Origin & tradition
Yuan Zhi (远志, Polygala root) is a principal neuroprotective herb in Chinese medicine, categorized under calming-the-mind (安神) tonics that benefit the heart-mind connection and enhance memory.
Eastern tradition · Tonic Herbs
Polygala (Yuan Zhi) 远志
A classical TCM spirit-calming herb studied for BDNF induction, cholinesterase inhibition, and cognitive aging in East Asian trials.
↑ iHerb link is an affiliate link — we may earn a commission at no cost to you.
Why longevity buyers care
Key active: Tenuifolin & onjisaponins (root of Polygala tenuifolia).
Tenuifolin and onjisaponins stimulate BDNF production, activate TrkB signaling, and inhibit acetylcholinesterase. Multiple East Asian RCTs (Japan, Korea, China) report cognitive improvements in mild cognitive impairment and early dementia. Preclinical aging data covers autophagy and oxidative stress.
Effect summary
Studied health outcomes
Editorial summary — This table is curated by hand from published research consensus, not automatically calculated from our trial database. Grades reflect our interpretation of the literature. Treat as a starting point, not a definitive verdict. See the Evidence panel below for the underlying trial and paper counts sourced directly from ClinicalTrials.gov and PubMed.
| Health outcome | Effect | Magnitude | Grade |
|---|---|---|---|
| Cognitive function / memory | Increases | Moderate | C |
| BDNF (brain-derived neurotrophic factor) | Increases | Minor | C |
| Depression scores | Decreases | Minor | C |
| Neuroprotection markers — Mostly animal data | Increases | Minor | D |
Grade: A = robust RCTs · B = several RCTs / meta-analysis · C = limited or mixed RCTs · D = observational or early data
Dosage guidance
How Polygala (Yuan Zhi) is typically used
- Typical dose
- 300–600 mg/day extract
- Form
- capsule (Polygala tenuifolia root extract, standardized to onjisaponins)
- Timing
- morning or afternoon for cognitive effects
Yuan Zhi (远志) is a traditional Chinese nootropic used for over 2,000 years for memory and cognition. Contains onjisaponins, tenuigenin, and BNT-III. Research base is growing but mostly from East Asian institutions.
Informational only — not a prescription or personalised medical advice. Consult a qualified clinician before starting any supplement or medication.
Evidence summary
What the research actually says
68Evidence confidence
Early / limited human trials4 randomized controlled trials · 6 meta-analyses / systematic reviews
East Asian human RCTs on cognitive aging; mechanistic aging data preclinical
Tenuifolin and onjisaponins stimulate BDNF production, activate TrkB signaling, and inhibit acetylcholinesterase. Multiple East Asian RCTs (Japan, Korea, China) report cognitive improvements in mild cognitive impairment and early dementia. Preclinical aging data covers autophagy and oxidative stress.
13registered clinical trials reference this intervention
0selected peer-reviewed papers (longevity / aging angle)
Key active: Tenuifolin & onjisaponins (root of Polygala tenuifolia) — a multi-compound botanical extract, so activity is not reducible to a single molecule.
According to PubMed and ClinicalTrials.gov: trial counts from ClinicalTrials.gov, peer-reviewed literature from PubMed. Counts auto-refresh weekly; last checked 2026-06-12. They include trials across many endpoints, not only longevity.
Informational only — not medical advice, a treatment claim, or a substitute for a qualified clinician. Evidence strength varies; we show mixed and null results on purpose.
Evidence collections
Polygala (Yuan Zhi) appears in
Compare the evidence
Related ingredients
Reishi (Ganoderma lucidum)灵芝
72The classic Chinese longevity mushroom; emerging research connects its triterpenes to anti-aging and α-Klotho signalling.
Ginseng (Panax ginseng)人参
78The archetypal adaptogen; ginsenoside-rich extracts extend healthspan in model organisms via mitochondrial and stress pathways.
Schisandra五味子
69The “five-flavor berry,” an adaptogen studied for liver protection, stress resilience, and cellular defense.
Panax Notoginseng (Sanqi)三七 · 田七
76Yunnan's best-evidenced longevity herb — cardiovascular protection, anti-inflammation, and blood-flow support with 200+ registered clinical trials.
Suppliers