Before a single tablet is pressed, a Japan-made supplement has to clear a question that has nothing to do with dose or evidence: is this ingredient, in this form, at this claim, legally a food at all? Japan answers that question through a system called shoku-yaku kubun (食薬区分), the food-medicine boundary, and it can stop a formula in its tracks regardless of how well established the ingredient is elsewhere.
This guide explains how the boundary works, the two official lists behind it, the four factors Japan weighs to make the call, and what it means for a brand ordering an export-only OEM product.
Health supplements are foods, not medicines, and are not a substitute for medical treatment.
💬 Not sure whether your ingredient can be made as a food in Japan? We check it against the current lists before formulation begins. See Japan-made supplement OEM.
What the food-medicine boundary is
Shoku-yaku kubun is Japan’s system for deciding whether a raw material may be sold as an ordinary food or must be treated exclusively as a pharmaceutical, based on a 1971 government notice still in use today.
Japan’s Pharmaceutical and Medical Device Act regulates medicines separately from food. Since a 1971 notice from the then Ministry of Health and Welfare (“無承認無許可医薬品の指導取締りについて”, Notice No. 476, 1 June 1971), the government has used a defined process to judge whether a given raw material, and a given product built from it, falls on the medicine side of that line or the food side. The Ministry of Health, Labour and Welfare (MHLW) maintains and periodically revises the lists that come out of this judgement.
The two lists behind the boundary
MHLW keeps one list of ingredients treated exclusively as medicines and one list of ingredients not treated as medicines unless a product markets them with a medicinal effect.
| List | What it means for a food product |
|---|---|
| ”Exclusively medicinal” ingredient list (専ら医薬品として使用される成分本質リスト) | An ingredient on this list cannot be manufactured or sold as a food in Japan at all, regardless of dose, form or claim |
| ”Non-medicinal unless claimed” ingredient list (医薬品的効能効果を標ぼうしない限り医薬品と判断しない成分本質リスト) | An ingredient on this list can be a food, provided the product does not carry a medicinal-style claim, dose or form that would tip it back toward medicine |
Both lists are attached to the current version of “食薬区分における成分本質（原材料）の取扱いの例示” (an illustrative list of how ingredient substances are treated under the food-medicine boundary), which MHLW amends from time to time — most recently through notices issued in 2020, 2021 and 2023 at the time of writing. A brand should always confirm an ingredient’s current listing rather than rely on its status from an earlier year.
How the judgement is made: ingredient, claim, dose and form together
MHLW does not judge an ingredient in isolation — it weighs the substance itself, the effect claimed for it, the dosage form, and the usage directions together, following the four factors set out in the 1971 notice.
| Factor | What it looks at |
|---|---|
| Ingredient itself (成分本質) | Whether the raw material is one that is, by its nature, used exclusively as a medicine — for example, a substance with strong pharmacological or toxic activity |
| Claimed effect (効能効果) | Whether the labelling states or implies that the product treats, prevents or cures disease, or enhances a bodily function beyond ordinary nutrition |
| Dosage form (剤型) | Whether the product takes a form Japan has traditionally associated with medicine, such as a tablet, pill, capsule or ampoule |
| Usage directions (用法用量) | Whether the label gives medicine-style dosing instructions, such as a fixed number of times per day tied to meals |
No single factor decides the outcome by itself; a food-permitted ingredient formed into a tablet with a disease-treatment claim and meal-timed dosing instructions can still be pushed toward medicine status by the combination, even if the raw ingredient itself sits on the non-medicinal list.
💬 Working with an ingredient you are not sure is food-permitted in Japan? Send us the ingredient name and we will check its current status before you commit to a formula.
Ingredients where the boundary matters most
The boundary most often surfaces with ingredients that are freely sold as supplements in other markets but sit close to, or on, Japan’s exclusively-medicinal list.
Sunsho maintains dedicated status guides for several ingredients where this question comes up often: melatonin, ashwagandha, taurine, glutathione and tranexamic acid. Each has its own current classification, and none of these should be assumed food-permitted or medicine-only just because of its status in another country.
What it means for an export OEM order
A Japanese factory manufactures under Japanese pharmaceutical law regardless of where the finished product will be sold, so an ingredient on the exclusively-medicinal list cannot be made there as a food even for an export-only order.
The food-medicine boundary is a manufacturing-jurisdiction rule, not a market-access rule: it governs what a factory operating in Japan is legally permitted to produce as a food, independent of the destination market’s own rules. That has two practical consequences for an OEM brief:
- An ingredient that is a legal supplement ingredient in your home market may still be unusable in a Japan-made product if it sits on Japan’s exclusively-medicinal list — the destination market’s rules do not override this.
- Conversely, once an ingredient, claim, dosage form and usage directions together clear the food side of the boundary, the resulting product can usually be exported, since the boundary itself is about domestic manufacturing status, not export eligibility.
This is also why a Japanese factory cannot obtain a Certificate of Free Sale for a product it could not legally manufacture as a food in Japan in the first place.
Before you ask for a quotation
Clearing every ingredient, claim, dosage form and usage direction against the current lists before formulation avoids a rejected specification later.
- Full ingredient list, including any companion or minor ingredients
- The health claim or positioning you intend to use on pack
- Your preferred dosage form and any usage directions you plan to print
- Whether any ingredient has a known or suspected borderline status in Japan
💬 Ready to check your full formula against Japan’s food-medicine boundary? Send us the ingredient list and intended claim before you finalise the specification.
Frequently asked questions
1. What is shoku-yaku kubun?
Japan’s system for deciding whether a raw material, and a product made from it, is legally a food or must be treated exclusively as a pharmaceutical, based on a 1971 government notice and two official ingredient lists that MHLW maintains and periodically revises.
2. Can an ingredient be food in one product and medicine in another?
Yes, for ingredients on the “non-medicinal unless claimed” list. The same substance can stay food-permitted with an ordinary food claim and form, or be pushed toward medicine status by a disease claim, a medicine-style dosage form, or medicine-style usage directions.
3. Does an ingredient’s legal status abroad affect its status in Japan?
No. Japan’s food-medicine boundary is decided independently by MHLW using its own lists and criteria; a supplement ingredient that is legal elsewhere is not automatically food-permitted in Japan.
4. If my product is only for export, does the boundary still apply?
Yes. A Japanese factory manufactures under Japanese pharmaceutical law regardless of the export destination, so an ingredient on the exclusively-medicinal list cannot be made there as a food even for an export-only order.
5. How often do the lists change?
MHLW revises the underlying lists periodically — several revisions have been issued in recent years — so a brand should confirm an ingredient’s current listing rather than rely on an earlier check.
Sources: Ministry of Health, Labour and Welfare, “無承認無許可医薬品の指導取締りについて” (Notice No. 476, 1 June 1971) (mhlw.go.jp/web/t_doc?dataId=00ta6938&dataType=1); Ministry of Health, Labour and Welfare, “食薬区分における成分本質（原材料）の取扱いの例示” and its amendment notices, including 令和2年3月31日付薬生監麻発第331009号, 令和3年11月1日付薬生監麻発第1101002号, and 令和5年2月17日付薬生監麻発第217001号 (mhlw.go.jp/web/t_doc, various dataId); Japan Health and Nutrition Food Association, commentary on food-medicine boundary revisions (jhnfa.org/topic145.html); National Institute of Biomedical Innovation, Health and Nutrition, “「健康食品」の安全性・有効性情報”, column on shoku-yaku kubun (hfnet.nibn.go.jp/column/detail4999/). Checked on 25 September 2026.