Quick Comparison

CDP-CholinePolygala Tenuifolia
Half-Life56-71 hours (long elimination half-life)3-6 hours (tenuigenin and polygalasaponins)
Typical DosageStandard: 250-500 mg daily in 1-2 doses. Clinical (stroke/cognitive decline): 500-2000 mg daily. Most nootropic users find 250-500 mg sufficient.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.
AdministrationOral (capsules, tablets). Very well-absorbed with nearly 100% oral bioavailability.Oral (capsules, powder, tincture). Extract preferred over raw root for potency and reduced GI irritation.
Research Papers10 papers10 papers
Categories

Mechanism of Action

CDP-Choline

CDP-Choline is hydrolyzed by nucleotidases and phosphatases into choline and cytidine after oral ingestion. Choline enters the acetylcholine synthesis pathway via choline acetyltransferase. Cytidine is phosphorylated to CTP and converted to uridine monophosphate (UMP), which enters the Kennedy pathway and stimulates the synthesis of phosphatidylcholine via the enzyme CTP:phosphocholine cytidylyltransferase — phosphatidylcholine is a critical component of neuronal cell membranes and synaptic vesicles. This dual mechanism simultaneously boosts neurotransmitter production and repairs membrane damage from oxidative stress or ischemia. CDP-Choline also increases dopamine D2 receptor density in the striatum and enhances dopamine release. It may modulate glutamate excitotoxicity and support mitochondrial function.

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

CDP-Choline

Common

Headache, nausea, diarrhea, insomnia.

Serious

Very safe — extensive clinical safety data.

Rare

Blurred vision, chest pain, allergic reactions.

Polygala Tenuifolia

Common

Nausea, gastrointestinal irritation (take with food).

Serious

Limited long-term safety data in Western research.

Rare

Throat irritation, excessive salivation.

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