When it comes to skin care products, we all love pretty packaging. But, we also know that it’s what’s inside—in other words, the right ingredients—that’s most important. In my years as a dermatologist, however, I’ve realized that even the savviest product aficionados fail to take into account something that’s every bit as important as ingredients: the means in which these ingredients are delivered into the skin. The skin’s function is to keep the outside world out, and it is a very effective barrier. Many of my patients spend thousands of dollars every year on the latest and greatest formulations, but very few take the time to ensure they’re applying them properly to maximize absorption. The result? These coveted ingredients literally evaporate into thin air, or even wash off, before getting a chance to absorb—and my patients are left without the results they expected, disenchanted with the products, and reaching for their credit cards to spend even more money on something else.