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More than half (56 percent) of women who use anti-aging facial skincare say they're not sure these products work, but they use them anyhow, reports the marketing research company NPD Group. This is a sad state of affairs, don't you think? Here's one way to be sure to get what you pay for.

"I recommend a combination of antioxidants and sunscreen in the morning and a retinoid in the evening," says Arielle Kauvar, MD, clinical professor of dermatology at New York University Medical Center. Look for a product containing antioxidant vitamin C (L-ascorbic acid) in a light-protected bottle or tube; vitamin C protects against UV damage and regenerates natural stores of vitamin E, says Kauvar. (She suggests SkinCeuticals C E Ferulic, $142. Or try PCA Skin C-Quench, $64.) A moisturizer should contain emollients like shea butter or petrolatum—which seal in moisture—and humectants like glycerin or hyaluronic acid—which draw water into the skin—she says. (Dr. Dennis Gross Hydra-Pure Intense Moisture Cream, $125, and Sadick Dermatology Group AM Protection Cream, $36, are excellent moisturizers.) A retinoid (such as Retin-A, Refissa or Tazorac) stimulates new collagen and promotes exfoliation—key to a glowing complexion as you age.