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SKINCARE DECODED • 54 MOISTURIZERS • 55

There are other forms of HA that are much smaller. Some studies suggest

that smaller HAs can penetrate the skin to plump, hydrate, and even bring

anti-aging benefits. However, some people can be sensitized by these

small HAs. So, as we always say: Patch-test, patch-test, patch-test (Chemists’

Commandment #9).

Emollients and Face Oils

Over the years, face oils have gained a lot of popularity, and every brand

is brewing its own version. You’ll find that they all seem to be 100% pure,

100% organic, 100% potent, and 100% exaggerated. Regardless of the claims,

face oils are a great addition to your routine to boost nourishment, add glow

“X% OF PEOPLE AGREE, SKIN FEELS MOISTURIZED” “STAY MOISTURIZED

FOR 24 HOURS!” “SKIN IS 75% MORE HYDRATED!”

Do these common moisturizer claims sound like random numbers yanked out of some

marketing exec’s behind? It turns out these claims are actually backed up by scientific studies.

Most moisturizer studies look at two values: hydration and TEWL.

Hydration is measured by a corneometer; this handheld device tracks skin’s dielectric (insulative

or nonconductive) properties, and reports hydration as a percentage. In a study, you’d typically

measure this value on clean skin, moisturized skin, and skin several hours after product application

to assess how hydrating a product is.

Remember: TEWL (pronounced like tool) stands for Transepidermal water loss. As the name

suggests, it’s how much water evaporates out of your skin. The higher the TEWL rating, the worse

the skin barrier. This is a really useful way to test several different claims. For example, the tester

may purposely damage a patch of skin to create an area with a high TEWL, then apply a particular

cream to bring the value back down. Neat, eh?

DECODE That Claim