Product formulas and ingredient lists
Product-to-ingredient mappings are built from brand-published ingredient lists — the INCI list printed on packaging or published on an official brand or retailer product page. List order is recorded where available, since concentration is broadly regulated to correlate with listed position for ingredients above roughly 1%. List order is not a measured percentage, and it is not disclosed for lower-concentration ingredients.
Ingredient identity and function
Ingredient names, INCI names, and general function categories (humectant, emollient, exfoliant, and so on) draw on standard cosmetic-ingredient naming conventions and published cosmetic chemistry references, cross-checked against how the ingredient actually appears on product labels.
Interaction notes
Ingredient-to-ingredient interaction notes are only published once a specific source has been checked for direct relevance to that pairing — a general article about exfoliation is not treated as evidence for a specific acid-and-retinoid note, for example. Every published interaction links its source and carries a confidence level rather than a flat safe/unsafe label.
Editorial guides and concern pages
K-Beauty 101 guides and concern pages cite the sources they draw on inline, and lean on regulatory and dermatological consumer-facing resources — for example the U.S. FDA's cosmetics guidance and the American Academy of Dermatology's consumer resources — for general skin-safety context, alongside brand and ingredient-manufacturer published information for K-Beauty-specific trend and formulation context.
What we don't do
We don't scrape user-generated reviews to infer safety or efficacy claims, and we don't treat marketing copy alone as evidence for an interaction or a health-related claim. If a record can't be traced to one of the categories above, it stays unpublished rather than shipping with a guessed source.