Melatonin is sold as an over-the-counter sleep supplement in the United States and in parts of the European Union, so brands abroad sometimes assume a Japan-made melatonin product is simply a matter of finding the right factory. It isn’t. Japan treats melatonin as a substance used exclusively as a medicine, and that classification stops a Japanese factory from making it as a food, regardless of the dose or the market you plan to sell into.
This guide explains that status, what it means in practice, and which sleep-themed ingredients a Japanese factory can actually work with instead.
Health supplements are foods, not medicines, and are not a substitute for medical treatment. Nothing here is a claim that any product prevents, treats or cures a disease.
💬 Planning a sleep-themed product made in Japan? We check the full formula against Japanese food law first, before you commit to an ingredient. See Japan-made supplement OEM.
Melatonin’s status in Japan
Melatonin is listed among the substances Japan’s Ministry of Health, Labour and Welfare treats as used exclusively as medicines, so it cannot legally be sold as a food ingredient in Japan.
Japan’s food-drug classification system (食薬区分) maintains a list of ingredients treated exclusively as pharmaceutical components. Melatonin is on that list. In June 2023 a Ministry of Health, Labour and Welfare working group reviewing the list specifically considered whether to move melatonin to the non-medicinal side, and decided against it, citing melatonin’s existing use as a prescription medicine in Japan and the lack of new evidence to justify reclassification. Japan approved a prescription melatonin medicine (for sleep-onset difficulty associated with neurodevelopmental conditions in children) in 2020, which reinforces its position as a medicine rather than a food ingredient. Japanese authorities have also taken enforcement action against so-called health foods found to contain melatonin, treating them as unauthorised pharmaceutical products.
In practice, this means:
- A Japanese GMP factory cannot manufacture a melatonin tablet, capsule, gummy or drink as a food, at any dose, because the ingredient itself is classified as a medicine, not because of a labelling or claims problem.
- This is a Japan-specific rule tied to the ingredient, not to what the product is called. A “melatonin supplement” sold freely elsewhere is still a medicine under Japanese food-drug classification.
How this compares elsewhere
Melatonin’s status varies sharply by market, which is exactly why it needs checking market by market rather than assumed from one country’s rules.
| Market | Status |
|---|---|
| Japan | On the list of substances treated exclusively as medicines; not permitted as a food ingredient, prescription-only as a medicine |
| United States | Regulated by the FDA as a dietary supplement; sold over the counter with minimal pre-market gatekeeping |
| United Kingdom | A medicine only; available as a prescription-only medicine (for specific indications), not permitted for sale as a food supplement at retail |
| European Union | Varies by member state; regulated as a medicinal product in much of the EU, though some countries permit low-dose melatonin (commonly around 1 mg or less per serving) as a food supplement with an authorised health claim about reducing time to fall asleep |
Confirm the current rule in each market you plan to sell in directly with that market’s regulator before you commit to a melatonin product; this table describes general positions, not a guarantee for any specific formulation or dose.
💬 Building a sleep-themed range and unsure which ingredients a Japanese factory can actually use? Tell us your concept and we check it against Japanese food law before you commit.
What to use instead
Japan can manufacture several other ingredients that are studied in relation to sleep quality and are permitted as foods, without the regulatory block that melatonin carries.
Three ingredients commonly used in Japanese sleep-themed products are permitted as foods and have their own study evidence, each covered in its own guide with honest treatment of what the evidence does and does not show:
- GABA — appears in Japanese Foods with Function Claims for functions including supporting sleep quality, though independent systematic review evidence is limited.
- L-theanine — an amino acid from tea, studied in relation to relaxation and sleep quality.
- Glycine — an amino acid studied in relation to subjective sleep quality.
None of these ingredients works the same way as melatonin, and none should be marketed as a melatonin substitute or equivalent — that would overstate the evidence and misrepresent how each ingredient is actually studied. Each has its own dose, evidence base and formulation considerations, covered in its own guide.
The check that comes first
Every ingredient must be permitted in foods in Japan, or a Japanese factory cannot make the product — melatonin fails this check outright, which is why this guide exists before you commit to a concept.
This is the same check that applies to every ingredient on this site, and melatonin is one of the clearest examples of an ingredient that fails it completely rather than needing a formulation adjustment. See the Japan-made supplement OEM page for how we check a full formula before quoting.
Before you ask about a sleep-themed product
Tell us the sleep-related benefit you want to build around, and we confirm which ingredients a Japanese factory can actually use before any formulation work begins.
- The sleep-related outcome you want the product associated with
- Any ingredients you already have in mind, so we can check their Japanese status first
- Dosage form preference
- Countries you will sell in, and each market’s rules on sleep-supplement ingredients and claims
- First order and annual volume
💬 Have a sleep-themed concept in mind? Send it to us and we will tell you plainly which ingredients Japan can make, before any formulation work begins.
Frequently asked questions
1. Can a Japanese factory make a melatonin supplement at a low dose, like 1 mg?
No. Melatonin’s status as a substance treated exclusively as a medicine in Japan applies to the ingredient itself, not to a specific dose. Even a 1 mg product cannot legally be manufactured as a food in Japan.
2. Is this likely to change soon?
A 2023 Ministry of Health, Labour and Welfare working group specifically reviewed whether to reclassify melatonin and decided to keep it on the medicines-only list, citing its existing prescription-medicine use in Japan. There is no indication of an imminent change.
3. Can I import a melatonin product made elsewhere and sell it through a Japanese company?
That is a different question from manufacturing, and depends on import and market-entry rules rather than this guide’s scope of Japanese food manufacturing. What this guide confirms is that a Japanese factory cannot manufacture the product as a food.
4. Are GABA, theanine and glycine equivalent to melatonin?
No. Each works differently and has its own separate evidence base, generally more limited and less direct than melatonin’s sleep-onset evidence as a medicine. They are alternatives that Japan can legally manufacture as foods, not substitutes with matching effects.
5. Why do other countries allow melatonin as a supplement if Japan does not?
Countries classify substances differently based on their own regulatory history and risk assessments. The United States treats melatonin as a dietary supplement; the United Kingdom treats it as a prescription medicine; within the European Union its status varies by country and by amount. Japan treats it as a medicine, and has an approved prescription melatonin medicine on its market, which reinforces that classification.
Sources: Japan 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 (list of substances treated exclusively as medicines, includes melatonin); Ministry of Health, Labour and Welfare 食薬区分ワーキンググループ meeting summary, 26 June 2023, on the review of melatonin’s classification (published 27 July 2023); Ministry of Health, Labour and Welfare enforcement notice on unauthorised health foods found to contain the pharmaceutical ingredient melatonin (mhlw.go.jp/kinkyu/diet/other/080611-1.html); e-ヘルスネット (MHLW), melatonin entry, noting no Japanese manufacturing/marketing approval for melatonin outside the prescription medicine route. Checked on 25 September 2026.