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Rohto Batch Codes: Year Digit + Month Letter (Unofficial)

Hada Labo, Melano CC, OXY and Sunplay follow an observed year-digit-plus-month-letter pattern that Rohto has never confirmed. We decode it, and we say so.

4 min read · Updated July 2026

Anatomy of the code 6C2

CharactersWhat they encode
6Last digit of the production year — 2026
CMonth letter: A = January … L = December, so C = March
2Production line — no date information

Worked examples

Decoded live by the same engine that powers the checker — not transcribed by hand.

6C2March 1, 2026low confidence

March 2026.

5H1August 1, 2025low confidence

H is the 8th letter — August 2025.

An observed pattern, not a published one

Rohto has never published a batch-code scheme. What exists is a pattern documented by the community across many products: a year digit, a month letter running A for January through L for December, then a line digit.

We decode it, and we label the result low-confidence — because it is a reading of a pattern rather than an application of a documented rule. That distinction matters more than a confident answer does.

Reading one by hand

  • First character: the year's last digit.
  • Second character: the month letter. A is January and L is December — all twelve letters are used, with no skips.
  • The result is a month, not a day.

FAQ

Should I trust this date?

Treat it as approximate. If the product carries a printed expiry date — many Japanese products do — use that instead.

Brands that use this code (4)

The format belongs to the manufacturer, not the label on the bottle — every brand below is stamped by the same plants and reads the same way.

Other code formats

Not sure which code on the pack is the batch code? How to Find Your Batch Code