Editorial policy
Every note names its sources, has its wording checked before it goes live, and shows under its title when it was last rechecked.
What order does a note follow?
- The first paragraph answers the question.
- A single table sums up the key facts.
- Situations, a morning and evening routine, and a checklist or log follow.
- Frequently asked questions and the list of sources close the note.
Only where a product is relevant does a note end with a checklist of ingredients to look for and at most one of the operator's products, described by facts such as ingredients, amounts, test results and price.
Which sources do we rely on?
- Guidance from medical societies and public agencies, and peer-reviewed studies. Every source is listed at the end of the note.
- Numbers keep the precision and units of the original source.
- Tests on a raw ingredient are never presented as results for a finished product; we say that they apply to the ingredient only.
- Videos and community posts only tell us what people are asking.
What do the evidence grades mean?
Under each title you will find the evidence mix, the review date and the next scheduled review, six months later.
| Label | Meaning |
|---|---|
| Evidence grade A | Mostly systematic reviews and randomized controlled trials |
| Evidence grade B | Mostly observational studies and small trials |
| Evidence grade C | Preliminary studies and ingredient-level tests |
| Evidence grade Institutional | Guidance from medical societies and public agencies |
| Evidence grade Mixed | Evidence across several grades |
| Evidence grade Limited evidence | General information |
Who writes and checks the notes?
Notes are written by KW Cosmetic Content Team. Each shows its author, first publication date and last update. We never display an expert review that did not take place.
How is the English edition made?
English notes are adapted from Korean notes on the same topic. Facts, figures and sources stay identical, while titles, headings and questions are rewritten in the words English-speaking readers search with.
How do we check wording?
Before publishing, we read every sentence against cosmetics labeling and advertising rules, including U.S., EU and UK rules for the English edition. Skin conditions are explained as information only, and no sentence suggests that a cosmetic treats, cures or prevents a disease. Situations that call for a doctor are spelled out inside the note.
How do we fix mistakes?
When new research appears or we find an error, we correct the note and update its last-updated date.We are still setting up a way to report errors.