Did you ever stop to think why so many dermatologists have such flawless skin? Could it be genetics, or have they been obsessed with complexion care from childhood? To find out, we went right to the sources and got eight top skin doctors to divulge everything -- from the skin-saving habits they've adopted to the products they can't live without.

1. Never use the same product year-round.

"Because skin is a living organ that's constantly affected by everything from hormones to humidity, I use a variety of products -- some only in certain seasons and others just on certain days," notes 40-something Susan Taylor, M.D., director of the Skin of Color Center at St. Luke's-Roosevelt Hospital in New York City. In winter, when her skin is drier, she uses a moisturizing cleanser like Cetaphil Gentle Skin Cleanser ($6; at drugstores). In summer, she switches to normal-to-oily formulations like L'Oréal Plénitude Hydra Fresh Foaming Gel ($5; at drugstores).

2. Always wash your face before hitting the sheets.

"Get the goop off your skin before you go to bed," says 43-year-old San Francisco-based dermatologist Kathy Fields, who is meticulous about her nightly face-washing routine. (What doesn't get wiped off migrates into the pores, where it sets the stage for blemishes, she explains.) Fields suggests using cleansers formulated with pore-purging benzoyl peroxide or salicylic acid like Clinique Acne Solutions Cleansing Foam ($17.50; and Neutrogena Oil-Free Acne Wash ($5.79; at drugstores), both with salicylic acid.

3. Get enough shut-eye.

Sleep deprivation can result in puffy eyes, sallow skin and breakouts, says 48-year-old Chappaqua, N.Y., dermatologist Lydia M. Evans, M.D. (You need from eight to nine hours nightly.) If you do end up with morning puffiness, New York dermatologist Amy B. Lewis, M.D., swears by Neova Eye Therapy ($40;, which contains the anti-inflammatory ingredients found in Preparation-H.

4. Soak away stress.

While any form of relaxation will do wonders for your skin, Lewis loves bubble baths. "I take them to unwind four or five nights a week," says the 38-year-old director of dermatologic and laser surgery at Downstate Medical Center in Brooklyn. State University of New York. (Lewis likes anything fruit scented, like Origins Fretnot tangerine bubbling bath, $22.50;

5. Give skin the rub.

"Exfoliation makes skin more radiant," says 46-year-old Katie Rodan, M.D., associate clinical professor of dermatology at Stanford University in Stanford, Calif. An advocate of chemical and mechanical exfoliation (think topically applied creams and lotions as compared with scrubbing granules or a Buf-Puf), Rodan uses a scrub like M.D. Formulations Scrub ($35; on her face every morning and a vitamin-A-based wrinkle-smoothing, skin-sloughing prescription medication like Renova ($60 per tube) at night. Her reason for the two-pronged approach (which should be worked up to over several months to prevent irritation): "Physically sloughing off dead skin cells loosened by vitamin-A creams will help your moisturizer better penetrate the skin and your makeup go on much more smoothly."

6. Hydrate your skin from the inside out.

"It's not possible to have good skin if you don't drink enough water," says Mary Lupo, M.D., associate clinical professor of dermatology at Tulane University School of Medicine in New Orleans, who downs a minimum of six glasses a day. "When you're dehydrated, your skin is one of the first organs to show it."

7. Waste not, age not.

"After applying sunscreen to my face, I rub whatever is left on my hands onto my neck and chest, two areas people always forget," says Lewis, who uses sunscreen with an SPF of at least 15 every day. (You can also do the same thing with anti-aging creams.) Dermatologist-recommended sunscreens include Avon Skin-So-Soft Moisturizing Suncare Plus SPF 30 ($12; and SkinCeuticals Ultimate UV Defense Sport SPF 45 ($34;

8. Give skin below the neck its due.

"We often neglect the skin on our bodies," says Evans, who makes sure to give herself an in-shower sloughing with a body scrub (which can get rid of dead skin cells and make skin smooth) every other day. "You would have to use a washcloth very harshly to get the same results you get from the fine granules of a good scrub," she adds. (Try Clarins Exfoliating Body Scrub, $28;, or Aveda Smoothing Body Polish, $18; .)

