Quick Comparison
| Gotu Kola | Polygala Tenuifolia | |
|---|---|---|
| Half-Life | 2-4 hours (asiaticoside, madecassoside) | 3-6 hours (tenuigenin and polygalasaponins) |
| Typical Dosage | Standard: 500-1000 mg standardized extract daily (triterpenes: asiaticoside, madecassoside). Traditional dose: 1-2 grams dried herb as tea. ECa 233 is a well-studied standardized extract. Can be taken morning or evening — mild enough for bedtime use. | Standard: 100-300 mg extract daily (standardized to 3,6'-disinapoyl sucrose or polygalasaponins). Can be taken morning or evening. Some users take it before bed for dream enhancement. Effects noticeable within hours of first dose. |
| Administration | Oral (capsules, extract, tea, tincture). ECa 233 standardized extract for consistent dosing. | Oral (capsules, powder, tincture). Extract preferred over raw root for potency and reduced GI irritation. |
| Research Papers | 9 papers | 10 papers |
| Categories |
Mechanism of Action
Gotu Kola
Triterpene saponins (asiaticoside, madecassoside, asiatic acid, madecassic acid) are the primary bioactives. They increase BDNF expression in the hippocampus via CREB and ERK/MAPK pathways, promoting neuroplasticity, synaptogenesis, and memory formation. They enhance collagen type I synthesis through stimulation of fibroblasts and improve microcirculation via VEGF and angiopoietin modulation. Anxiolytic effects occur through positive allosteric modulation of GABA-A receptors (possibly at the benzodiazepine or neurosteroid site) and reduction of acoustic startle response (amygdala modulation). Gotu kola inhibits acetylcholinesterase (AChE), mildly increasing synaptic acetylcholine. Anti-inflammatory effects come from NF-kB inhibition (IkB stabilization) and TNF-alpha suppression. Asiatic acid may also activate PPAR-gamma.
Polygala Tenuifolia
The saponins (tenuigenin, polygalasaponins, onjisaponins) and oligosaccharide esters (3,6'-disinapoyl sucrose, tenuifolisides) have multiple neurological actions. They inhibit acetylcholinesterase (AChE) at the catalytic site, increasing synaptic acetylcholine and enhancing muscarinic M1/M4 and nicotinic receptor signaling. They promote BDNF and NGF expression via CREB and ERK/MAPK pathways, supporting neuroplasticity and neurogenesis in the hippocampus and subventricular zone. They modulate NMDA receptor function (possibly as positive allosteric modulators at the glycine site) and enhance long-term potentiation (LTP) via CaMKII and PKC. The anti-depressant effects involve monoaminergic modulation — increasing dopamine and norepinephrine via MAO inhibition or reuptake modulation — and HPA axis regulation (reducing CRH and cortisol). Tenuigenin may also activate TrkB receptors directly.
Risks & Safety
Gotu Kola
Common
Very well-tolerated. Mild GI upset, drowsiness.
Serious
Rare hepatotoxicity reported — avoid with liver disease and limit use to 6-week cycles.
Rare
Headache, dizziness, skin sensitivity to sunlight.
Polygala Tenuifolia
Common
Nausea, gastrointestinal irritation (take with food).
Serious
Limited long-term safety data in Western research.
Rare
Throat irritation, excessive salivation.
Full Profiles
Gotu Kola →
Centella asiatica is an Ayurvedic and Chinese medicine herb known as the 'herb of longevity.' It has been used for centuries to enhance memory, promote wound healing, and reduce anxiety. Modern research confirms it increases BDNF, enhances collagen synthesis, improves microcirculation, and has anxiolytic effects. Unlike most adaptogens, gotu kola has clinical evidence for improving memory and attention in healthy adults.
Polygala Tenuifolia →
Known as Yuan Zhi in Traditional Chinese Medicine, Polygala tenuifolia has been used for thousands of years as a 'will-strengthening' and memory-enhancing herb. Modern research shows it enhances BDNF expression, inhibits acetylcholinesterase, and promotes neurogenesis. Users commonly report improved verbal fluency, dream vividness, and motivation. One of the more noticeable adaptogens with acute effects.