Every tablet, capsule or stick pack has ingredients beyond the ones printed on the front of the pack. Fillers bulk out a small dose to a workable size, binders and disintegrants hold a tablet together and then let it fall apart in use, and lubricants and glidants keep the powder moving through the machine. None of these is optional once you choose a dosage form — the question is which one, in what amount, and how it is written on the label.
This guide covers the excipient families used in Japan-made supplements, how Japanese food law treats and labels them, the “clean label” trade-offs brands run into when they ask for fewer additives, and what to fix before a factory can quote.
💬 Choosing excipients for a Japan-made supplement? We check the full formula against Japanese food law before it goes to specification. See Japan-made supplement OEM.
What each excipient family does
Fillers add bulk, binders and disintegrants control how a tablet holds together and breaks apart, and lubricants and glidants keep powder flowing through the machine — a formula normally needs at least one from each group it uses.
| Family | What it is | Why it is needed | Watch-outs |
|---|---|---|---|
| Fillers (bulking agents) | Cellulose, dextrin, lactose and similar bulk materials | A small dose of active ingredient (a few milligrams) is too little to compress or fill on its own | Lactose is milk-derived and is one of Japan’s mandatory allergen-labelling items; dextrin and cellulose sources vary in fibre content |
| Binders | Substances that hold powder particles together during compression or granulation | Without a binder, a tablet crumbles or a capsule fill does not hold shape | Too much binder slows disintegration |
| Disintegrants | Substances that make a tablet break apart in liquid | Lets the active ingredient release after swallowing, rather than passing through intact | Under-use leaves a hard, slow-dissolving tablet; interacts with the choice of binder |
| Lubricants | Magnesium stearate, calcium stearate, sucrose fatty acid esters | Reduces friction between powder and the tablet press or capsule machine, so the equipment does not jam or stick | Used at very low levels; too much can slow disintegration |
| Glidants | Silicon dioxide (synthetic silica) | Improves powder flow into the die or capsule, giving a more even fill weight | Also used at low levels; not a substitute for a genuine lubricant |
Not every dosage form needs every family. A gummy or a jelly stick uses gelling and thickening agents instead (covered in our dosage-form guides); tablets and capsules are where fillers, binders, disintegrants, lubricants and glidants matter most.
How Japan classifies and labels these substances
Japan sorts every food additive, including excipients, into one of four legal categories, and most tableting aids are labelled by their plain substance name rather than a functional category.
Japan’s Food Sanitation Act splits food additives into four groups: designated additives (approved individually by the health ministry), existing food additives (natural substances with a long history of use, grandfathered when the category was created in 1995), natural flavourings, and general food additives (ordinary foods, such as strawberry juice, also used as additives). Magnesium stearate and silicon dioxide are designated additives; cellulose derivatives and several natural bulking agents sit on the existing food additives list.
Japan’s Food Labelling Standards require most additives to appear in the ingredient list by their specific substance name. Only additives used as one of eight functions — sweeteners, colourants, preservatives, thickener/stabiliser/gelling agents, antioxidants, colour fixatives, bleaching agents and fungicides — must also carry a use-category word in front of the name (for example, “thickener (xanthan gum)”). Fillers, binders, disintegrants, lubricants and glidants are not on that list of eight, so they normally appear by substance name alone, such as “cellulose” or “silicon dioxide”, with no functional label attached.
Lactose is the exception that needs separate handling. Milk is one of Japan’s mandatory allergen-labelling items (alongside egg, wheat, buckwheat, peanut, shrimp, crab and walnut, with cashew nut added to the mandatory list in 2026), so any lactose-based filler triggers a milk-allergen declaration next to the ingredient, regardless of which food-additive category it sits in.
What “clean label” costs you
Cutting the excipient count usually means giving up something — machine speed, tablet hardness, shelf stability or cost — so a “clean label” request needs to say which trade-off the brand accepts.
“Clean label” pressure from some markets pushes brands to ask for fewer additives, or for ones with a more familiar name. That is achievable, but it moves the difficulty somewhere else in the process.
| Conventional choice | Common “clean label” alternative | What you gain | What you give up |
|---|---|---|---|
| Magnesium stearate (lubricant) | Sucrose fatty acid esters, or a rice-derived lubricant | A less synthetic-sounding name on the label | Different flow behaviour; the factory may need to re-trial the tablet press settings |
| Synthetic silicon dioxide (glidant) | Reducing or removing the glidant, relying on particle-size control instead | One fewer additive name on the label | Less consistent fill weight, more sensitive to humidity |
| Lactose filler | Cellulose or dextrin filler | Avoids the milk-allergen declaration | Different compressibility; dextrin sourced from starch may carry its own labelling considerations depending on source grain |
| Multiple single-function additives | A smaller number of multi-function excipients | Shorter ingredient list | Less room to fine-tune each property independently |
None of these substitutions is free. The honest approach is to tell the factory which trade-off matters most — machine reliability, label length, or avoiding one specific allergen — and let the formulation team choose the excipient set that satisfies that priority first.
