Korean Skincare Expiration Dates: How to Read the Label

You turn over a Korean toner, spot 2028.05.14, and wonder whether you are looking at its birthday or its deadline. Then there is a tiny open jar marked 12M. Which one should you follow?

Read the word beside the date first. 사용기한 means use-by date; 제조일자 means manufacturing date. An open-jar 12M symbol means 12 months after opening. When your package gives both an expiration date and an opening period, keep track of both and use the earlier limit unless the manufacturer gives different instructions.

Here is how to read Korean skincare expiration dates and decide what to do with the bottle you actually bought, with examples from COSRX and Beauty of Joseon.

The Korean words to look for

Check the carton, bottle base, and sealed end of a tube. Use the wording on your own package; a date without a label can be ambiguous.

Marking	English meaning	How to read it
사용기한	Use-by date	The date limits how long to keep the product under its stated conditions.
제조일자 / 제조	Manufacturing date / manufactured	This tells you when it was made. You still need its use-by or opening instructions.
개봉 후 사용기간	Period after opening	Count from the day you first open it.
제조번호 / LOT	Manufacturing batch number	Keep this for a question or complaint to the brand. It is not automatically a readable date.
까지	Until / by	Following a date, it indicates the endpoint.

These are translations, not photographs of a particular product label. Korea’s Ministry of Food and Drug Safety packaging guide lists a manufacturing number and a use-by date or period after opening among cosmetic labeling information. That is why a batch code and an expiration date can appear beside one another without meaning the same thing.

Read the year before the month

For a date printed in YYYY.MM.DD format, 2028.05.14 means May 14, 2028. The four-digit year comes first, followed by the month and day. Do not automatically read it as the U.S. month/day/year format.

Compare these invented labels:

Example label	What it tells you	What it does not tell you
사용기한 2028.05.14	Use-by: May 14, 2028	How long an opened bottle lasts, if a separate opening period applies
제조일자 2026.05.14	Made: May 14, 2026	Its expiration date; do not add three years without brand instructions
LOT A26B14	A batch identifier	A reliable date you can decode by treating the letters as months

If the label gives only a two-digit year or an unexplained sequence, ask the brand to interpret it. Guessing becomes especially unhelpful when the box, store listing, and bottle use different formats.

What the open jar marked 12M means

The open-jar symbol is often called PAO, short for period after opening. 6M means six months, 12M means 12, and 24M means 24. It describes the time after opening, rather than the time since delivery. The symbol and its meaning appear in Article 19 and Annex VII of the EU cosmetics regulation, which helps explain why you see it on international packaging.

Put a small dated sticker on the container when you open it. Keep the carton until you have recorded the date and batch details. This takes seconds and saves a lot of guessing six months later.

Two dates, one practical example

Suppose a hypothetical cream says EXP 2028.05.14 and 12M.

You open it on	Twelve months later	Earlier limit to record
September 7, 2026	September 7, 2027	September 7, 2027
February 1, 2028	February 1, 2029	May 14, 2028

Opening an older bottle does not reset its printed expiration date. These examples explain how to manage two instructions; they are not shelf-life tests or a guarantee that every cream stays usable until the calculated day.

COSRX and Beauty of Joseon: check the specific product

The familiar “three years unopened, one year opened” advice has a basis in some brands’ guidance. It still has exceptions.

Official source checked September 7, 2026	What the brand says	What that means for your purchase
COSRX general FAQ	Most products: three years unopened at room temperature; usually 12 months after opening, with exceptions	Check the bottle and individual product instructions before using this as a default.
COSRX Advanced The Vitamin C 23 Serum	24 months from manufacture or two months after opening; the page instructs refrigeration at 3–10°C (about 37–50°F)	This serum needs a much shorter opening reminder than the general brand FAQ suggests.
Beauty of Joseon regional product FAQ	Three years unopened from manufacture and 12 months after opening; recommends finishing within 6–12 months once opened	Use your product’s package and market-specific directions if they differ from the general FAQ.

The vitamin C example is the useful one to remember. A recommendation for most of a brand’s range should not override a shorter instruction for a particular formula. Check the exact version, too; reformulations can change directions.

If you already have the COSRX Snail 96 Essence on your shelf, read its own package instead of borrowing the vitamin C serum’s storage instructions. Different formulas can need different handling even when their logos match.

Why a U.S. package may look different

The FDA says ordinary cosmetics do not generally have to carry an expiration date under U.S. law. Manufacturers are still responsible for safety. A missing date on an American cosmetic is therefore different from an unreadable date on a Korean product that normally prints one.

The FDA also reviews imported cosmetic labeling for required English information. An English sticker on imported packaging is not, by itself, proof of a counterfeit. Equally, a tidy sticker or a working barcode does not establish authenticity.

Sunscreen needs separate attention because U.S. rules treat it as a drug. Read the actual version’s expiration date and directions; do not use the general cosmetic discussion here to extend a sunscreen’s stated life.

A batch number is useful, but it is not proof of authenticity

COSRX’s official FAQ links to its own verification service using the batch number and expiration date. Start from that brand page rather than an unfamiliar checker that asks for personal information.

Beauty of Joseon takes a different approach. Its regional FAQ says it cannot establish authenticity from photos, videos, or lot numbers for purchases from unauthorized sellers. It also says its QR authentication app was suspended and those code seals are being phased out. A missing QR seal alone therefore does not settle the question.

For an unclear date, a useful message to the seller is:

Could you confirm whether the marking in this photo is the manufacturing date or expiration date? Please also confirm the recommended period after opening for this exact product version.

Include the product name, size, seller, and clear label photos. Keep the order number for the retailer’s own support channel. If you are choosing where to order next, our Olive Young shopping guide covers the differences between its U.S. and Global stores.

Before you open a backup bottle

A multipack only saves money when you can finish it. Imagine that your current bottle will last until December, but its unopened backup expires in January. The backup may leave very little usable time even though it was sealed when it arrived.

Before opening it, record the printed expiration date, opening period, and any special storage instruction. Compare that with when you expect to start using it. Ask about dates before buying clearance stock, especially when buying several bottles of the same treatment.

Store products as directed. The FDA notes that heat, moisture, air, and handling can affect a cosmetic’s condition; an unexpected smell, color change, or separation is a reason to stop and check with the brand. A normal appearance cannot prove that an expired or badly stored product is still suitable.

The most useful label habit is a simple note: opened date, printed expiry, and product-specific instructions. Once you have those three, you can decide what to use next without trying to decode every number on the carton.

Header image: AI-generated illustration. The packages are fictional and do not show real product labels.

Prepared by K-Glow Insider. Sources checked September 7, 2026. The dates in the worked examples are illustrative; the brand guidance is linked beside each claim. This is a label-reading guide, not a personal product wear test. See how we prepare our guides.