Glossary

Aigoo: the best place to find Korean skincare that works!

At Aigoo, we're always looking for ways to make skincare more accessible. With our Glossary, you'll be armed with all the knowledge to make the best decisions for your skin! We explain everything, from ingredients to chemical terms, products and even common phrases you might find on packages and in articles. Enjoy!

Skin Essentials

Normal: Some people are just naturally blessed! Normal skin isn't too oily or dry, with fine pores, little imperfections or sensitivity, and a radiant complexion. Jealous. 

Dry: Dry skin often has a taut, scaly, and dull appearance. There may be red patches and some itchiness. People with dry skin are also more prone to developing wrinkles. 

Combination: People with combination skin usually have oily T-Zones and dry areas elsewhere. 

Oily: People with oily skin have enlarged pores, and have greasy-looking skin. They're also more prone to developing pimples.  

Sensitive: Sensitive skin can be broken down into four subcategories: acne, rosacea, stinging/burning, and contact dermatitis. All of them are characterised by inflammation. 

T-Zone: The oiliest area of your face, which tends to be your forehead, nose, and chin.  

Skin barrier: This refers to your outermost layer of skin, made of dead skin cells glued together by oily substances called lipids. A healthy skin barrier will prevent bacteria from entering, limit water loss, and replace dead skin cells without clogging pores.

Help! Do I have...

Blackheads: An open, uninflamed pore filled with sebum, bacteria, and dead skin cells. The black colour is due to the oxidisation of the sebum and bacteria. 

Whiteheads: A closed, uninflamed pore clogged with sebum and dead skin cells. 

Pustule: An inflamed spot that looks like a red, sore bump, with white pus at the top. 

Papule: An inflamed spot that looks like a red, sore bump. 

Chemistry Demystified

Abrasives: An ingredient that polishes or cleans through rubbing or grinding. Common abrasives in K-beauty include brown sugar. 

Absorbents: You’ll most likely find absorbents in clay face masks, where they absorb sebum from the skin. 

Active ingredients: These are the ingredients that actually affect the human body - whether it’s brightening, fighting acne, hydrating, or more. Look out for these in your products!

Antioxidants: An ingredient that stabilises formulas and helps slow the ageing process by fighting free radicals that damage collagen.

Astringents: These ingredients help tighten pores - the main astringents in skincare are either alcohol-based or made from witch hazel. 

Chelators: Molecules that stabilise formulas and prevent deterioration by catching metal ions.  

Comedogenicity: This term describes the ability of a formula to clog your pores. The comedogenic scale ranges from 0 (no clogging) to 5 (severe clogging).

Emollient: This moisturising ingredient works by filling empty spaces on the skin surface and replacing lost oils in the outermost layer of the skin. Common emollients in K-beauty include shea butter and ceramides.

Fragrances: These compounds make your product smell lovely! However, they can be irritating for those with sensitive skin.

Humectant: This moisturising ingredient pulls water from the deeper layers of the skin to the outer layer. Common humectants in K-beauty include hyaluronic acid and glycerin.

Occlusive: This moisturising ingredient HATES water - it stops water from entering and exiting through the skin. Common occlusives in K-beauty include lanolin and beeswax.

pH buffers: These handy ingredients can stabilise and thicken formulas, but they’re also useful for matching our own skin pH level. Common pH buffers include citric acid and lactic acid. 

Preservatives: These are super important for preventing mold, yeast, and bacteria in your products. Common preservatives in K-beauty include Vitamin C.

Retinoids: Otherwise known as Vitamin A, these ingredients are essential in anti-aging and antiacne products.

Skin rejuvenators: This moisturising ingredient is specifically formulated to restore the skin barrier. Common skin rejuvenators include collagen and keratin.

Solvents: These help dissolve other ingredients in the formula, changing the texture of your products. Common solvents include glycerin. 

Surfactants: These ingredients are most frequently used to lower surface tension between two ingredients, which can help with cleansing or emulsifying. 

Thickeners: These ingredients do what they say on the tin - they help make products more thick and nice to apply! Common thickeners include xantham gum and cetyl alcohol.

Individual Ingredients

AHA: Alpha Hydroxy Acids are skin exfoliants that helps replace the entire skin, leaving your skin soother and more evenly pigmented. Incorporate it slowly into your routine, and be careful applying it in the daytime - use a sunscreen up to 24 hours after application to prevent damaging your skin. 

