Alpha-GPC (L-Alpha Glycerylphosphorylcholine) — Brain
Bioavailable choline source that crosses the blood-brain barrier. Used for cognitive support and as adjunct to racetam nootropics.
Overview
Alpha-GPC (L-alpha-glycerylphosphorylcholine, choline alfoscerate) is a natural choline compound found in the brain and a highly bioavailable source of choline that efficiently crosses the blood-brain barrier. It is the most effective choline supplement for increasing brain acetylcholine levels. Alpha-GPC is approved as a prescription drug in Europe (brand names Gliatilin, Delecit) for treatment of cognitive decline, Alzheimer's disease, and post-stroke cognitive recovery. In the United States, it is classified as a dietary supplement. A systematic review of 13 clinical trials found that alpha-GPC improved cognitive function in patients with Alzheimer's disease and vascular dementia, with effects comparable to or greater than other cholinergic therapies. Alpha-GPC provides choline for two critical pathways: acetylcholine synthesis (neurotransmitter) and phosphatidylcholine synthesis (membrane structural component). In the nootropic community, alpha-GPC is commonly used as a foundational supplement and as a complement to racetam nootropics, which increase acetylcholine turnover and may deplete choline stores. Alpha-GPC has also gained attention in sports performance, with studies suggesting that 600 mg acutely increases growth hormone secretion and improves power output, though results are mixed.
Indications
- Approved (Europe): Cognitive decline, Alzheimer's disease, post-stroke recovery
- Dietary supplement (US): Cognitive support and choline supplementation
- Off-label: Adjunct to racetam nootropics (choline depletion prevention)
- Off-label: Sports performance and growth hormone secretion
Mechanism of Action
Alpha-GPC crosses the blood-brain barrier more efficiently than other choline sources due to its phospholipid structure
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Alpha-GPC | 300 mg | Once or twice daily | Standard supplemental dose for cognitive support |
| Alpha-GPC | 600 mg | Twice daily (1,200 mg/day) | European clinical dose for cognitive decline |
| Alpha-GPC | 600 mg | 30-60 min pre-workout | Sports performance / GH release dose |
Evidence Grade
GRADE B
Safety & Contraindications
- Generally well-tolerated at standard doses
- GI upset: heartburn, nausea, diarrhea at high doses
- Headache (less common than with other choline sources)
- Fishy body odor possible at very high doses (trimethylamine metabolism)
- A 2021 observational study raised concerns about increased stroke risk with long-term use — causality not established
- Hygroscopic powder — absorbs moisture readily