Bilberry
A systematic review of 12 placebo-controlled trials found the most rigorous night vision trials negative in people with normal eyesight. A 109-person trial reported less eye muscle tension after screen work. Pooled trials found no significant change in blood sugar, total cholesterol or blood pressure. In one trial, the adverse events reported were judged unrelated to bilberry.
- Status
- Dietary supplement in the US. Not FDA-approved for any condition.
- Also called
- Vaccinium myrtillus, European blueberry, whortleberry, bilberry extract, anthocyanosides, Mirtoselect
- Taken for
- eye health, night vision, eye strain, dry eye, blood sugar, cholesterol
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help2
Reported risks0
No risks sourced yet.
What people take it for, and what was found
Shown to help2
Eye strain from screens
Small trials found bilberry improved objective eye focusing measures after screen tasks. Symptoms were not measured.
The numbers and sources
- Effect
- After 12 weeks of 240 mg a day, a measure of ciliary muscle tension after display tasks (HFC-1) was better than placebo at weeks 8 and 12 (p 0.014 and 0.017) [2]. In myopic adults, 400 mg a day of a fermented extract for 1 month raised accommodation from 4.62 to 5.33 diopters (p 0.002) and mesopic contrast sensitivity, with no change on placebo [3].
- Population
- 109 healthy adults aged 20 to 60 [2]. 30 middle-aged adults with myopia [3].
- Sources
- [2], [3]
- Caveats
- Both measured eye focusing objectively, not symptoms. [3] reported changes within each group.
Dry eye
One very small trial found tear volume rose on bilberry over 4 weeks and not on placebo in 21 adults with dry eye.
The numbers and sources
Mixed results1
Night vision
Mixed results: the 4 most recent randomized trials found no night vision benefit, while less rigorous trials reported positive effects, mostly in people with normal eyesight.
The numbers and sources
- Effect
- Of 30 trials with outcomes relevant to vision in low light, 12 were placebo-controlled. The 4 most recent were randomized and negative. A fifth RCT and 7 non-randomized controlled trials reported positive effects. Negative results went with more rigorous methods, but also with lower doses and extracts from different sources [1].
- Population
- Healthy subjects with normal or above average eyesight in 11 of the 12 trials [1].
- Sources
- [1]
- Caveats
- No rigorous trial tested people with impaired night vision from eye disease [1].
Not shown to help1
Blood sugar and cholesterol
Not shown to change fasting glucose, cholesterol, blood pressure or weight in adults across 8 small trials.
The numbers and sources
- Effect
- Across 8 pooled trials, fasting glucose (-0.08 mmol/L, 95% CI -0.22 to 0.07), total cholesterol (-0.11 mmol/L, 95% CI -0.30 to 0.08), triglycerides, HDL, blood pressure and weight did not change significantly. HbA1c fell 1.63 points (95% CI -3.36 to 0.11, p 0.06) in 3 trials. LDL rose 0.07 mmol/L (95% CI 0.01 to 0.14) in long-term trials [5].
- Population
- 11 RCTs with 409 adults, 8 in the meta-analysis [5].
- Sources
- [5]
- Caveats
- Small trials. Triglycerides fell in crossover trials and trials of 4 weeks or less [5].
Doses studied
The screen trial used 240 mg of a standardized extract a day for 12 weeks [2]. The myopia trial used 400 mg of a fermented extract a day for 1 month [3]. The dry eye trial ran 4 weeks [4].
Risks
Checked, no increase found1
Adverse events
Small trials found no adverse events that doctors judged related to bilberry. Headaches were more frequent on extract in one trial, 18 of 55 against 11 of 54.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- In 109 adults given 240 mg a day or placebo for 12 weeks, the full text reports headaches in 18 of 55 on extract and 11 of 54 on placebo, colds in 10 and 12, and stomach ache or diarrhea in 6 and 6. Physicians judged all events unrelated to the extract, and blood and urine tests showed no related changes [2]. In 88 office workers given 480 mg a day or placebo for 8 weeks, there were no severe adverse events in either group [6].
- Population
- 109 healthy adults aged 20 to 60 in Japan [2]. 88 office workers aged 20 to 40 in Japan [6].
- Sources
- [2], [6]
- Caveats
- Two trials of 8 to 12 weeks, too small to detect rare harms. The headache difference was not tested statistically in the trial report [2]. The second abstract reports only severe events [6].
Claims tested and not found
Sources
- Canter PH, Ernst E. Anthocyanosides of Vaccinium myrtillus (bilberry) for night vision. A systematic review of placebo-controlled trials. Survey of Ophthalmology. 2004. https://doi.org/10.1016/j.survophthal.2003.10.006
- Kosehira M, Machida N, Kitaichi N. 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. https://doi.org/10.3390/nu12030600
- Kamiya K, Kobashi H, Fujiwara K, et al. Effect of fermented bilberry extracts on visual outcomes in eyes with myopia: a prospective, randomized, placebo-controlled study. Journal of Ocular Pharmacology and Therapeutics. 2013. https://doi.org/10.1089/jop.2012.0098
- Riva A, Togni S, Franceschi F, et al. The effect of a natural, standardized bilberry extract (Mirtoselect) in dry eye: a randomized, double blinded, placebo-controlled trial. European Review for Medical and Pharmacological Sciences. 2017. https://pubmed.ncbi.nlm.nih.gov/28617532/
- Talebi S, Shirani M, Mahdavi A, et al. Investigating the Effects of Vaccinium myrtillus Supplementation on Cardiometabolic Indices: A Systematic Review and Meta-Analysis. Phytotherapy Research. 2025. https://doi.org/10.1002/ptr.70054
- Ozawa Y, Kawashima M, Inoue S, et al. Bilberry extract supplementation for preventing eye fatigue in video display terminal workers. The Journal of Nutrition, Health & Aging. 2015. https://doi.org/10.1007/s12603-014-0573-6