Roihi-Tsuboko (ロイヒつぼ膏): ingredients, dose and warnings in English

Roihi-Tsuboko (ロイヒつぼ膏) is sold in Japan as a class 3 medicine: the box reads 第3類医薬品. In 100 g of plaster mass: Methyl Salicylate 7.17 g, l-Menthol 3.25 g, Mentha Oil 0.35 g, dl-Camphor 2.51 g, Thymol 0.05 g, 4-Hydroxy-3-methoxybenzyl Nonylic Acid Amide 0.03 g. The package insert says: Peel the plaster surface of ROIHI-TSUBOKO™ off the film and apply it to the affected area.

Updated October 3, 2026

第3類医薬品On the box

第3類医薬品 · Class 3

What is in Roihi-Tsuboko

The package insert lists 6 active ingredients in 100 g of plaster mass. The middle column is how each one is written on the Japanese box.

Roihi-Tsuboko: active ingredients in 100 g of plaster mass, from the Japanese package insert
Ingredient	Name on the box	Amount
Methyl Salicylate	サリチル酸メチル	7.17 g
l-Menthol	l-メントール	3.25 g
Mentha Oil	ハッカ油	0.35 g
dl-Camphor	dl-カンフル	2.51 g
Thymol	チモール	0.05 g
4-Hydroxy-3-methoxybenzyl Nonylic Acid Amide	ノニル酸ワニリルアミド	0.03 g

Additives, as written on the package insert (Japanese)

生ゴム、ポリイソブチレン、ポリブテン、石油系樹脂、BHT、重質炭酸カルシウム、カーボンブラック、三二酸化鉄、赤色227号、その他1成分

Source: PMDA (Pharmaceuticals and Medical Devices Agency) — ロイヒつぼ膏: package insert (添付文書)

What the package insert lists it for

The approved wording of the Japanese package insert, translated. It is what the product is sold for, not advice on what to take.

Stiff shoulders, lower back pain, bruises, sprains, joint pain, muscle pain, muscle fatigue, chilblains

The dose, as written on the package insert

Translated line by line from the directions and dosage (用法・用量) section.

On the box: 第3類医薬品

Peel the plaster surface of ROIHI-TSUBOKO™ off the film and apply it to the affected area.

Notes on the directions

(1) When letting children use it, have them use it under the guidance and supervision of a parent or guardian.
(2) If you have sensitive skin, before use apply a small piece, about 1 cm square as a guide, to the inside of your arm for half a day or longer, and use it only after checking that symptoms such as rash/redness, itching or skin irritation do not appear.
(3) Wipe off sweat etc. well and clean the affected area before applying it.
(4) If you have sensitive skin, do not keep applying it to the same place.
(5) Depending on your constitution, skin irritation etc. may occur, so avoid applying it right after bathing.
(6) Use this product for external use only, and do not take it by mouth.
(7) Please be careful, as using it together with things that give off heat (kotatsu heated tables, heated carpets, heat packs, electric blankets, etc.) may make the irritation stronger.

Do not

The package insert opens with what you must not do.

(If you do not follow these, your current symptoms may get worse, and side effects become more likely)

1. Do not use it on the following areas.

(1) Around the eyes, mucous membranes, etc. (2) Eczema, skin irritation, wounds.

Ask a doctor, pharmacist or registered salesperson

The package insert says to ask for advice in these cases.

1. If you are one of the following people, ask a doctor, pharmacist or registered salesperson for advice before using it.

(1) People who are, or whose family members are, prone to allergies.
(2) People who have had allergic symptoms (for example, rash/redness, itching, skin irritation, etc.) caused by medicines etc.

2. If the following symptoms appear after using it, they may be side effects, so stop using it immediately and ask a doctor, pharmacist or registered salesperson for advice, taking this leaflet with you.

Possible side effects, by part of the body

Skin: rash/redness, itching, swelling, skin irritation, pigmentation, peeling of the skin, pain, etc.

3. If your symptoms do not improve after using it for 5 to 6 days, stop using it and ask a doctor, pharmacist or registered salesperson for advice, taking this leaflet with you.

Other precautions

■ Other precautions
When bathing, the place where it was applied may sting, so always peel it off about 30 minutes to 1 hour beforehand. Do not bathe with it still on.

Who can sell it in Japan

The Roihi-Tsuboko box carries the class 第3類医薬品, which decides who may sell it.

On the box: 第3類医薬品 (Class 3). The box reads 第3類医薬品.
Who can sell it: A pharmacist or a registered salesperson may sell it.

The five classes on Japanese medicine boxes, side by side

Source: e-Gov law search (Digital Agency, Japan) — Pharmaceutical and Medical Device Act (医薬品医療機器等法), current text · e-Gov law search (Digital Agency, Japan) — Enforcement Regulations of the Pharmaceutical and Medical Device Act (施行規則), current text · Ministry of Health, Labour and Welfare — Classes of medicine and how they are sold (参考資料, 6 March 2026)

Taking it home

Taking Japanese medicine home: the limits in South Korea, Taiwan, mainland China and Hong Kong

Frequently asked questions

Do I need a pharmacist to buy Roihi-Tsuboko?

Roihi-Tsuboko is a class 3 medicine (第3類医薬品). A pharmacist or a registered salesperson may sell it.

What is Roihi-Tsuboko called in Japanese?

ロイヒつぼ膏. The Roihi-Tsuboko box also carries the class 第3類医薬品.