Bilberry (Vaccinium myrtillus): Uses, Evidence and Safety
Bilberry (Vaccinium myrtillus): what reviews found for night vision, eye strain and blood sugar, what EU regulators accept for the fruit, and what safety information we could not find.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
What is Bilberry good for?
What the body uses it for, and how strong the evidence is. A normal job in the body is not proof that extra supplements add benefit; each card says which.
Eye strain from screen work
Preliminary or mixedIn one 12-week trial in 109 healthy adults, a standardised bilberry extract improved a measurement of tension in the eye's focusing muscle after screen tasks, compared with placebo.
Supplements: Promising but limited: one trial, one extract; symptoms were not the main outcome.
Night vision in healthy people
Not enough evidenceA systematic review found the idea that bilberry improves normal night vision is not supported by rigorous trials; the four most recent randomised trials were negative.
Supplements: No good evidence of benefit in healthy people with normal eyesight. The review found no rigorous research in people with impaired night vision.
Blood sugar (HbA1c)
Preliminary or mixedA 2025 meta-analysis of randomised trials found a borderline reduction in HbA1c and no significant change in fasting glucose.
Supplements: Preliminary: the HbA1c result was only marginally significant (p=0.06) in the abstract we read.
Blood fats, blood pressure and inflammation markers
Preliminary or mixedThe same meta-analysis found no clear effect on cholesterol, blood pressure, body weight or inflammation markers. Triglycerides changed only in short or crossover trials.
Supplements: No reliable benefit shown for these measures.
Antioxidant and anti-inflammatory activity
Lab or animal research onlyBilberry fruit is a rich natural source of anthocyanins, pigments believed to account for its antioxidant and anti-inflammatory effects seen in laboratory and other research.
Supplements: Not shown to benefit health in people from these findings.
Leg heaviness from minor circulation problems (traditional use)
Not enough evidenceThe EU herbal committee accepts fresh bilberry fruit for traditional use to relieve leg discomfort and heaviness linked to minor circulatory problems, in adults, for up to four weeks.
Supplements: Traditional-use status, not proof of effect.
Mild diarrhoea and minor mouth inflammation (traditional use)
Not enough evidenceThe EU herbal committee accepts dried bilberry fruit for traditional use in mild diarrhoea and minor inflammation of the lining of the mouth, in adults and children over 12.
Supplements: Traditional-use status, not proof of effect.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (1)
- Blood Sugar BalancePreliminary or mixed
A 2025 meta-analysis found a borderline fall in HbA1c but no clear change in fasting glucose. More long-term trials are needed.
Body systems (1)
- Blood Sugar SupportPreliminary or mixed
Trials give a borderline HbA1c reduction; evidence is early. People on diabetes medicines should ask first.
Body parts (1)
- EyesPreliminary or mixed
One trial improved a focusing-muscle measure in screen users. Rigorous reviews do not support better night vision in healthy people.
Functional actions (3)
- Anti-InflammatoryLab or animal research only
Anti-inflammatory effects have been reported in laboratory research; human benefit is unproven.
- AntioxidantLab or animal research only
Bilberry is rich in anthocyanins with antioxidant activity in laboratory research; this is not proof of benefit in people.
- Blood Sugar RegulationPreliminary or mixed
Borderline HbA1c reduction in pooled trials; fasting glucose unchanged.
Root causes (2)
- Medication Side EffectsDocumented risk
Bilberry has been reported to lower blood glucose, so it may add to the effect of diabetes medicines. Ask a pharmacist.
- Blood Sugar ImbalancePreliminary or mixed
Early trial evidence of a small HbA1c effect; not a substitute for diabetes care.
Biomarkers (1)
- HbA1cPreliminary or mixed
Pooled trials showed a borderline lower HbA1c (p=0.06 in the abstract).
Documented risks and interactions (2)
- Possible blood-sugar lowering with diabetes medicines. Bilberry has been reported to lower blood glucose, so people who take diabetes medicines should ask a pharmacist or doctor first.
- Safety information that is missing. The EU summaries report no side effects at the time of assessment and limit use to adults (fresh fruit, up to four weeks) or adults and children over 12 (dried fruit). The sources read did not address interactions with blood thinners, pregnancy, or breastfeeding.
