Buying in Japan

How to Read the Back of a Japanese Medicine Box

Drug classes, expiry dates, ingredients, and warnings โ€” explained in plain English.

June 3, 2026 ยท 4 min read
Woman reading the back of a Japanese medicine box at a drugstore

The back of a Japanese medicine box follows a consistent layout. Once you know what the key labels mean, you can find the information you need in under a minute โ€” even without reading Japanese.

Here are the four sections worth knowing: the drug class label, the expiry date, the ingredients list, and the warnings.

1. The Drug Class Label (็ฌฌใ€‡้กžๅŒป่–ฌๅ“)

Drug class label on Japanese medicine box showing ็ฌฌ2้กžๅŒป่–ฌๅ“

Every medicine sold in Japan displays its drug class on the packaging โ€” usually on the front or side panel. The label reads ็ฌฌใ€‡้กžๅŒป่–ฌๅ“, where ใ€‡ is the class number.

Class 1ใ€€็ฌฌ1้กž

A pharmacist must be present and will confirm you've read the product information before completing the sale.

Class 2 ๏ผ Designated Class 2ใ€€็ฌฌ2้กž๏ผๆŒ‡ๅฎš็ฌฌ2้กž

Most everyday medicines โ€” cold tablets, allergy pills, pain relievers. No mandatory consultation required.

Class 3ใ€€็ฌฌ3้กž

Vitamins and mild supplements. The most straightforward to buy.

For the full breakdown โ€” including why a pharmacist sometimes stops you at the register โ€” read our guide to Japan's drug class system.

2. How to Find the Expiry Date (ไฝฟ็”จๆœŸ้™)

ไฝฟ็”จๆœŸ้™ expiry date label on Japanese medicine box

The expiry date is labeled ไฝฟ็”จๆœŸ้™ (shiyล kigen) and is usually printed on the side or bottom of the box. The format is YYYY.MM โ€” so 2028.09 means the medicine expires in September 2028.

๐Ÿ’ก Check the blister sheet too

Some medicines also print the expiry date directly on the PTP blister sheet โ€” the foil packaging the tablets come in. Not all medicines do this, but if you've already thrown away the box, it's worth checking.

Expiry date printed on PTP blister sheet of Japanese medicine

3. Reading the Ingredients List (ๆˆๅˆ†ใƒปๅˆ†้‡)

ๆˆๅˆ†ใƒปๅˆ†้‡ ingredients table on the back of a Japanese medicine box

The ingredients section is labeled ๆˆๅˆ†ใƒปๅˆ†้‡ and is laid out as a table. It's divided into two parts:

Active ingredients ๏ผˆๆœ‰ๅŠนๆˆๅˆ†๏ผ‰

Listed by name and amount in mg. These are the compounds that treat your symptoms โ€” for example, ibuprofen, acetaminophen, or cetirizine.

Inactive ingredients ๏ผˆๆทปๅŠ ็‰ฉ๏ผ‰

Fillers, binders, and coatings. Relevant if you have allergies to specific excipients.

Every product on OTC Guide Japan includes a full English translation of its ingredients and dosage. Search by medicine name to look one up.

4. Understanding the Warnings Section (ๆณจๆ„)

ๆณจๆ„ warnings section on Japanese medicine box showing ใ—ใฆใฏใ„ใ‘ใชใ„ใ“ใจ and ็›ธ่ซ‡ใ™ใ‚‹ใ“ใจ

The warnings section is labeled ๆณจๆ„ and is typically the largest section on the back of the box. Two subsections are the most important to check:

ใ—ใฆใฏใ„ใ‘ใชใ„ใ“ใจ โ€” Do not use if...

Hard contraindications. If any of these apply to you, do not take this medicine โ€” regardless of your symptoms. Common examples include specific drug allergies, asthma, kidney or liver disease, and pregnancy.

็›ธ่ซ‡ใ™ใ‚‹ใ“ใจ โ€” Consult before use if...

Situations where you should check with a pharmacist or doctor first โ€” such as being pregnant, elderly, or currently taking other medications.

The complete "do not use" and "consult before use" lists for every medicine on this site are translated into English. Find your medicine on OTC Guide Japan to check before you buy.

Frequently Asked Questions

What does ไฝฟ็”จๆœŸ้™ mean on a Japanese medicine box?

ไฝฟ็”จๆœŸ้™ (shiyล kigen) means "expiry date." It is printed in YYYY.MM format โ€” for example, 2028.09 means the medicine expires in September 2028.

What does ็ฌฌ2้กžๅŒป่–ฌๅ“ mean?

็ฌฌ2้กžๅŒป่–ฌๅ“ means "Class 2 OTC medicine." This category covers most everyday medicines โ€” cold tablets, allergy pills, and pain relievers. No pharmacist consultation is required to purchase them.

What is ๆˆๅˆ†ใƒปๅˆ†้‡ on a medicine box?

ๆˆๅˆ†ใƒปๅˆ†้‡ means "ingredients and amounts." It lists the active ingredients (ๆœ‰ๅŠนๆˆๅˆ†) by name and dosage in mg, followed by inactive ingredients (ๆทปๅŠ ็‰ฉ) such as fillers and binders.

What does ใ—ใฆใฏใ„ใ‘ใชใ„ใ“ใจ mean?

ใ—ใฆใฏใ„ใ‘ใชใ„ใ“ใจ means "things you must not do" โ€” in other words, hard contraindications. If any of the listed conditions apply to you, do not take the medicine. This is different from ็›ธ่ซ‡ใ™ใ‚‹ใ“ใจ, which lists situations where you should consult a pharmacist or doctor before use.

Where can I find English information on Japanese OTC medicines?

OTC Guide Japan provides English translations of ingredients, dosage, and warnings for medicines available at Japanese drugstores. Search by medicine name or category.

If you're unsure whether a medicine is right for you, speak with a pharmacist (่–ฌๅ‰คๅธซ) or registered salesperson (็™ป้Œฒ่ฒฉๅฃฒ่€…) at the drugstore. They can help guide you to the right product.