A shelf-life date on a supplement label is a promise, and Japan’s rules distinguish between two different kinds of promise. Getting the wrong one — or setting a date that does not hold up once the product sits in a humid warehouse for a year — creates a returns problem long after the factory has shipped the order.
This guide explains Japan’s two date-labelling categories, how stability testing supports the date you choose, and why a shelf life set for Japan’s climate does not automatically transfer to a tropical export market.
💬 Setting a shelf life for a Japan-made product going to a hot, humid market? We build the stability plan into the formulation review. See Japan-made supplement OEM.
Best-before versus use-by
Japan’s Food Labeling Standard defines two separate date categories, and most supplements use the best-before category rather than the use-by category.
| Term | Japanese term | Official definition | Typical use |
|---|---|---|---|
| Use-by date | 消費期限 (shōhi kigen) | The date by which the food should be consumed, after which safety can no longer be assured due to spoilage or other quality deterioration, when stored as instructed | Foods that deteriorate quickly: fresh prepared foods, some chilled items |
| Best-before date | 賞味期限 (shōmi kigen) | The date up to which all the expected quality of the food can be fully maintained, when stored as instructed | Foods with a longer shelf life: most supplements, tablets, capsules, powders |
The Consumer Affairs Agency’s Food Labeling Standard sets these definitions, and the choice between them is based on how the product deteriorates, not on brand preference. A well-formulated tablet or capsule product, stored correctly, is expected to remain within its full quality specification for months or years, which is why the best-before category applies. A use-by date implies the product becomes unsafe, not merely lower quality, after the date — a distinction worth keeping in mind if a Japanese factory asks which category your product should use.
Stability testing concepts
Real-time stability testing under normal storage conditions gives the most reliable shelf-life data, and accelerated testing under stressed conditions estimates it faster while the real-time study continues.
- Real-time (long-term) stability testing. The product is stored at conditions representative of the destination market and tested at intervals (for example, 0, 3, 6, 12, 18, 24 months) for potency, appearance, moisture and microbial quality until it falls outside specification. This gives the most trustworthy shelf-life figure but takes as long as the shelf life itself.
- Accelerated stability testing. The product is stored at a higher temperature and humidity for a shorter period to estimate degradation faster, then used to set a provisional shelf life while the real-time study is still running. Accelerated data alone should not be the sole basis for a final, long shelf-life claim without real-time confirmation.
- ICH climatic zones. The International Council for Harmonisation defines climatic zones used to set standard stability-testing storage conditions by region. Zone II (temperate, including much of Japan) is commonly tested at 25°C/60% relative humidity; Zone IVb, the hot and very humid zone that includes most of Southeast Asia, is commonly tested at 30°C/75% relative humidity. A product stability-tested only to Zone II conditions has not been shown to hold its claimed shelf life in a Zone IVb market.
Setting shelf life for a tropical export market
A shelf life validated under Japan’s climate conditions does not automatically apply to a hot, humid destination market, and should be confirmed or re-tested against that market’s conditions.
Vietnam and most of Southeast Asia fall within ICH Zone IVb, where heat and humidity accelerate moisture uptake, oxidation and, for softgels, shell softening far faster than in Japan’s temperate climate. A shelf life set from stability data generated only under Zone II storage conditions is optimistic for a Zone IVb market, particularly for moisture-sensitive powders, probiotics and softgel shells.
Two practical responses for an export-focused product: request that the factory’s stability programme include Zone IVb (30°C/75% RH) conditions, or set a shorter, defensible shelf-life date for tropical markets even where Japan’s own stability data would support a longer one for the domestic market. Packaging choices — barrier bottle material, blister versus bottle, desiccants and oxygen absorbers — also do more work in a Zone IVb market than in Japan, so the shelf-life decision and the packaging decision should be made together rather than separately.
💬 Need a shelf-life figure that holds up in a hot, humid export market? Tell us the dosage form and destination markets.
Before you ask for a quotation
- Dosage form and any moisture- or oxidation-sensitive actives
- Destination markets, and whether they fall in a hot/humid climatic zone
- Whether you need best-before or use-by labelling (usually best-before for supplements)
- Requested shelf life (for example, 24 or 36 months) and whether it should be validated for tropical storage
- Packaging format, since bottle, blister and desiccant choices affect achievable shelf life
- Whether accelerated stability data alone is acceptable or real-time confirmation is required
💬 Ready to set a shelf life and stability plan for a Japan-made product? Send us the formula and destination markets.
Frequently asked questions
1. Do all supplements made in Japan use a best-before date rather than a use-by date?
Most do, because tablets, capsules and powders are formulated to hold their quality for an extended period. A use-by date applies to foods where safety, not just quality, is at risk after the date, which is uncommon for a properly formulated supplement.
2. Is accelerated stability testing enough to set a final shelf-life claim?
It is useful for an early, provisional estimate, but a defensible long-term shelf-life claim is best supported by real-time stability data collected under representative storage conditions, not accelerated data alone.
3. What is an ICH climatic zone and why does it matter for my product?
It is a standard classification of regional temperature and humidity conditions used to set stability-testing storage conditions. It matters because a product tested only under Japan’s Zone II conditions has not been shown to perform the same way in a hot, humid Zone IVb market like most of Southeast Asia.
4. Should I request Zone IVb stability testing even if my product is also sold in Japan?
If any meaningful part of your sales will go to a hot, humid market, yes — it gives you a shelf-life figure and packaging spec that hold up in the market that will stress the product hardest, rather than only the market Japan’s domestic data covers.
5. Can packaging make up for a marginal stability result?
Sometimes. A better barrier bottle, a blister format, or a desiccant/oxygen absorber can extend real-world shelf life for moisture- or oxygen-sensitive products, but packaging should be chosen alongside the stability data, not as a substitute for testing under representative conditions.
Sources: Consumer Affairs Agency, official definitions of 消費期限 and 賞味期限 under the Food Labeling Standard, caa.go.jp; ICH climatic zone classification and Zone IVb (30°C/75% RH) storage conditions as adopted for ASEAN-region stability guidance. Checked on 25 September 2026.