Pillar I · COSRX Batch Code Checker
COSRX Batch Code Checker — lot number & freshness guide
Lot Stamp (Date Not Encoded) · [Lot number, 3–12 letters or digits][Production date not publicly encoded] · checked privately in your browser.
Lot Stamp (Date Not Encoded) · Houses without a published date code
[Lot number, 3–12 letters or digits][Production date not publicly encoded] · e.g. L24105
Where COSRX stamps its code: outer box base crimp + flacon base
Ink-jet printed on the bottom base of Advanced Snail 96 Mucin Power Essence and BHA Blackhead Power Liquid pump bottles, embossed on the top crimp of Low pH Good Morning Gel Cleanser tubes, and printed on the bottom of the outer box.
- Read the code off the box base crimp in raking light — authentic embossing has uniform depth.
- Read the flacon base or label code and enter it above — the two must match character for character.
- Check for scraped, re-embossed or stickered-over crimps: a classic way to hide aged gray-market stock.
Printable guideWhere to Find Your Code (Tap to Zoom) ↓ Download WebP
Parent Conglomerate Pattern · Houses without a published date code
How COSRX Codes Are Structured
- Pattern
- Lot Stamp (Date Not Encoded)
- Group
- Houses without a published date code
- Structure
- [Lot number, 3–12 letters or digits][Production date not publicly encoded]
- Length
- 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 characters
- Stamped On
- outer box base crimp · flacon base
- Confidence
- Reference only — the code identifies the production lot, but no production date can be read from it. Use the printed EXP / MFD date or the PAO symbol, or ask the brand to date the lot number.
- Reported Notes
- COSRX products print a 4-to-8-character alphanumeric factory lot code alongside an explicit Korean YYYY.MM.DD manufacture (제조) and expiration (사용기한 / 까지) date on the base of every bottle and tube crimp. Unopened snail mucin essences, cleansers, and sunscreens last 36 months from manufacture; observe the 12M PAO symbol after opening. (reported, not verified by Beauty.net)
- Where to Look
- Ink-jet printed on the bottom base of Advanced Snail 96 Mucin Power Essence and BHA Blackhead Power Liquid pump bottles, embossed on the top crimp of Low pH Good Morning Gel Cleanser tubes, and printed on the bottom of the outer box.
Worked Decode · L24105 → Not date-encoded
| Sample Code | Production Date | Verdict (as of November 2026) |
|---|---|---|
| L24105 | Not date-encoded | Lot Recorded — Check the Printed Date |
| 3145A | Not date-encoded | Lot Recorded — Check the Printed Date |
| B2209A | Not date-encoded | Lot Recorded — Check the Printed Date |
COSRX has not published how its lot code encodes the production date, so no date is estimated. Read the printed EXP / MFD date or the PAO (open-jar) symbol, or give the lot number to the brand's customer service.
Beauty.net does not estimate dates for houses without a published code structure. Reported notes: batch-code reference, not verified by Beauty.net. A valid format never proves authenticity.
Searchable in the Decoder
Popular COSRX Products
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- cosrx snail mucin
- cosrx advanced snail 96 mucin power essence
- cosrx low ph good morning gel cleanser
- cosrx bha blackhead power liquid
- cosrx acne pimple master patch
Section V · Formulation Audit
Audited Formulations From COSRX
-
Advanced Snail 96 Mucin Power Essence →
Barrier / Peptide / Hydrator · Essence / Barrier Serum
Skincare is best used within about 36 months of production and 6–12 months of opening.
-
The 6 Peptide Skin Booster Serum (Copper Tripeptide-1 + Argireline + NAG) →
Barrier / Peptide / Hydrator · Multi-Peptide & Amino Acid First-Step Toner-Serum
Skincare is best used within about 36 months of production and 6–12 months of opening.
Field Notes
Frequently Asked Questions
Can I decode a COSRX batch code?
COSRX has not published how its lot code encodes the production date, so Beauty.net records the lot number and checks its format but does not estimate a date. Reported notes (from the batch-code reference cited below, not verified by Beauty.net): COSRX products print a 4-to-8-character alphanumeric factory lot code alongside an explicit Korean YYYY.MM.DD manufacture (제조) and expiration (사용기한 / 까지) date on the base of every bottle and tube crimp. Unopened snail mucin essences, cleansers, and sunscreens last 36 months from manufacture; observe the 12M PAO symbol after opening. To check freshness, read the printed EXP or MFD date or the PAO (open-jar) symbol, or give the lot number to COSRX customer service. A correctly formatted code never proves authenticity.
Where is the batch code stamped on a COSRX box and bottle?
Ink-jet printed on the bottom base of Advanced Snail 96 Mucin Power Essence and BHA Blackhead Power Liquid pump bottles, embossed on the top crimp of Low pH Good Morning Gel Cleanser tubes, and printed on the bottom of the outer box. Look on the outer box base crimp and the flacon base. The code on the box and the code on the flacon must match character for character; a scraped, re-embossed or stickered-over box crimp is a classic sign of aged gray-market stock.
How long does COSRX last and where can I buy fresh-batch authentic products in Singapore?
Unopened, COSRX skincare is a fresh batch for 24 months from production and should be used within about 36 months, as vitamin C, retinoids and peptides degrade with time. In Singapore, buy from COSRX authorised counters and the brand's official online store, and check that the printed EXP / MFD date is recent before you pay.