9. Feed the skin with exercise.

"Exercise boosts circulation and keeps oxygen and nutrients flowing to the skin, giving it a fresh, radiant look," says 35-year-old bicoastal dermatologist Karyn Grossman, M.D., who never misses her 6:30 a.m. run -- either outdoors in Santa Monica or in the gym when she's in New York City. She's also an avid hiker and loves to sail and scuba dive. Lewis takes a more low-key tack to fitness: three one-hour sessions of Iyengar yoga every week at her local gym.

10. Don't let skin go up in smoke.

"I don't just not smoke, I avoid smokers and smoky situations at all costs," Lupo says. "When I make a reservation at a restaurant and they ask, 'Smoking or non?' my reply is, 'Not even close.'" Smoking constricts the capillaries, depriving the skin of much-needed oxygen, Lupo explains.

11. Always apply moisturizer after washing hands.

Dry, indoor air, cold weather and frequent washing can suck the moisture out of the skin on your hands. Grossman knows from personal experience; she estimates that she washes her hands at least 30 times a day. Grossman's favorite: Aquaphor Healing Ointment ($8; at drugstores). Others to try: Vaseline Intensive Care Renew & Protect Lotion ($2; at drugstores) or Dr. Hunter's Rosewater & Glycerine Hand Creme ($10;

12. Feed your face with vitamin C.

"I put vitamin-C products in the hedge-your-bets category," says Rodan, who uses one under her sunscreen to combat the free radicals produced by whatever ultraviolet light that gets through. A study published in the Swedish dermatology journal Acta Dermato-Venereologica showed that when used with a sunscreen, vitamin C provided added protection against ultraviolet B (sunburn-causing) and ultraviolet A (wrinkle-causing) rays. Rodan's picks: serums that contain L-ascorbic acid, the form of vitamin C shown in studies to be more readily absorbed by the skin's cells. Products that contain L-ascorbic acid include Cellex-C High-Potency Serum ($90; 800-CELLEX-C), SkinCeuticals Topical Vitamin C High Potency Serum ($60; and Citrix Cream L-Ascorbic Acid 10% ($50;

13. Experiment with caution.

"I spend several thousand dollars a year trying new products, but I don't try them all at once," says Lisa Airan, M.D., clinical instructor of dermatology at Mt. Sinai Hospital in New York City, who's in her early 30s. Airan routinely sees patients with dermal disasters -- like breakouts and red, raw skin -- caused by overuse of products. Those particularly susceptible: women with acne or sensitive skin, who should only use products formulated for their skin type unless otherwise directed by their dermatologist.

Skin-Care RX

Doctor-created skin-care lines are sold in dermatologists' offices, department stores and specialty stores like Sephora. But are they any better than other skin-care products? "Generally, these products contain stronger concentrations of ingredients like alpha hydroxy acids," says Susan Taylor, M.D., director of the Skin of Color Center at St. Luke's-Roosevelt Hospital in New York City. Here are a few dermatologist lines for you to try, based on what's right for your skin type.

If you have acne, try Proactiv. Pimple-fighting benzoyl peroxide is the main ingredient in this line developed specially for skin prone to breakouts (800-235-6050).

If you're starting to see faint lines and wrinkles, try:

* M.D. Skincare has everything from cleansers to vitamin-C-based sunscreens. Our favorite is the Alpha-Beta Peel Home Facial System, a do-it-yourself peel kit ($65;

* Murad skin-care products are infused with antioxidants like vitamin C and pomegranate extract. One of its best products: Eye Complex SPF 8 ($50; 800-33-MURAD).

* DDF (Doctor's Dermatologic Formula) contains a wide variety of products, but the gel-based sunscreen that absorbs instantly is a must-have ($22;

If your skin is oily (or just looks oily), opt for the Dr. Mary Lupo Skin Care System. One of our favorites is the nongreasy Daily Age Management Oil-Free Moisturizer SPF 15 ($23;

If you want scientific-based skincare with a botanical bent, look no further than Dr. Brandt Skincare. This line contains something for everyone (even men). We like the Lineless Soothing Mask ($35; at department stores or