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Dextromethorphan in Japan (the cough ingredient of NyQuil and Robitussin)

Dextromethorphan: how it is named on Japanese boxes, the 2 products in this database that contain it, how their doses compare with US labels, and the rules for bringing it into Japan and taking it home. On 3 October 2026, PMDA's search of OTC package inserts returned 169 products containing dextromethorphan.

Updated

169OTC products in PMDA search
2In this database

要確認 ingredient

What it is called on Japanese boxes

How dextromethorphan is written on Japanese boxes, with the official English name from the JAN database or the Japanese Pharmacopoeia.

Dextromethorphan: official names in Japan (JAN database and Japanese Pharmacopoeia, checked 3 October 2026)
Official English nameName on Japanese boxesListed in
Dextromethorphan Hydrobromide Hydrateデキストロメトルファン臭化水素酸塩水和物JAN

Dextromethorphan in Japanese products

The amount of dextromethorphan per dose and per day, as each package insert sets it.

On 3 October 2026, PMDA's search of OTC package inserts returned 169 products containing dextromethorphan.

Dextromethorphan in Japanese OTC medicines in this database, from each package insert (PMDA, checked 3 October 2026)
ProductAmountMost a day for adultsClass on the box
SS Bron Solution L10 mg per dose of 5 mL60 mg (6 doses a day)第2類医薬品
S.Tac General Cold Medicine16 mg per dose of 3 tablets48 mg (3 doses a day)第②類医薬品

Most a day for adults, by the package insert (mg)

SS Bron Solution L60 mg
S.Tac General Cold Medicine48 mg

Each package insert sets its own dose. Follow the directions and dosage on the box you buy.

Japanese doses and US labels

US doses come from the OTC labels on DailyMed.

Dextromethorphan: Japanese package inserts and US OTC labels side by side (PMDA and DailyMed, checked 3 October 2026)
ProductWhereAmountMost a day for adults
SS Bron Solution LJapan, package insert10 mg per dose of 5 mL60 mg (6 doses a day)
S.Tac General Cold MedicineJapan, package insert16 mg per dose of 3 tablets48 mg (3 doses a day)
NyQuil Cold & Flu liquidUS, OTC label30 mg per 30 mL dose cup120 mg (4 doses in 24 hours)
DayQuil Cold & Flu liquidUS, OTC label10 mg per 15 mL80 mg (4 doses in 24 hours)
Robitussin Maximum Strength Cough + Chest Congestion DMUS, OTC label20 mg per 20 mL120 mg (6 doses in 24 hours)

Follow the directions and dosage exactly.That is the wording of the Japanese package inserts. The table lines up what each product's own directions say; it is not a guide to how much to take.

The directions on the US labels, as printed

NyQuil Cold & Flu liquid: directions for adults (DailyMed, US label)adults & children 12 yrs & over: 30 mL every 6 hrs / do not exceed 4 doses per 24 hrsDailyMed
DayQuil Cold & Flu liquid: directions for adults (DailyMed, US label)adults & children 12 yrs & over: 30 mL every 4 hrs / do not exceed 4 doses per 24 hrsDailyMed
Robitussin Maximum Strength Cough + Chest Congestion DM: directions for adults (DailyMed, US label)adults and children 12 years and over: 20 ml every 4 hours / do not take more than 6 doses in any 24-hour periodDailyMed

Bought with a check in Japan (要確認)

From 1 May 2026, medicines taken by mouth that contain dextromethorphan are designated abuse-prevention medicines (指定濫用防止医薬品).

Bringing it into Japan

Medicine with dextromethorphan that you bring for your own use counts towards Japan's supply limits for medicine.

Taking it home

What the official customs pages say about dextromethorphan. Check them before you fly.

  • South Korea: The Korea Customs Service lists codeine and dihydrocodeine as narcotics, and allylisopropylacetylurea, bromovalerylurea and dextromethorphan as psychotropic drugs. The Korea Customs Service's press release of 17 July 2025 gives, as examples, Japanese painkillers containing the psychotropic drug allylisopropylacetylurea, US cold medicines containing dextromethorphan and supplements containing melatonin, and says these medicines and foods are banned from being brought into Korea.
  • Mainland China: Dextromethorphan has been a class 2 psychotropic drug in China since 1 July 2024.

Source: Korea Customs Service — Narcotics and psychotropic ingredients (마약류 성분 목록) · Korea Customs Service — Press release, 17 July 2025 (보도자료) · Korea Customs Service — Check the ingredients of medicine you bring in (의약품 성분 확인) · National Medical Products Administration (NMPA) — Notice adding dextromethorphan to class 2 psychotropic drugs (7 May 2024)

Frequently asked questions

Is dextromethorphan sold over the counter in Japan?

On 3 October 2026, PMDA's search of OTC package inserts returned 169 products containing dextromethorphan. In this database: SS Bron Solution L, S.Tac General Cold Medicine.

How much Dextromethorphan Hydrobromide Hydrate is in SS Bron Solution L?

10 mg per dose of 5 mL, and at most 60 mg (6 doses a day) by its package insert.

How does SS Bron Solution L compare with NyQuil Cold & Flu liquid?

SS Bron Solution L: 10 mg per dose of 5 mL, at most 60 mg (6 doses a day) (Japanese package insert). NyQuil Cold & Flu liquid: 30 mg per 30 mL dose cup, at most 120 mg (4 doses in 24 hours) (US label). Each product's directions apply only to that product.

Why does a Japanese shop check before selling dextromethorphan?

From 1 May 2026, medicines containing any of 8 ingredients are designated abuse-prevention medicines (指定濫用防止医薬品): ephedrine, codeine, dihydrocodeine, diphenhydramine, dextromethorphan, pseudoephedrine, bromovalerylurea and methylephedrine, with their hydrates and salts. Medicines for external use are not included.

Related items

PMDA package insert search (Japanese)

Sources for this page

Back to Japanese OTC medicine

Compiled by Japan Japan !! · Updated October 3, 2026