Bilberry (Vaccinium myrtillus) is a European berry, but most of the clinical research brands ask us about was run in Japan, on standardised extract taken by office workers who spend the day looking at screens. That combination — a familiar Western berry with Japanese clinical data — is why brands abroad request a Japan-made bilberry product.
This guide is for brand owners planning a bilberry product made in Japan. It covers what the human trials measured, how small and limited that evidence base still is, how Japanese Foods with Function Claims frame the ingredient, and what to fix before a quotation.
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 bilberry product made in Japan? We check the full formula against Japanese food law first. See Japan-made supplement OEM.
What the research shows
A handful of small, mostly Japanese randomised trials report that standardised bilberry extract eases screen-related eye fatigue and supports the eye’s focusing muscle, but the evidence base is limited and largely unreplicated outside these groups.
| Study | Design/What was analysed | Reported result |
|---|---|---|
| Randomised, double-blind, placebo-controlled trial, The Journal of Nutrition, Health & Aging 2015 (PMID 25923485) | Japanese office workers aged 20–40 using visual display terminals: 281 screened, 88 with relatively low eye-fatigue test values enrolled, 80 completed; bilberry extract 480 mg/day or placebo for 8 weeks | Bilberry extract improved some objective and subjective measures of eye fatigue versus placebo; other measures showed no difference |
| Randomised, double-blind, placebo-controlled, parallel-group trial, Nutrients 2020, 12(3):600 (DOI 10.3390/nu12030600, PMC7146147) | 109 healthy adults aged 20–60; standardised bilberry extract 240 mg/day or placebo for 12 weeks; objective ciliary-muscle (focusing) measures after visual load | Post-load focusing measures were significantly better in the bilberry group at weeks 8 and 12 versus placebo |
Caveats to keep in view:
- Size and setting. Both trials above are small (88 and 109 participants randomised), were run in Japan, and independent replication outside these teams is limited.
- Industry funding. Both trials were funded or conducted by bilberry ingredient manufacturers, and some authors of each were employees of those companies.
- Outcomes are largely functional/subjective. The measures are eye-fatigue symptom scores and objective focusing tests, not disease outcomes, and several sub-measures in these trials showed no significant difference from placebo.
Checked against the published abstracts on 13 October 2026.
What Japanese products say
In Japan, bilberry-derived anthocyanin appears in Foods with Function Claims notified for functions described as supporting the eye’s focusing ability and easing the feeling of eye fatigue, including fatigue and shoulder/neck discomfort linked to eye use.
Under Japan’s Foods with Function Claims system, the notifying business is responsible for the scientific evidence behind the stated function and submits it to the Consumer Affairs Agency before sale. Notified bilberry products commonly describe support for focusing (pinto chosetsu) and relief of the sensation of tired eyes — functional, everyday wording, not a claim about eye disease.
Two lessons for a brand abroad:
- The notified function is narrow and descriptive. It is about focusing support and the feeling of eye fatigue from screen use, not vision correction or disease prevention.
- A Japanese notification is a Japanese mechanism. It reflects the evidence a specific business submitted for its specific extract and dose, and does not transfer to your market’s rules or to a different bilberry material.
💬 Need an evidence summary for your regulatory adviser that is honest about how small this evidence base still is? We prepare it with the manufacturing documents. Tell us your market.
Wording that stays on safe ground
Describe bilberry by what was studied — screen-related eye fatigue and focusing — and keep the evidence’s small scale in view; never promise improved eyesight or protection from eye disease.
| Safer wording | Wording to avoid |
|---|---|
| ”Studied for eye fatigue after screen work" | "Improves eyesight”, “prevents eye disease" |
| "Contains standardised bilberry extract” with the anthocyanin content and amount per serving | ”Clinically proven” without naming the study, its size and its dose |
| ”Studied for focusing (accommodation) after visual tasks” | Comparisons to prescription eye treatments or corrective lenses |
How bilberry is formulated
Bilberry is supplied as a standardised dry extract measured by anthocyanin content, which fits easily into a hard capsule or tablet.
