If there's any doubt about whether lip balm stirs strong passions, see Lip Balm Anonymous, a Web site at www.kevdo.com/lipbalm, which suggests that lip balms are habit-forming ("Chap Stick Conspiracy: Just like the corner drug dealer," "Bonne Bell Lip Smackers: Getting your kids addicted is their primary goal"). While these claims are meant to be laughable, many people do take lip service seriously. And at this time of year, they have plenty of good reasons.

The cold, wind and lack of humidity wreak havoc with lips, because they lack the tough layer of skin that shields the rest of the face. Hundreds of products can protect lips, but they all have different properties, says Dr. Andrew Scheman, a Chicago dermatologist and co-author of "Cosmetics Buying Guide" (Consumer Reports Books, $14.95).

"The best lip moisturizer is still Vaseline or something like it, but it's very messy and tends to spread," Scheman says. "Sticks that are wax-based don't migrate as much, but also aren't as emollient."

Complicating matters are all the special ingredients. Some actually are irritants, says Paula Begoun, a consumer advocate who monitors the makeup industry and author of "Don't Go to the Cosmetics Counter Without Me," 4th Edition (Beginning Press, $19.95). Camphor, eucalyptus, menthol, peppermint and spearmint-included to soothe and cool-can leave lips worse off, she says.

Some ingredients included for their disinfecting properties, such as phenol, can make lips drier.

Read labels, and consider these matters before buying.

Medicated products: Medicated products are regulated as drugs by the Food and Drug Administration, says David Steinberg, a professor of cosmetic chemistry at Fairleigh Dickinson University in Madison, N.J. These products must contain some of the following ingredients in specific concentrations to be called medicated: allantoin, cocoa butter, petrolatum, shark liver oil, dimethicone and glycerin.

Medicated products may be extremely effective for keeping lips in good shape, but non-medicated products also can work well.

Pots vs. balms: Products in a pot, which are applied with fingers, are not necessarily less sanitary, Steinberg says, because they contain very little water, and bacteria need water to flourish. Never share balms, however, because they can transmit viruses, he says.

Cold sores: Medicated lip balms may help treat cold sores, Begoun says, but there is no research proving that they are totally successful. New research done on skiers, however, shows that a sunscreen that offers full-spectrum protection is very effective at reducing cold sore outbreaks, she notes. She cautions that products offer a full-spectrum sunscreen only if they contain zinc oxide, titanium dioxide or avobenzone, as does Clinique Lip Block SPF 15 ($7.50).

Exfoliating: "The lips are normally very flexible, but when you have hard, dead surface skin, it can cause them to crack and produce deep fissures," says Rebecca Pflueger, co-founder of English Ideas, a cosmetics company that emphasizes treatment products.

Scheman says alpha hydroxy acids and salicylic acid are used in many lip products to exfoliate, and suggests using one under Vaseline or Aquaphor ointment. Pflueger's company makes Lip Refine ($32), or Clinique's All About Lips ($20) is another option at department stores.

Still confused about what to use? A good place to start may be with the best sellers. Here's a list from some top beauty stores around the country.

New York City: At Clyde's on Madison Avenue, known for its European cosmetic lines, best sellers are Dr. Hauschka's Lip Care Stick from Germany ($7.50); Bloom's Aromatherapy Lip Gloss from Australia ($15); Molton Brown's Wet Lips from England ($15); and Alexandra de Markoff's Extra Help Gel for Lips ($20), an exfoliating product. (Call 800-792-5933.)

Dallas: At Beauty First, the best-selling balms are Redken's Skin Response Lip Conditioner ($7) and ARTec's Protecting Lip Balm ($5.98). Call 214-902-2290.)

Los Angeles: Naimie's Beauty Center, which stocks more than 10,000 brands, reports Carmex ($1.19) and Karite Lip's Shea Butter Lip Balm ($5) are popular. (Call 818-655-9933.)

Chicago: At Bravco, 43 E. Oak St., (312-943-4305), Neutrogena's Lip Moisturizer ($2.89) is most popular, while at Sherwyn's Health Food Shops, Reviva Labs Vitamin E Oil Stick for Lips and Eyes ($3.79) is selling briskly.