Summary of Polygala tenuifolia
Primary Information, Benefits, Effects, and Important Facts
Polygala tenuifolia, also known as Yuan Zhi, is a root used in Traditional Chinese Medicine.
It has traditionally been used for its protective effects on the brain.
Preliminary animal evidence suggests that Polygala tenuifolia has an antidepressant effect in rats. Polygala tenuifolia_ may improve cognition, but more research is needed to confirm this effect.
Rodent research suggests that Polygala tenuifolia is similar in mechanism and effectiveness to ketamine, which interacts with N-methyl-D-aspartic acid and its receptors. Rodent studies assessing Polygala tenuifolia’s anti-amnesiac and adaptogen-like properties suggest that the herb can increase the level of compounds responsible for brain growth, like nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF).
Though Polygala tenuifolia supplementation may slightly increase cognitive ability in elderly people, it has limited effect on healthy adults. Supplementing Polygala tenuifolia can improve spatial organization and recognition, but it does not improve short- or long-term memory formation, as measured by free or cued recall. Much more research is needed to determine if Polygala tenuifolia qualifies as a nootropic.
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How to TakeMedical Disclaimer
Recommended dosage, active amounts, other details
The only human studies on Polygala tenuifolia have used 100mg of an ethanolic extract called BT-11, three times a day, for a total daily dose of 300mg.
A traditional Chinese medicine remedy suggests taking 3-9 g (dry weight) of Polygala tenuifolia root through a water decoction, like tea or soup, to reduce forgetfulness.
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Human Effect Matrix
The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects polygala tenuifolia has on your body, and how strong these effects are.
|Grade||Level of Evidence [show legend]|
|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.
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.
|Minor||Moderate See 2 studies|
|Minor||- See study|
|Minor||- See study|
|-||Very High See 2 studies|
|-||- See study|
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Things to Note
Traditional Chinese medicine tends to use the root (dry weight) in a varying dose of 3-9 grams each day, consumed either straight or usually via some manner of hot water extraction (such as soup or tea)
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