Scott-Vincent Borba, an entrepreneur in Woodland Hills, California, makes elixirs called Borba Skin Balance Water that hold all the allure of the fountain of youth. Shelved in refrigerators at Sephora stores under signs marked 「Drinkable Skincare,」 the plastic bottles contain mixtures of vitamins and plant extracts that promise to enhance the skin.

The label on the 「replenishing」 water for example, says it has been 「scientifically proven to improve moisture levels by an average of 66 percent,」 while the 「firming」 water advertises itself as 「scientifically proven to improve elasticity by an average 24 percent.」

Last year, Americans bought about one million bottles of Borba water, which cost $2.50 each, Mr. Borba said. They also bought the brand』s 「skin treatment infused」 gummi bears($25) and powders ($28) that promise to help improve cellulite and stretch-mark-prone areas in seven days.

「If you put good things into your body, your skin should reap the benefits,」 Mr. Borba said. 「You already drink water and you already eat candy and chocolate, so I am putting skin care into your water and your candy and your chocolate.」

For decades, cosmetic companies have manufactured face creams that offer hope in a jar. But now a growing number of beauty brands are introducing hope in a pill, a water bottle or even a candy bar.

But critics said there is little scientific proof behind the premise that these items will improve the look of the skin.
「We would all love to get smoother, younger, more elastic skin in seven days just by chugging drinks, eating candy bars or chewing gummi bear vitamins,」 said Wahida Karmally, the director of nutrition at the Irving Center for Clinical Research at Columbia University Medical Center. 「But skin doesn』t work that way. There is no magic bullet.」

Since food helps maintain skin health, one might assume that supplements improve skin. But Dr. James M. Spencer, a dermatologist in St. Petersburg, Florida, said that there is little evidence that dietary supplements enhance beauty.

「If you are already a healthy 55-year-old woman in New York, or if you just had a pizza for lunch, I doubt you will look prettier if you take beauty vitamins,」 said Dr. Spencer, a clinical professor of dermatology at Mount Sinai School of Medicine in Manhattan.

Carrie Mellage, an industry manger for consumer products at Kline & Company, a market research firm that tracks cosmetic sales, said that worldwide sales of nutri-cosmetics reached $1 billion last year, largely because of sales in Europe and Asia. Ms. Mellage said that increased interest in holistic medicine and organic food is driving sales.

「Consumers understand that you and your skin are what you eat,」 Mr. Borba said. 「Elixirs, droplets and effervescent tablets that fortify your skin from the inside out will become the skin care of choice in the next five years.」