Quick Navigation

Rubus coreanus

Rubus coreanus (Korean Black Raspberry) is a dark berry sometimes brewed as a wine called bokbunja ju; it has a high levels of anthocyanins of the cyanidin type, and other tannin structures that underlie its antioxidant and proerectile properties.

Our evidence-based analysis on rubus coreanus features 51 unique references to scientific papers.

Research analysis led by .
Reviewed by
Examine.com Team
Last Updated:

Summary of Rubus coreanus

Primary information, health benefits, side effects, usage, and other important details

Rubus coreanus (Korean black raspberry) is a berry from the raspberry family yet contains such a large content of anthocyanins that it is seen as nutritionally comparable to blueberry and related berries. When looking at Korean black raspberries though, they seem to carry bioactives from the raspberry family as well as the anthocyanins making them (in all practical terms) some manner of naturally occurring hybrid.

The berries are a commerical product in Korea for the most part (hence the name) and are used to make jams, jellies, food products, and most notably a wine called bokbunja ju. The unripe berries (not so much the ripe, since whatever main bioactive is in there seems to decline during the aging process) are a medicinal product for blood flow and circulation as well as male sexuality (aphrodisia and erectile function).

When looking at the berries, they are for the most part comparable to blueberries or aronia melanocarpa due to being a good source of anthocyanins. There are some unique properties of these berries though, and they seem to be related to calcium metabolism. Specifically, the berries reduce calcium release from the sarcoplasmic reticulum of cells when it would otherwise be stimulated (in a manner that can drop below baseline levels if high enough in concentration) and due to this the contraction seen in vessels including the penis that would normally occur from calcium release is attenuated.

A rat study has noted abnormally high increases in testosterone (700%) but such an increase has failed in the pilot study on healthy men. We cannot fully conclude that a testosterone boost cannot occur in men (since there were difference in the sources of the berry, stage of ripening, and dosage) but at this moment it does not look too promising.

Also tied into the testosterone would be an increase in spermatogenesis and sperm motility seen in male rats fed the unripe berries, which oddly seems to occur without changes in testicular size. This has not yet been tested in humans.

💊 Get unbiased supplement information

How to Take

Recommended dosage, active amounts, other details

The one human study on the subject matter used 30g of the freeze dried berries and noted antioxidative and liver benefits associated with that dose. For the food product it is probably a good starting point, and there is not enough information to assess if one can use bokbunja ju for health reasons.

Many other studies in rats use the supplemental doses of 100-500 mg/kg of the unripe berry powder. In human terms, this gives us estimates of (the following is dry weight of the berry):

  • 1,100-5,450 mg for a 150lb person

  • 1,450-7,300 mg for a 200lb person

  • 1,800-9,000 mg for a 250lb person

If using unripe berries with a water content, it will need to be recalculated.

Easily stay on top of nutrition research

Become an Examine.com member to get access to the latest research. 150+ studies summarized across 25 different categories every month.

Becoming a member also unlocks our study database of 400+ supplements and their effects on 600+ health outcomes.

Already a member? Click here to log in.

Make informed decisions about your health

Human Effect Matrix

Unlocked for Examine members

The Human Effect Matrix summarizes human studies to tell you what effects Rubus coreanus has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-d Minor - See study
There appears to be a mild increase in glutathione peroxidase with no significant influence on catalase nor SOD in otherwise healthy men.
grade-d Minor - See study
In otherwise healthy men with no apparent health problems, there is a mild decrease in lipid peroxidation associated with consumption of the berries (12% reduction in MDA)
grade-d Minor - See study
In otherwise healthy men with no health problems, the mild reduction in lipid peroxidation seen was associated with a mild reduction in circulating ALP levels (6%) although AST and GST were unaffected.
grade-d - - See study
No significant alterations in fasting blood glucose are noted with daily berry consumption in otherwise healthy persons.
grade-d - - See study
In otherwise healthy men, there are no changes in C-reactive protein levels seen with berry consumption.
grade-d - - See study
No significant influence of the berries on HDL cholesterol levels in men who are otherwise healthy.
grade-d - - See study
No significant influence of rubus coreanus on LDL cholesterol levels in otherwise healthy persons.
grade-d - - See study
Despite the highly promising evidence in rats, there is no significant influence of the berries on testosterone levels of otherwise healthy men.
grade-d - - See study
Currently the only study is in otherwise healthy men with no cholesterol problems, and there was no influence of berry consumption.
grade-d - - See study
No significant influence of this berry on the triglycerides of otherwise healthy men.

Stay on top of the latest research

Become an Examine Personalized member to access the latest nutrition research on over 400 supplements across more than 600 different health goals, outcomes, conditions, and more. Information tailored to you, updated every month.

Bonus: unlock the supplement Human Effect Matrix and all health topics on Examine.com.

Things to Note

Also Known As

Korean Black Raspberry, Rubus tokkura, Cha tian pao, bokbunja, Rubi Fructus

Do Not Confuse With

Rubus suavissimus (Chinese sweet leaf)

  • For medicinal usage, the unripe berries seem to be more relevant than the ripe berries

Get our free 5-day course on the essentials of supplementation.

At Examine.com, our incentives line up with yours — getting unbiased information. That's why we don’t sell any advertising or supplements.

Join over 250,000 people who have learned about effective versus overrated supplements, tips for buying supplements, and how to combine supplements for safety and efficacy.

Click here to see all 51 references.