Facials can feel nice. But, says DC dermatologist Beverly Johnson, a facial offers no medical benefit—unless it includes exfoliation, the removal of dead surface skin.

Fortunately, most spa facials include some sort of exfoliation. The esthetician might apply a mild scrub to the skin. Another method is microdermabrasion, in which crystals are sprayed on the skin, then suctioned up along with dead cells. Exfoliation can also be done by applying chemicals to the skin.

Dr. Eliot Battle of Cultura Medical Spa in Chevy Chase DC says that taking off dead cells helps to unclog pores. Clogged pores can get bigger and irritated, leading to the formation of bacteria that cause pimples. Peeling away layers of epidermis also helps to lessen the appearance of wrinkles, even out pigment, remove acne scarring, and minimize sun damage. The deeper and more invasive the peel, the more effective the results.

Is a chemical peel painful? Viewers of Sex and the City might think so after seeing the episode where Samantha comes out of hers the color of a boiled lobster.

The acids used in chemical peels can be broken into three categories: superficial or light, midlevel or medium, and deep. Most spas offer light peels, while doctors—some of whom now own medical spas—offer light to deep peels.

Light peels usually involve alpha-hydroxy acids or beta-hydroxy acids. Popular AHAs are glycolic acid (sugar in liquid acid form) and lactic acid (milk in liquid acid form). A familiar BHA is salicylic acid, which can treat acne.

Of all the peels administered, light peels are the most common. At local salons, we found prices ranging from $55 to $165. The acids can sting or burn while on the skin, but the discomfort stops when the acid is washed off.

Medium peels usually use trichloracetic acid. TCA peels, which remove deeper layers of skin, require seven to ten days’ downtime. Side effects include redness, blistering, oozing, and crusting.

“You look like you’ve been dipped in acid,” DC dermatologist Marilyn Berzin says of TCA peels, which should be performed by a doctor in a medical setting. Her practice charges $700.

This is especially the case for anyone with skin of color, says Dr. Johnson. If the acid in a peel is too strong, it can cause changes—sometimes permanent—in pigmentation.

In a deep peel, phenol acid is used to peel off the deepest layers of epidermis and reach into the upper dermis. These serious peels, rarely performed these days, involve EKG monitors and IVs, says Dr. Berzin. Downtime is at least ten days, and side effects include significant redness, blistering, oozing, and crusting.

Many doctors say that deep peels are being supplanted by laser treatments. Lasers, though more expensive, involve less pain and downtime. A deep phenol peel might start at $1,000, says Dr. Berzin, a proponent of lasers. Treatment with a Fraxel laser that requires several sessions might cost $1,000 to $1,200 a session. (For more on laser treatments, see our guide to nonsurgical anti-aging procedures at washingtonian.com/noknives.)

This article is part of the 2008 Great Day Spas Package. To read more articles like it, click here.