Skincare Decoded. Victoria Fu

      SKINCARE DECODED • 14 BASICS 101 • 15

      Your skin is like an

      onion—it́s got layers.

      Epidermis This is the outermost layer of skin and

      consists of cells called keratinocytes, which have a kind

      of weird, oval shape. Keratinocytes constantly regen-

      erate and move “up” toward the outer layers.

      Dermis The second main layer of skin. This

      is the structural layer holding everything “up.”

      Skin Biology 101

      W

      hy, yes! A skincare book does always start with a diagram of the layers

      of your skin. Here’s another one, except we’re only highlighting the

      components that you’ll encounter in important skincare-science concepts

      and common marketing lingo. Feel free to refer to this when you can’t figure out

      what exactly that newly launched product is referring to.

      SKINCARE DECODED • 14 BASICS 101 • 15

      Sebaceous Gland Responsible for secreting sebum,

      which helps protect the skin from external aggressors,

      keep it pliable, and prevent it from getting dehydrated.

      Outside Aggressors UV rays

      and pollutants are just a few of

      the aggressors your skin has to

      deal with!

      Stratum Corneum (fondly referred to—by us,

      anyway—as the SC): The phrase is Latin for

      “horny layer” (teehee), and the SC mostly consists

      of dead keratinocytes called corneocytes. This is

      the outermost layer of the epidermis.

      Hair Follicle Just what it

      sounds like! Where those

      hairs sprout from.

      SKINCARE DECODED • 16 BASICS 101 • 17

      Lipid Matrix In a nutshell, this barrier keeps

      the bad guys (pollutants, pathogens) out and

      the good guys (water!) in. This is why you hear

      all that talk about “barrier functions”—it helps

      prevent water from evaporating out of the skin,

      causing dry skin. More technically, the integrity

      of this matrix is important to overall skin health,

      as itʼs the reason the skin surface is mainly hy-

      drophobic. Consists mostly of ceramides, fatty

      acids, and cholesterol.

      Hyaluronic Acid This popular skincare ingre-

      dient is actually naturally found in your skin in

      both the epidermis and dermis as a structural

      support and water grabber.

      Acid Mantle & Microbiome Your SC has a

      slightly acidic pH that acts as a great defense

      system. Fun fact! The pH of your skin affects the

      little microbes living on its surface. There are

      theories out there that tie elevated skin pH to

      irritation and even acne.

      A Closer Look: Epidermis

      N

      ow that we’ve established some basics, let’s zoom in on the epidermis,

      as that’s where most skincare products go to work.

      You Are Here

      Melanocytes Responsible for the pigment

      in your skin. They produce melanosomes

      (small packets of pigment) as a protective,

      defensive reaction to sun damage. Some-

      times they can get carried away due to

      excessive sun damage and stress, and cause

      freckles and hyperpigmentation (dark spots).

      Your anti-dark-spots serum targets these

      little guys.

      Natural Moisturizing Factors (NMFs)

      Though your SC is mostly fatty, it requires some

      level of water to function correctly. Meet your

      NMFs. Molecules like urea, lactic acid, and so-

      dium PCA act as your skin’s naturally occurring

      water grabbers.

      Corneocyte

      Lipid Matrix

      Natural

      Moisturizing

      Factors

      (NMF)

      Cermide

      Free

      Fatty

      Acid

      SKINCARE DECODED • 16 BASICS 101 • 17

      SC Our friend the

      ”horny layer” (it’s okay

      to giggle again!), the

      outer layer of the

      epidermis.

      Keratinocytes

      Your skin cells.

      Corneocyte The end form of, and

      a type of, a keratinocyte.

      Acid Mantle

      SKINCARE DECODED • 18 BASICS 101 • 19

      Fat Who could forget fat? It does so

      much for us, after all! But seriously,

      your skin depends on that fatty layer,

      so donʼt hate too much.

      A Closer Look: Dermis

      T

      hough most skincare excitement happens in the

      epidermis, the dermis still plays an important

      role. In fact, it is