Beauty Glossary
A clear, beauty-native guide to skin, makeup, nail, texture, finish, and routine language.
Written for real decisions at the mirror: precise enough to be useful, restrained enough to stay in beauty care territory.
Concepts
Skin Barrier Function
What the skin barrier is, why it matters, and how to tell when it's compromised.
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Concepts
Transepidermal Water Loss (TEWL)
The science of how skin loses water and why it drives dehydration.
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Concepts
Skin pH
Why the acid mantle matters and how products affect your skin's pH.
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Processes
Retinization
The adjustment period when starting retinoids — what to expect and how to manage it.
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Concepts
Comedogenic Ratings
What comedogenicity means and how to read ingredient ratings.
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Concepts
Humectants
The water-magnet family — glycerin, panthenol, hyaluronic acid — and how they pull moisture into the upper skin layers.
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Concepts
Emollients
The softeners — lipids and oils that smooth rough, flaking skin by filling the gaps between corneocytes.
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Concepts
Occlusives
The sealers — ingredients that form a physical film over skin to stop water from evaporating.
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Processes
Skin Cycling
A four-night rotation — active, active, recovery, recovery — that spaces strong actives so skin can repair between doses.
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Techniques
Double Cleansing
Oil first, then water — the two-step cleanse that removes sunscreen and sebum without stripping.
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Terms
How to Read an INCI List
The ingredient deck on every cosmetic — what the order means, what percentages are disclosed, and what marketing names hide.
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Techniques
Patch Testing
A simple compatibility check before a new formula reaches the face.
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Ingredients
Niacinamide (Vitamin B3)
The quiet overachiever of modern skincare.
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Ingredients
Retinal (Retinaldehyde)
One conversion step from prescription-strength results.
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Ingredients
L-Ascorbic Acid (Vitamin C)
The antioxidant gold standard — when it is fresh.
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Ingredients
Hyaluronic Acid
A moisture magnet that holds up to 1,000× its weight in water.
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Ingredients
Ceramide Complex (3:1:1)
The mortar between your skin-cell bricks.
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Ingredients
Salicylic Acid (BHA)
The oil-soluble exfoliant that cleans inside the pore.
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Ingredients
Glycolic Acid (AHA)
The smallest AHA — deepest surface reach.
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Ingredients
Lactic Acid (AHA)
Exfoliation that hydrates while it works.
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Ingredients
Azelaic Acid
The redness-and-marks multi-tool.
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Ingredients
Tranexamic Acid
The modern answer to stubborn dark spots.
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Ingredients
Squalane
Skin-identical softness, zero grease.
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Ingredients
Panthenol (Pro-Vitamin B5)
The calming humectant.
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Ingredients
Centella Asiatica (Cica)
K-beauty's calm-the-skin ambassador.
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Ingredients
Madecassoside
Cica's isolated active fraction.
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Ingredients
Bakuchiol
The plant-based retinal alternative.
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Ingredients
Peptide Complex
Signal molecules that tell skin to rebuild.
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Ingredients
Copper Peptide (GHK-Cu)
The regeneration peptide.
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Ingredients
Ferulic Acid
The antioxidant stabilizer.
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Ingredients
Vitamin E
The lipid-phase antioxidant.
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Ingredients
Resveratrol
The grape-skin longevity antioxidant.
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Ingredients
Caffeine
The de-puff vasoconstrictor.
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Ingredients
Allantoin
The keratolytic softener.
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Ingredients
Urea
The moisture-binding exfoliator for rough skin.
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Ingredients
Zinc PCA
The sebum referee.
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Ingredients
Sodium PCA
The forgotten natural moisturizing factor.
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Ingredients
Glycerin
The most proven humectant in existence.
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Ingredients
Jojoba Oil
The wax that behaves like skin sebum.
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Ingredients
Argan Oil
The Moroccan lipid classic.
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Ingredients
Kojic Acid
The ferment-derived brightener.
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Ingredients
Alpha-Arbutin
The gentle bearberry brightener.
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Ingredients
Phytosphingosine
The barrier lipid with antibacterial poise.
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Ingredients
Cholesterol
One-third of the barrier's golden ratio.
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Ingredients
Propolis
The hive's antibacterial resin.
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Ingredients
Green Tea Extract
EGCG's calming cup for skin.
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Ingredients
Retinol
The classic that started the vitamin-A era.
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