Alpha-GPC
A choline-containing phospholipid used as a cholinergic precursor and ergogenic aid. It has moderate human data for cognition in dementia and for power output, though a disputed observational signal links high choline intake to cardiovascular risk.
01 Overview
L-Alpha-glycerylphosphorylcholine (alpha-GPC) is a naturally occurring choline compound that raises plasma choline and acetylcholine synthesis. It has been studied in Alzheimer's disease and vascular dementia in Europe, and in sports settings for growth-hormone response and power output.
It is widely sold as a dietary supplement and is a common 'choline source' paired with racetams. A 2021 observational analysis linking supplemental alpha-GPC to elevated stroke risk has generated caution but is not established as causal.
02 Mechanism
Delivers choline across the blood-brain barrier as a precursor for acetylcholine synthesis and for membrane phosphatidylcholine.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common | 300–600 mg/day | Oral | Dementia trials used ~1200 mg/day divided. |
| Pre-workout | 600–1000 mg | Oral | Used acutely before training for power output. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Cognitive support in dementiaModerate benefit reported in European dementia trials; benefit in healthy young adults is less clear. | Clinical | ||
| Increased power outputAcute dosing improved measures of force/power in some sport studies. | Small | Clinical | |
| Choline repletionReliably raises plasma choline, supporting acetylcholine synthesis. | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Headache and cholinergic symptomsHeadache, nausea or low mood at higher doses. | Mild | Uncommon | Anecdotal | |
| Possible increased cardiovascular riskAn observational study associated supplemental alpha-GPC with higher stroke risk; causality is unproven and may relate to TMAO metabolism. | Moderate | Disputed | Disputed |