Methodology

Two kinds of statements: L0 and L1

L0: what the label function is

Plain descriptions of what an ingredient is used for in a product, such as "holds water" or "softens the skin". These do not claim a research result, so they carry no citation.

L1: research reported

Any sentence that says a study found something must start with wording like "Studies report" and must have a matching entry in the Sources list on the same page. A sentence without a source is not published.

Nothing stronger is allowed. Words about curing, treating, or guaranteeing results are blocked by an automated check, and the build fails if one slips in.

Source rules

• Allowed: PubMed or DOI records, government and standards bodies (named with their country, such as Korea MFDS, US FDA, Japan MHLW, EU CosIng), safety panels such as US CIR and EU SCCS, and textbooks cited with edition and page.
• Manufacturer data is never the only source for a claim.
• Each source is marked human, lab (in vitro), or animal. Lab and animal results are labeled "lab tests, not on people".
• Sources are dated 2005 or later, unless the source is a landmark paper and the page says so.
• Links are checked when the site is built. A dead link is flagged for me to fix.

Three-country regulation

Each page shows the status of the ingredient or product in Korea (MFDS), the United States (FDA), and Japan (MHLW). The same ingredient can be allowed in one country, limited in another, and not evaluated in a third.

A status is a legal fact about one market. It is not a safety verdict, and it does not carry over to another country. Pages never use one country's status to speak for the others.

The caution block

The caution block covers five groups: pregnancy and breastfeeding, people who take medicines, eczema or psoriasis, sensitive or acne-prone skin, and teens. A group appears only when the label gives a reason. Each one is marked Avoid, Ask first, or Usually fine, and carries a source when one exists.

The "My situation" panel in the page header lets you tick the groups that apply to you. Your choices are saved in your own browser and nowhere else.

What the byline means

Reviewed by Pharmacist Choi (licensed in Korea)

It means I read every sentence on the page against its source and removed or rewrote what the source did not support. It is a statement about the text. It is not an endorsement of the product, and it does not mean the product suits you.

Why there are no rankings or scores

Whether a product suits you depends on your skin, your medicines, and whether you are pregnant. A page cannot see any of that. A ranking would hide the facts that matter and would make the site look like a store. So these pages explain the label and leave the choice to you and the pharmacist or doctor you talk to.

Known limits

• Ingredient lists come from the seller's public page and can differ from the box in your hand. Check the package.
• The label rarely states how much of an ingredient is inside. Pages say "not disclosed" instead of guessing.
• Rules change. Each page shows its review date; a page older than a year should be treated as due for another look.