Value Village ／ Beauty
This answer is a draft. It stays unpublished until legal review and source verification are complete.
The difference between an antiperspirant and a deodorant is one of the most-asked questions on overseas Q&A sites. In Japan the two fall into separate legal categories — quasi-drug and cosmetic — and you can tell them apart from the packaging. This article explains how to read the label at the drugstore (Matsumoto Kiyoshi, Welcia, etc.) and what the common myths get wrong.
| Category | Label | What it may claim | Typical ingredients |
|---|---|---|---|
| Quasi-drug ("medicated") | The quasi-drug label (医薬部外品) printed on the package | May claim to reduce sweat and prevent odour | Antiperspirant agents (e.g. aluminium chlorohydrate), antibacterial agents |
| Cosmetic | No category shown, or "cosmetic" (化粧品) | Within the 56 items, e.g. cleanses the skin, masks odour with fragrance | Fragrance, absorbent powders, etc. |
A quasi-drug contains an active ingredient approved by the Ministry of Health, Labour and Welfare, and "prevention of underarm odour (wakiga)" and "antiperspirant" are recognised claims. A cosmetic may not make these claims.
[Verify] Check the categories and the scope of claims against the MHLW's "Scope of efficacy claims for quasi-drugs" and notice Yakushoku-hatsu 0721 No. 1.
Antiperspirant agents temporarily block the openings of the sweat glands; used on limited areas, the effect on temperature regulation is generally described as small. They are, however, not meant for use over the whole body. If you are concerned, ask a dermatology clinic (covered by Japanese health insurance).
On the link between antiperspirant aluminium compounds and breast cancer or dementia, several bodies including the American Cancer Society (ACS) state that "no clear evidence has been established". The ingredients are approved actives in Japan too. Anyone still uneasy has the option of choosing a product in the cosmetic category.
Antiperspirant agents act on the sweat glands when you are sweating little. Applying at night, to dry skin after a bath, is generally described as working better, and "night application" is shared practice among people in Japan.
Over-spraying can cause cold injury (frostbite) to the skin through cooling, and the Consumer Affairs Agency has issued warnings about it. Do not spray the same spot continuously for more than a few seconds.
Skin just shaved or depilated is sensitive to irritation, and the product may sting or cause redness. Leave a gap to be safe.
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https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/kenkou_iryou/iyakuhin/keshouhin/index.html
https://www.mhlw.go.jp/file/06-Seisakujouhou-11120000-Iyakushokuhinkyoku/kesyouhin_hanni_20111.pdf
https://www.caa.go.jp/policies/policy/consumer_safety/caution/
⚠️ Editorial note: the source URLs above were identified by search. Our working environment cannot reach go.jp domains, so the contents have not been checked against the text. Verify every source before publication and record who checked it and when.
What we share here are ideas and everyday practices passed down among people living in Japan, together with general information drawn from public sources. They are not official recommendations, and they are not professional instruction. Practices vary between households and regions.
This is general information. Results vary from person to person and depend on your own conditions and surroundings.
Please decide for yourself, using your own judgement, whether any of this suits your situation. We cannot accept responsibility for any damage, loss or injury arising from following this article.
Cosmetics are not medicines and are not meant to diagnose, heal or prevent any condition. If your skin reacts, stop using the product and see a dermatologist.
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