing mousse, but it's a greener, Powell-approved version from Aveda. Leaving the salon, I run into two friends, one of whom has extensions. They ooh and aah over my long, healthy hair, and this time, I feel like I've earned it.

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