By JENNIFER A. KINGSON


Whether flaked, liquefied or otherwise suffused in moisturizers and sunscreens, eye creams and lip balms, gold has become a go-to ingredient in skin care products. Spas advertise 24-karat gold facials. Fancy brands like La Prairie and Guerlain sell golden wares at expensive stores.

Gold, cosmetics executives say, is anti-aging, anti-inflammatory, antiacne. People who sell creams with gold flecks talk about the ability of those flecks to warm the skin and make it conducive to other ingredients. People who sell gold in nano form - that is, in microscopic particles suspended in a liquid mixture known as a colloid - look down on this crowd, saying that gold can confer benefits only when it is broken down small enough to penetrate the skin.

“Colloidal gold is the best option when you’re using gold,” said Laura DeLuisa LaRocca, founder of La- Rocca Skincare. “I’ve been using it for two years, and it definitely has changed my skin. It has tightened it, it has toned it, my lines have faded probably 40 percent.”

But is it true that gold has therapeutic qualities? Dermatologists say that gold cannot help you, but it absolutely can hurt you, causing inflammatory reactions like contact dermatitis. In high doses, gold can be toxic, but these products probably don’t contain enough of it to make that happen, doctors say.

Dr. Judith Hellman, a dermatologist in New York City, did research into gold face creams. “At best, they do nothing, and at worst, they can give you irritation of the skin,” she said. “I would tell people to put that money into gold that they can wear around their neck or on their fingers.”

Dr. Jeannette Graf, a dermatologist in Great Neck, a suburb of New York, said she had done “intensive medical searches on this very ingredient” and found that “there are absolutely no scientific studies that show that gold has any effect in firming or revitalizing the skin, nor that it reduces wrinkles or gives skin a plumped, golden glow.”

But Dr. Graf did find that gold was named “allergen of the year” in 2001 by the American Contact Dermatitis Society.

The skin care companies counter by saying that they have proprietary research showing the benefits of gold. Holly Genovese, a vice president at La Prairie, said that the company’s scientists had found a way to use gold that is valuable to the skin.

“Colloidal gold does help to maintain your skin’s elasticity and firmness,” she said.

When La Prairie’s Cellular Radiance Concentrate Pure Gold ($580 an ounce) was introduced , it was “the first big, major introduction of any major cosmetic company using gold in a skin care product,” Ms. Genovese said. The product has been “a huge hit for us,” she said.

Gold is certainly a trendy color this year, on everything from handbags to eye shadow. And the record-high price of gold may have something to do with it .

But not all products that contain gold are wildly expensive. A Christine Valmy mask costs $13.50 for one application.

Cosmetics makers habitually cite the use of gold in medicine, where it is given to patients with rheumatoid arthritis and has been used experimentally as a possible cancer treatment.

Mostafa El-Sayed, a professor at the Georgia Institute of Technology, said it was ridiculous to think that gold could fight wrinkles .

“The way it takes care of cancer, the nanoparticle goes only to cancer cells, none of the healthy cells,” he said. But try telling that to all those satisfied La Prairie customers. Ms. Genovese pointed out that people keep buying her company’s gold line because they perceive that it works.

“These products do more than just make a promise, they deliver on that promise,” she said.