Most cosmetic companies don't bother putting their products through independent clinical trials required for designation as a drug because it's costly and time consuming. It also isn't practical for them continually to resubmit new evidence every time they tweak their formulas. When they do, it can pay off big-time.
In 2007, a popular British drugstore chain offered published scientific proof that its inexpensive wrinkle cream actually worked. Consumers practically caused a stampede through the streets of London trying to get their hands on it. More recently, Procter $ Gamble's Olay Professional Pro-X enjoyed a big sales bounce after announcing an independent clinical trial that showed it improved the appearance of fine lines and wrinkles.
Day said that the majority of major brand products are rigorously tested, even if the results aren't submitted for independent review. In her opinion, many of the beauty product claims she's seen tend to be more overstated than understated.
Kenet isn't so sure. He said many over-the-counter products are good but he wouldn't classify them as great. "In general, I think cosmetic companies over-claim and under-deliver. I'd like them to see them make fewer claims and deliver more," he said.