Skin Deep

Read the fine print: Watch out for ‘in-vitro’ testing


Special to The Miami Herald

These days, it’s impossible to open a magazine without seeing advertisements for skincare products that boast some pretty incredible claims. But instead of being swayed by hype, it’s important to read the fine print — literally.

If you look closely, in many cases you’ll see an asterisk, and something along the lines of “based on in-vitro testing.” So what does this mean for you, and what does this mean in terms of a product’s effectiveness?

“In vitro” is Latin for “in glass,” so when you see this referring to some sort of clinical testing, it means the results are based on lab testing — as opposed to testing on actual human skin. “In-vitro” skincare ingredient testing involves skin cells in a petri dish, which means that the ingredients’ ability to penetrate to the deeper levels of the skin cannot be assessed. This isn’t always a bad thing, but in most instances, these “in-vitro” results don’t translate to human skin — or treating the beauty concern or skin condition that the product is claiming.

Think of it this way: No matter how great an ingredient works on skin cells in a glass dish, it’s useless if it cannot penetrate the upper stratum corneum layer of the skin and get to the deeper cells.

One example of an ingredient with great “in-vitro” results that does not translate to skin benefits is the family of peptides. In the lab, peptides have been shown to boost collagen production, reverse skin damage, lighten discoloration and do much more.

But while many skincare companies tout these “in-vitro” results, they fail to disclose that most peptide molecules are too large to penetrate the skin — which means they can’t possibly deliver their in-lab results in real life.

My advice: When you see “in vitro” in an advertisement for some groundbreaking, revolutionary product with never-before-seen results, buyer beware. If they were able to achieve those results in women like you, don’t you think they’d include that in the ad?

“In vivo” testing is another method for assessing the efficacy of skincare ingredients. This means something is tested on live animals or humans, and these results are always more convincing. Of course, animal testing is frowned upon, so look for “in vivo” testing on live human subjects.

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