It's certainly not the rocket variety, but there is a science to keeping skin hydrated and supple. Here's a quick tutorial.

By Jenny Jin
Updated January 20, 2015
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What Causes Dry Skin?
Cold air holds less moisture, so a dip in the temperature is one factor. Soap is another: The same suds that cleanse skin can also strip it dry, mostly due to chemical surfactants, which remove dirt but also skin oils. And many people lather all over, which isn't necessary more than once a week, says Neal Schultz, a dermatologist in New York City and the founder of He recommends sticking to hands, feet, underarms, the groin, and under the breasts. Other sebum sappers? Long, hot showers (keep them warm and under 10 minutes) and aging (your skin produces less oil as you get older).

Ingredients To Look For
"There are two musts: humectants, which attract water to skin, and emollients, which trap the water in," says Schultz.


  • Lecithin
  • Propylene glycol
  • Sorbitol
  • Hyaluronic acid


  • Petrolatum
  • Lanolin
  • Dimethicone

When Is Dry Skin Something More?
Flaking and feeling "tight" are normal symptoms of dryness. But if they're accompanied by redness, swelling, excessive itchiness, or crusting, you should consult your dermatologist. "It could be an allergy or something more, like eczema," says Schultz. Either way, your doctor can help treat it.

How Can You Prevent It?
Counterintuitive as it may seem, you should start with a gentle scrub. "Without proper exfoliation, your moisturizer can't penetrate and doesn't do its job," says Schultz. Once a week, in the shower, use one containing lactic acid, such as DermaDoctor KP Duty Body Scrub ($46, It dissolves dead cells and acts as a humectant. Skip formulas with sharp grains, like walnut shells, which can be too abrasive. Another tip? Get a humidifier. "I like to compare it to drying a wet towel in muggy weather. No matter how long it sits there, it won't completely dry because of the moisture in the air," says Chan. And in the case of your skin, that's a good thing.

When Should You Moisturize?
You've probably heard that you should slather yourself while skin is still wet, as this traps the moisture. Instead, pat yourself mostly dry, then apply, so you don't dilute the formula, says Ling Chan, an aesthetician in New York City.