NEW YORK CITY (By Nastasha Singer, NYTimes) April 24, 2006 — Willy Manriquez has perfected a sales pitch that stops most women dead in their tracks.

"Do you want me to take away the laugh lines from around your eyes in less than a minute?" Mr. Manriquez, a salesman for the skin care brand Freeze 24/7, asks shoppers as they roam the cosmetics floor of Henri Bendel in Midtown. The makers of Freeze 24/7 products claim to reduce the appearance of wrinkles by relaxing facial muscles.

Most passers-by welcome Mr. Manriquez's anti-wrinkle demo, he said. But he occasionally meets a skeptic like Janice DiGiovanni, 47, who owns the Absolute Laser spa in Rhinebeck, N.Y.

The motto of her clinic, which offers laser procedures and acid peels, is "We do what skin care products promise to and don't," Ms. DiGiovanni said last week, as she settled onto a stool in front of Mr. Manriquez and prepared for disappointment. "I'm thinking moisturizer is a moisturizer is a moisturizer."

Mr. Manriquez dabbed an eye serum and an antiwrinkle cream around her right eye. "Your muscles are getting used to relaxing, so your smile lines are not as deep," he said. "You look better already."

Ms. DiGiovanni, who said she regularly gets antiwrinkle Botox and Restylane injections, held up a mirror and examined her face with an experienced, critical gaze.

"I can actually feel the plumpness around my eye. It feels more firm," she said with some surprise. Then she demanded that Mr. Manriquez "freeze" her left eye. "I have to say I'm excited."

Excited she was indeed. She left the counter after spending $385 on four products.

But some dermatologists and plastic surgeons are skeptical of Freeze 24/7. "It's like putting glue on your face to lessen the movement," said Dr. Trevor M. Born, a plastic surgeon in Toronto. "The numbing agent in it may make you lose the perception of the surface of the skin, making you feel that your face is swollen and tighter."

Thanks to visceral responses from first-time clients like Ms. DiGiovanni, upstart Freeze 24/7 has become a force to be reckoned with in the cosmetics industry. When it was introduced at Henri Bendel in October 2003, the brand had only one product, which was displayed on a rickety coffee table. Today, it has six products and is sold in more than 1,000 stores in the United States, including Nordstrom, Bloomingdale's and, as of last month, 447 Victoria's Secret branches.

The company had sales of $25 million in 2005, up from $5 million in 2004, said Scott E. Gurfein, the president and chief executive of Freeze 24/7. Out of every 10 people who stop for a skin care demonstration, he said, eight or nine plunk down $115 for the antiwrinkle cream.

"Put product on, see product work, buy product," Mr. Gurfein said. "It's not rocket science."

In a world of demanding consumers accustomed to the immediacy of high-speed Internet connections and instant messaging, Freeze 24/7 has become the leader in a new cosmetics category: instant skin care. Traditional skin care items, including prescription creams like Retin-A, take one to three months to show any kind of result because of the time needed for ingredients to slough off dead skin cells and stimulate new collagen growth.

Fast-acting products that offer immediate brightening, lightening, lifting or tightening effects often work by using ingredients that temporarily camouflage blemishes, spackle the skin, or stiffen it, making it feel tauter.

But many of those instant products do not provide long-term benefits, doctors say. Quick-fix beauty items are to cosmetics what cellphone cameras are to technology: they are fun to use and offer instant gratification, but their results can be fuzzy.

"Skin care is like dieting," said Karen Grant, the senior beauty industry analyst for the NPD Group, a market research firm. "You have to invest time and effort. There is no instant miracle cure."

Try telling that to the shoppers who are attracted to Freeze 24/7's cool, ice-cube-like packaging and its cool — or coolant-like — name. The word "freeze" suggests that wrinkles may be frozen temporarily, Mr. Gurfein said. The antiwrinkle cream is supposed to work by relaxing facial muscles in a less invasive fashion than Botox, the injectable toxin used to paralyze facial muscles temporarily, he said.

The company says the freezing effect comes from two ingredients: gamma aminobutyric acid, a substance found in the human nervous system that can block signals between nerves and muscles, and gynostemma pentaphyllum extract, derived from an herb used in traditional Chinese medicine. The company contends that gamma aminobutyric acid, a molecule that stays on the skin's surface, activates smaller gynostemma molecules and sends them through the skin, where they signal muscles to relax, according to Gene Beilis, a pharmacist who is the vice president for product development at Freeze 24/7.

But the company has no scientific evidence to back up its claim that its products actually affect facial muscles. Asked to provide microscopic data showing that the ingredients penetrate the skin, Mr. Beilis said that the company has "not gone into deeper levels of testing."

"You wouldn't be able to see the chemical interactions occurring under a microscope anyway," he said.

Nava Dayan, a senior principal scientist at Lipo Chemicals, which makes raw materials and ingredient technology for the cosmetics industry, said there is a standard test performed on cadaver skin, the Franz diffusion cell method, that can show whether a cosmetic formula permeates superficial and deeper levels of the skin.

Because the Food and Drug Administration defines cosmetics as products that do not fundamentally alter the skin, cosmetics companies are not required to prove if or how their products work on the skin's appearance.

In 2003, Freeze 24/7 had an outside company test the product by having a researcher treat the faces of 20 women and visually assess their wrinkles. The test concluded that each woman had an "observable decrease in the appearance of wrinkles" around the eyes ranging from 50 to 90 percent. Those results suggest that the product does something to the surface of the skin, but does not indicate that muscles are involved in the process.

Dr. Born, the plastic surgeon in Toronto, theorizes that Freeze 24/7 really works by numbing the skin on impact and then solidifying when it dries, making the face feel tighter.

Mr. Beilis agreed that gamma aminobutyric acid is a powdery substance that coagulates when it dries, gripping the skin in place. Another ingredient in the product, eugenol, a clove derivative used in dentistry as an analgesic, "gives you a cool, numbing, tingling sensation," he said.

But Freeze 24/7 devotees do not care about science as long as the product works instantly, said Mr. Gurfein, the company president. He said the brand has been successful because other skin care companies "focus on technology against a demographic that doesn't care how a product works; they just want it to work."

At Henri Bendel, Freeze 24/7 is the best-selling skin care line, far outstripping beauty brands created by doctors, including N. V. Perricone M.D. and Patricia Wexler M.D., said Claudia Lucas, the store's senior vice president and merchandise manager for beauty.

But even if the products work only superficially, they may have a long-term benefit, said Dr. Diane C. Madfes, a dermatologist in Manhattan.

"You are instantly limiting the movement of the skin by putting a restrictive barrier on your face," Dr. Madfes said. If such a product is used daily, it may train the face to stop making movements that cause furrows, she said. "So you may prevent new wrinkles from forming or already-existing wrinkles from getting worse."

Dr. Born offered an alternative treatment for frown lines: Scotch tape. Ever since they were teenagers, five of his patients have been taping their foreheads every night, and they have no frown lines now that they are in their 30's and 40's, he said.

There are no published clinical studies that prove Scotch tape reduces wrinkles, but it costs only $2.19.