💬 Deciding between a shorter label and a more robust production run? Send us the constraint that matters most and we will propose the excipient set that fits it. Tell us your priority.
How major export markets differ
The excipients themselves are widely accepted internationally, but how they are labelled — and whether they are labelled at all — differs by market.
In the EU, a substance used only as a processing aid, with no technological function left in the finished product, does not need to be declared as an additive; but a carrier or additive that originates from one of the EU’s listed allergens (which includes milk) must still be declared even when it serves no function in the final food. In the US, dietary supplement labels list excipients by name in an “Other ingredients” line under 21 CFR 101.4, but — unlike the active ingredients in the Supplement Facts panel — their quantities do not have to be disclosed. Japan, by contrast, expects the substance name for essentially every added excipient in the ingredient list, with no general processing-aid exemption for tableting aids.
The practical effect: a lubricant or filler that needs no declaration in one market can still require a named entry in Japan, and the reverse rarely happens. A specification written only against your home market’s label rules will usually need adjusting for the Japan-made version.
What to put in the specification
A factory can quote accurately once the filler, binder, disintegrant, lubricant and glidant are each named, along with the countries the finished product will be sold into.
- Dosage form. Tablet, hard capsule or stick — the excipient set differs by form.
- Active ingredient dose and particle behaviour. A very small dose needs more filler; a poorly flowing powder needs more glidant.
- Allergen tolerance. State whether a milk-derived filler (lactose) is acceptable, or whether it must be avoided.
- Label-length priority. Say whether a shorter ingredient list matters more than manufacturing tolerance, so the factory can propose accordingly.
- Markets of sale. Japan, the EU, the US and other destinations each have their own labelling treatment for the same excipient.
Before you ask for a quotation
- Dosage form and target tablet or capsule size
- Whether a milk-derived filler (lactose) is acceptable
- Any “clean label” priority, and which trade-off you will accept for it
- Countries you will sell in, and their excipient labelling rules
- Any other ingredients in the same formula that already carry allergens or additives of their own
💬 Ready to fix the excipient set for your Japan-made product? Send us the formula concept — active ingredient, dose, dosage form and the countries you will sell in.
Frequently asked questions
1. Are fillers and lubricants safe to use in supplements?
The ones commonly used in Japan-made supplements — cellulose, dextrin, magnesium or calcium stearate, sucrose fatty acid esters, silicon dioxide — are all permitted food additives in Japan, used at low levels for a specific mechanical function, not as active ingredients.
2. Why does lactose need special handling on the label?
Milk is one of Japan’s mandatory allergen-labelling items. A lactose-based filler is milk-derived, so it triggers a milk-allergen declaration on the pack regardless of how small the amount is.
3. Do fillers and lubricants need a “thickener” or “sweetener” style label in Japan?
No. Only additives used for one of eight specific functions — sweeteners, colourants, preservatives, thickener/stabiliser/gelling agents, antioxidants, colour fixatives, bleaching agents and fungicides — must carry a use-category word. Fillers, binders, disintegrants, lubricants and glidants are labelled by substance name alone.
4. Can I remove all excipients for a “clean label” product?
Not entirely, for a tablet or capsule — some filler, binder and lubricant is needed for the machine to run and the tablet to hold together. You can reduce the count or choose different substances, but each swap has a trade-off in manufacturability or shelf stability.
5. Do EU or US rules require the same label declarations as Japan?
Not always. The EU exempts some processing aids with no function left in the finished food (though allergen-derived ones like milk must still be declared), and the US lists excipients by name without quantities. Japan generally expects the substance name for every added excipient, so a formula built for one market’s label often needs adjusting for the others.
Sources: Food Sanitation Act food additive categories, Consumer Affairs Agency, Food Additives | CAA; Japan Food Chemical Research Foundation, List of Designated Food Additives (ffcr.or.jp); Consumer Affairs Agency, food additive labelling rules including the eight use-category functions (caa.go.jp); Consumer Affairs Agency, mandatory and recommended allergen labelling items, including the 2026 cashew nut addition; Regulation (EC) No 1333/2008 on food additives (carriers, processing aids and allergen-origin additives), eur-lex.europa.eu; US Code of Federal Regulations 21 CFR 101.4, dietary supplement “other ingredients” labelling. Checked on 25 September 2026.