Quick answer
Confused by INCI, BHA, humectant, fungal acne, “non-comedogenic”? This bilingual glossary explains 50 essential skincare terms in plain language.
Want the authentic one? Every product on TheSkinProof is invoice-verified.
Shop all verified products →Skincare has its own language, and the jargon stops a lot of people from building a good routine. Here are 50 essential terms, explained simply. Bookmark this and refer back any time. For how the actives work together, see ingredient layering, and the full authentic-skincare guide.
Skin & barrier basics
- Skin barrier — the outer layer that keeps moisture in and irritants out. Repair it with ceramides.
- Sebum — the skin’s natural oil.
- Sebaceous glands — glands that produce sebum.
- pH — acidity level; healthy skin is slightly acidic (~4.7–5.5).
- Microbiome — the community of good bacteria living on skin.
- TEWL (trans-epidermal water loss) — water escaping through a weak barrier.
- Dehydrated skin — lacking *water* (a condition); different from dry skin (lacking *oil*).
- Comedone — a clogged pore; open = blackhead, closed = whitehead.
Ingredient types
- Active — an ingredient that creates a measurable change (e.g. retinol, acids).
- Humectant — draws in water (e.g. hyaluronic acid, glycerin).
- Emollient — softens and smooths skin (e.g. squalane).
- Occlusive — seals moisture in (e.g. petrolatum, shea).
- Antioxidant — neutralizes free radicals (e.g. vitamin C).
- AHA — water-soluble acid for surface exfoliation (glycolic, lactic).
- BHA — oil-soluble acid that works inside pores (salicylic acid).
- PHA — a gentler exfoliating acid for sensitive skin.
- Retinoid / retinol — vitamin A derivative for ageing and acne.
- Niacinamide — vitamin B3; oil control, pores, brightening (guide).
- Peptides — amino-acid chains that support firmness.
- Ceramides — barrier-repairing lipids.
- Centella / Cica — soothing botanical (guide).
- Azelaic acid — acne + redness + dark spots (guide).
- Alpha-arbutin — brightening, fades dark spots.
- Tranexamic acid — targets stubborn pigmentation.
- Snail mucin — hydrating, repairing K-beauty ingredient.
Concerns & conditions
- Acne — clogged, inflamed pores (guide).
- Fungal acne (malassezia folliculitis) — yeast-driven bumps; needs different care than normal acne.
- Hyperpigmentation — dark patches from excess melanin.
- PIH (post-inflammatory hyperpigmentation) — dark marks left after acne; common on brown skin.
- Melasma — hormonal/sun-driven symmetrical patches (guide).
- Rosacea — chronic facial redness.
- Keratosis pilaris — rough “chicken skin” bumps on arms.
- Purging — temporary breakout when starting an active that speeds cell turnover.
- Breakout / reaction — irritation or clogging from an unsuitable product (not purging).
Product & label terms
- INCI — the standardized ingredient list on every product.
- Non-comedogenic — formulated not to clog pores.
- Fragrance-free vs unscented — free of added scent vs scent-masked.
- Broad-spectrum — sunscreen protecting from UVA + UVB.
- SPF — sunburn (UVB) protection rating.
- PA+ rating — UVA protection level (more + = more protection).
- Patch test — applying a product to a small area first to check for reaction.
- Double cleansing — oil cleanser then water-based cleanser (great for sunscreen/makeup).
- Slugging — sealing the routine with an occlusive overnight.
- Batch code — manufacturing code used to verify authenticity & expiry (how to check).
- PAO (period after opening) — the “6M/12M” jar symbol = months usable after opening.
Authenticity terms (Bangladesh)
- Counterfeit / fake — an illegal copy of a brand product.
- First copy / replica / master copy — all names for counterfeits (explained).
- Grey market — genuine product imported through unofficial channels (no warranty, storage unknown).
- Invoice-verified — matched to its importer invoice to prove origin (what it means).
- BSTI — Bangladesh Standards & Testing Institution; sets product safety standards.
Know the words, dodge the fakes. Every product at TheSkinProof is invoice-verified and batch-checked, with a 2× money-back guarantee. Browse verified products.
Frequently asked questions
What does “non-comedogenic” mean?
It means a product is formulated not to clog pores — useful for oily and acne-prone skin. It’s a formulation goal, not a guarantee, so individual results can still vary.
What is the difference between dry and dehydrated skin?
Dry skin lacks oil (a skin type); dehydrated skin lacks water (a temporary condition any skin type can have). Dehydrated skin needs humectants like hyaluronic acid, not just heavy oils.
What does “invoice-verified” mean for skincare?
It means each product is matched to its importer invoice to prove it entered the country legally and authentically. TheSkinProof invoice-verifies and batch-checks every product it sells.
What does "combination skin" mean?
Combination skin means some areas, usually the T-zone, run oilier while the cheeks stay drier or normal, so using different products by zone often works better.
What does "invoice-verified" mean when buying skincare?
It means the product is matched against the importer's invoice and batch number before being listed, which lowers the chance of buying something grey-market or fake.