Know the limits. Bilberry is mostly promoted for eyesight, but a systematic review of placebo-controlled trials found the idea that bilberry improves normal night vision is not supported by rigorous clinical studies. [1] The sources we read did not describe bilberry medicine interactions, bleeding risk or pregnancy safety. Not described is not the same as safe. One chapter reports that bilberry has been reported to lower blood glucose, so people on diabetes medicines should ask a pharmacist first. [2]
What it is
Bilberry is Vaccinium myrtillus L., family Ericaceae, an accepted name in the GBIF plant database. [3] The part used is the fruit, and it is one of the richest natural sources of anthocyanins, the pigments that give it a blue-black color. [2] This page is about bilberry. Blueberries eaten as a food are covered separately in Blueberries: What Research Shows. A study of a bilberry extract says little about a handful of blueberries, and the reverse is also true.Traditional use (not proof)
The European Medicines Agency's herbal committee (HMPC, summaries published 2015) accepts two traditional uses. It said these medicines have been used safely for at least 30 years, including at least 15 years within the EU. [4] Fresh bilberry fruit may be used to relieve discomfort and heaviness of legs related to minor blood circulatory problems. [4] Dried bilberry fruit may be used for mild diarrhoea and minor inflammation of the lining of the mouth. [5] The HMPC said there was insufficient clinical trial evidence for the fresh fruit, calling the effect plausible, and noted the lack of clinical studies for the dried fruit. [4][5] Traditional-use status is not proof that the medicine works.What research shows (research, not tradition)
| Use | What the source found | Evidence label | Population and form studied |
|---|---|---|---|
| Night vision | A review found 30 trials with relevant outcomes, 12 placebo-controlled. The 4 most recent randomized trials were negative. [1] | No good evidence of benefit (healthy people) | Mostly healthy adults; anthocyanoside extract |
| Impaired night vision from eye disease | The same review noted a complete absence of rigorous research in people with impaired night vision. [1] | Proper evidence not found | None |
| Eye strain from screen work | In 109 healthy adults, 240 mg a day of a standardized extract for 12 weeks improved a measure of ciliary muscle (focusing muscle) tension compared with placebo. [6] | Promising but limited; objective measure, not symptoms | Healthy adults; one extract. Two authors were employees of the company behind the extract. |
| Blood sugar, cholesterol, blood pressure | A 2025 meta-analysis of 11 randomized trials (409 people) found bilberry may help HbA1c and triglycerides but not other cardiometabolic measures, and called for long-term, high-quality trials. [7] | Promising but limited | Adults; various bilberry supplements |
The night-vision story. A popular story says bilberry jam sharpened pilots' eyesight in wartime. We did not read a source that documents this, so we do not repeat it as fact. The trial evidence we did read is in the table above.
For eyes more broadly, see Vitamins and Eye Health. Blood sugar topics are covered in Herbs for Blood Sugar and Diabetes.
Forms and why the form matters
Trials used standardized extracts of the fruit. [6][1] The EU summaries cover fresh fruit preparations and dried fruit taken as a tea or used as a mouth rinse. [4][5] Night vision results differed with dose and with the source of the extract, which the reviewers said may differ in composition. [1] A food, a tea and a capsule are not interchangeable. See Herb Forms and Preparations.Safety and who should ask first
- EU regulator: at the time of assessment, no side effects had been reported for the fresh fruit medicines or the dried fruit medicines. [4][5] That reflects what was reported then, not a guarantee.
- Age and duration: the EU summaries say fresh fruit should be used only in adults and not for longer than 4 weeks, and dried fruit only in adults and children over 12. [4][5] A doctor should be consulted if symptoms persist.
- Diabetes medicines: because bilberry has been reported to lower blood glucose, ask a pharmacist. [2] See Herbs and Diabetes, Blood Pressure and Heart Medicines.
- Blood thinners and surgery: the sources we read did not address this. Tell the surgical team and pharmacist. See Herbs and Blood Thinners and Supplements Before Surgery.
- Pregnancy, breastfeeding, liver, kidney, allergy: not described in the sources we read. See Pregnancy and Breastfeeding.
- Quality: extract strength and anthocyanin content differ by product. See Quality Testing and Certifications.
Official statements
- EMA, HMPC (2015): traditional use for leg heaviness (fresh fruit), and for mild diarrhoea and minor mouth inflammation (dried fruit). [4][5]
Frequently asked questions
Does bilberry improve night vision?
A systematic review found this is not supported by rigorous studies in healthy people. [1]
Is bilberry the same as blueberry?
Not in the studies we read. This page covers Vaccinium myrtillus, and a result for one extract does not transfer to another fruit or product. See the blueberry page for the food.
Does bilberry help eye strain?
One 12-week trial in 109 healthy adults improved a measure of focusing muscle tension. The authors included company employees, and symptoms were not the main result. [6]
Can bilberry lower blood sugar?
It has been reported to, and a 2025 meta-analysis saw a marginal HbA1c effect. [2][7] Ask a pharmacist if you use diabetes medicines.
What do EU regulators say about bilberry?
The HMPC accepts traditional use of the fresh fruit for leg heaviness and of the dried fruit for mild diarrhoea and mouth irritation. [4][5]
References
- Canter PH, Ernst E. Anthocyanosides of Vaccinium myrtillus (bilberry) for night vision: a systematic review of placebo-controlled trials. Survey of Ophthalmology, 2004. Read 2026-10-23.
- Chu WK, Cheung SCM, Lau RAW, Benzie IFF. Bilberry (Vaccinium myrtillus L.). In: Herbal Medicine: Biomolecular and Clinical Aspects, 2nd edition, 2011. Read 2026-10-23.
- GBIF Secretariat. Vaccinium myrtillus L., species match. GBIF Backbone Taxonomy. Read 2026-10-23.
- European Medicines Agency, HMPC. Myrtilli fructus recens (fresh bilberry fruit): summary for the public. Published 2015. Read 2026-10-23.
- European Medicines Agency, HMPC. Myrtilli fructus siccus (dried bilberry fruit): summary for the public. Published 2015. Read 2026-10-23.
- Kosehira M, Machida N, Kitaichi N. A 12-week-long intake of bilberry extract improved objective findings of ciliary muscle contraction of the eye: a randomized, double-blind, placebo-controlled trial. Nutrients, 2020. Read 2026-10-23.
- Talebi S, et al. Investigating the effects of Vaccinium myrtillus supplementation on cardiometabolic indices: a systematic review and meta-analysis. Phytotherapy Research, 2025. Read 2026-10-23.