| Dosage form | Why brands choose it | What to weigh up |
|---|---|---|
| Hard capsule | Simple, flavourless, standard for a standardised dry extract | Fill weight versus the extract’s bulk density |
| Tablet | Low cost per serving, easy to combine with other eye ingredients | Extract colour can stain tablet coatings; needs testing |
| Powder stick | Possible for a combined “eye” blend | Strong colour and taste need masking |
Decisions that shape the specification:
- Standardisation. Ask the supplier for the extract’s anthocyanin content (commonly standardised to a stated percentage) and the amount that matches the dose used in the trial you plan to cite — 480 mg extract/day, 240 mg extract/day or a comparable anthocyanin amount, depending on the material.
- Source and authentication. Bilberry extract is a target for adulteration with cheaper, similarly coloured berries. Ask for a certificate of analysis that confirms species and anthocyanin profile, not colour alone.
- Companion ingredients. Lutein, zeaxanthin and astaxanthin are common eye-formula partners in Japan. Each needs its own check against Japanese food law and your market’s rules.
- Stability and packaging. Anthocyanins are sensitive to light, heat and moisture; ask the factory for stability data at your target shelf life and market climate.
The check that comes first
Every ingredient must be permitted in foods in Japan, or a Japanese factory cannot make the product.
Bilberry extract is widely used in Japanese foods. Combined “eye” formulas sometimes add botanicals that need their own review under Japanese food law before a factory can commit. See the Japan-made supplement OEM page, and our lutein and zeaxanthin and astaxanthin guides if you are planning a combined eye-health product.
Before you ask for a quotation
A factory can quote accurately once the extract standardisation, the amount, the form and the packaging are fixed.
- Bilberry extract standardisation (anthocyanin content) and amount per serving
- Source and authentication documentation
- Dosage form and any companion ingredients
- Packaging suited to light and moisture protection
- Countries you will sell in, and first order and annual volume
💬 Ready to design a Japan-made bilberry product? Send us the concept — extract standardisation, amount, form and the countries you will sell in.
Frequently asked questions
1. Does bilberry really help with eye strain from screens?
A small number of mostly Japanese randomised trials report improvements in eye-fatigue symptoms and objective focusing measures with standardised bilberry extract over 8–12 weeks. The trials are small and evidence is limited, so describe the ingredient as studied for screen-related eye fatigue, not as a proven cure for it.
2. How much bilberry extract do the studies use?
The trials above used 480 mg/day of extract for 8 weeks, or 240 mg/day for 12 weeks, depending on the material and its standardisation. Match your labelled amount to the study you cite.
3. Is bilberry the same as blueberry?
No. Bilberry is a related but distinct species, and the research described here used bilberry (Vaccinium myrtillus) extract specifically. Source and species authentication matter for a genuine ingredient.
4. What does Japan’s Foods with Function Claims system say about bilberry?
Notified bilberry products describe support for focusing ability and relief of the feeling of eye fatigue from screen use — an everyday functional claim, not a disease claim, and specific to the notifying business’s evidence.
5. What can stop a Japanese factory making my bilberry product?
Usually authentication issues with the raw extract, or a companion botanical in a combined eye formula. Every ingredient must be permitted in foods in Japan, so we check the full formula and the material’s certificate of analysis first.
Sources: “Bilberry extract supplementation for preventing eye fatigue in video display terminal workers”, The Journal of Nutrition, Health & Aging 2015, 19(5):548-554 (PMID 25923485, PMC12877697); “A 12-Week-Long Intake of Bilberry Extract (Vaccinium myrtillus L.) Improved Objective Findings of Ciliary Muscle Contraction of the Eye: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Comparison Trial”, Nutrients 2020, 12(3):600, DOI 10.3390/nu12030600 (PMID 32106548, PMC7146147); Consumer Affairs Agency notifications for Foods with Function Claims. Checked on 13 October 2026.