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
1. Skin barrier — the outer layer that keeps moisture in and irritants out. Repair it with ceramides.
2. Sebum — the skin’s natural oil.
3. Sebaceous glands — glands that produce sebum.
4. pH — acidity level; healthy skin is slightly acidic (~4.7–5.5).
5. Microbiome — the community of good bacteria living on skin.
6. TEWL (trans-epidermal water loss) — water escaping through a weak barrier.
7. Dehydrated skin — lacking *water* (a condition); different from dry skin (lacking *oil*).
8. Comedone — a clogged pore; open = blackhead, closed = whitehead.
Ingredient types
9. Active — an ingredient that creates a measurable change (e.g. retinol, acids).
10. Humectant — draws in water (e.g. hyaluronic acid, glycerin).
11. Emollient — softens and smooths skin (e.g. squalane).
12. Occlusive — seals moisture in (e.g. petrolatum, shea).
13. Antioxidant — neutralizes free radicals (e.g. vitamin C).
14. AHA — water-soluble acid for surface exfoliation (glycolic, lactic).
15. BHA — oil-soluble acid that works inside pores (salicylic acid).
16. PHA — a gentler exfoliating acid for sensitive skin.
17. Retinoid / retinol — vitamin A derivative for ageing and acne.
18. Niacinamide — vitamin B3; oil control, pores, brightening (guide).
19. Peptides — amino-acid chains that support firmness.
20. Ceramides — barrier-repairing lipids.
21. Centella / Cica — soothing botanical (guide).
22. Azelaic acid — acne + redness + dark spots (guide).
23. Alpha-arbutin — brightening, fades dark spots.
24. Tranexamic acid — targets stubborn pigmentation.
25. Snail mucin — hydrating, repairing K-beauty ingredient.
Concerns & conditions
26. Acne — clogged, inflamed pores (guide).
27. Fungal acne (malassezia folliculitis) — yeast-driven bumps; needs different care than normal acne.
28. Hyperpigmentation — dark patches from excess melanin.
29. PIH (post-inflammatory hyperpigmentation) — dark marks left after acne; common on brown skin.
30. Melasma — hormonal/sun-driven symmetrical patches (guide).
31. Rosacea — chronic facial redness.
32. Keratosis pilaris — rough “chicken skin” bumps on arms.
33. Purging — temporary breakout when starting an active that speeds cell turnover.
34. Breakout / reaction — irritation or clogging from an unsuitable product (not purging).
Product & label terms
35. INCI — the standardized ingredient list on every product.
36. Non-comedogenic — formulated not to clog pores.
37. Fragrance-free vs unscented — free of added scent vs scent-masked.
38. Broad-spectrum — sunscreen protecting from UVA + UVB.
39. SPF — sunburn (UVB) protection rating.
40. PA+ rating — UVA protection level (more + = more protection).
41. Patch test — applying a product to a small area first to check for reaction.
42. Double cleansing — oil cleanser then water-based cleanser (great for sunscreen/makeup).
43. Slugging — sealing the routine with an occlusive overnight.
44. Batch code — manufacturing code used to verify authenticity & expiry (how to check).
45. PAO (period after opening) — the “6M/12M” jar symbol = months usable after opening.
Authenticity terms (Bangladesh)
46. Counterfeit / fake — an illegal copy of a brand product.
47. First copy / replica / master copy — all names for counterfeits (explained).
48. Grey market — genuine product imported through unofficial channels (no warranty, storage unknown).
49. Invoice-verified — matched to its importer invoice to prove origin (what it means).
50. 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.
Before you buy: check authenticity, not price
Don’t chase the cheapest product — look for the authentic one. A cheap fake can damage your skin, and using nothing at all does less harm than using a counterfeit. But a high price doesn’t guarantee authenticity either — people overpay for fakes too. So judge by authenticity, not price.
TheSkinProof offers free authenticity verification. Message our Facebook page with the product and we’ll analyze it and tell you whether it’s real or fake — so it’s important to verify before you buy anything. Or simply buy from TheSkinProof, where every product is already invoice-verified with a 2× money-back guarantee.