Artemisia: Otherwise known as mugwort, this plant is famed for its anti-inflammatory and anti-acne capabilities. 

Ascorbic acid: Otherwise known as Vitamin C, this boosts collagen production, fades dark spots, and can boost UV protection with sunscreen. 

BHA: Beta Hydroxy Acids are skin exfoliants that penetrate the pores to expel excess sebum and dead skin cells. Again, incorporate slowly and use a sunscreen up to 24 hours after application to prevent damaging your skin. 

Centella asiatica extract: Otherwise known as cica, this plant has strong antioxidant and anti-acne properties - it was traditionally used to heal wounds! 

Galactomyces: This is essentially fermented yeast, and can help reduce pore size, control sebum and slow ageing. 

Glutathione: This peptide can reduce fine lines, wrinkles, and brighten your skin by neutralising free radicals.

Glycolic acid: One of the most common AHAs you’ll find in skincare products, derived from sugar cane. 

Hyaluronic acid: Hyaluronic acid is another humectant that makes skin look glowy, fresh, and youthful, making it perfect for dry skin. 

Propolis extract: Bees use this to build their beehives, and humans can use this to soothe skin and reinforce their skin barrier. 

Salicylic acid: This is commonly found in plants like willow bark, and is a common BHA found in skincare. 

Snail secretion filtrate: Otherwise known as snail mucin, this slimy stuff is a fantastic humectant and promotes skin cell regeneration. 

Standard Products

Cleanser: Cleansers get rid of dirt and excess sebum. Korean cleansers are usually oil or foam cleansers, but they can come in many different formulas: 

  • Exfoliant: Exfoliants clean your skin too, but they remove dead skin cells, along with other debris. They might be do this physically (e.g. scrubs) or chemically (e.g. AHA/BHAs). 
  • Peeling gel: These are a type of exfoliant that usually come in a gel formula. Rub it on damp/dry skin, and watch your dead skin cells turn into little balls! Gross, but fun. 
  • Clay mask: These function differently to the famous sheet mask. You spread these on your skin, and the clay absorbs excess oil - hence why they're considered cleansing products. 

Toner: Korean toners try to rebalance your skin pH level back to its optimum level, but some may also help reduce pores or aid the acne-fighting process.

Essence: These are thin, liquidy products that usually add an extra layer of hydration to your skin. 

Serum: These products are super concentrated with active ingredients to address specific skin concerns. 

Ampoule: Ampoules are even more concentrated than traditional serums - they’re like booster shots, intended for short-term use. 

Sheet mask: These are staples in Korean skincare! They also address specific skin concerns by coating your face with essence or serum - the sheet mask prevents the liquid from evaporating so you get the full benefits.

Eye cream: Eye creams are specifically targeted for the delicate, thin skin around your eye - they can hydrate, reduce fine lines, or help with dark circles. 

Moisturiser: Every skin type needs a good moisturiser! They hydrate the skin and are essential for maintaining a healthy skin barrier.

Sleeping pack: These thick moisturisers are designed for nighttime use to aid skin cell regeneration and deep hydration. Apply before bed and rinse off in the morning. 

Sunscreen: Any product that provides protection to the skin against harmful UV radiation. There are two types: chemical sunscreens absorb UV rays before they reach your skin, whereas mineral sunscreen physically block the rays instead.

Popular Phrases

10-step routine: The famous Korean 10-step routine is said to include an oil cleanser, a foam cleanser, an exfoliant, a toner, an essence, a serum/ampoule, a sheet mask, an eye cream, a moisturiser, and then SPF for the day and a sleeping pack for the night! Whew!

Double-cleansing: Korean skincare usually starts with this process of using an oil then foam cleanser to properly rid your skin of impurities. 

Glass skin: This is the goal for every K-skincare fanatic! Glass skin is so poreless and smooth, it's almost see through. 

Pilling: You know when you rub product into your face, and instead of absorbing, it turns into tiny little balls? Yup, that’s pilling. 

Slugging: A trend where you lock your moisturisers in with a thick occlusive such as Vaseline - it’s meant to give you super plump, moist skin!

White cast: Some sunscreens can leave a noticeable white layer on your face - this is the dreaded white cast.