BASICS 0
T
here’s no denying it—the skincare industry is a hot, hot
mess! Toners, serums, essences . . . ampoules, creams,
gel creams . . . lotions, masks—what does it all really
mean?! And how do I even begin shopping for what I really
need?! We feel you, so let’s dissect these questions piece
by piece. But before diving into products, let’s cover all the
fundamentals. With a good understanding of how your skin
works, different skin types, and an intro to the skincare-
products landscape, you’ll at least feel more comfortable
with these overwhelming options. Welcome to Skincare 101!
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