Alpha-GPC
Also known as: L-Alpha Glycerylphosphorylcholine, Choline Alfoscerate, α-GPC
Highly bioavailable choline donor that elevates brain acetylcholine levels, supporting memory, learning, and muscular power output via enhanced neuromuscular junction signaling.
Last reviewed: 2024-07-01 · 2 indexed studies
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Overview
Alpha-GPC is the most bioavailable choline source, rapidly crossing the blood-brain barrier to serve as a precursor for acetylcholine synthesis. It supports both cognitive function and physical performance by enhancing neuromuscular signaling.
Mechanism & Function
Alpha-GPC · C₈H₂₀NO₆P — source: PubChem CID 657272
Alpha-GPC crosses the blood-brain barrier and releases free choline, which combines with acetyl-CoA via ChAT to form acetylcholine for memory and focus.
Highly hygroscopic off-white powder — usually encapsulated to stay dry.
- Capsule
- Powder
- Liquid Cap
Capsule is generally preferred for bioavailability or efficacy.
Mechanism of Action
Rapidly absorbed and converted to phosphatidylcholine in the brain. Donates choline for acetylcholine (ACh) synthesis, the primary neurotransmitter for memory encoding and motor neuron activation. Also supports neuronal membrane integrity through phospholipid turnover.
Physiological Role
Primary dietary precursor for acetylcholine. Supports cholinergic neurotransmission essential for learning, memory consolidation, attention, and voluntary muscle contraction.
Primary Pathways
Performance / Health Relevance
Enhances power output and rate of force development in resistance training. Supports cognitive function under fatigue and stress. May augment acute growth hormone response to exercise.
Evidence Review
No meta-analyses or systematic reviews indexed for this ingredient yet.
Dimensions marked N/A have no indexed evidence of that class. They are shown as unavailable rather than scored.
Compare Choline Forms
Full comparison4 choline forms are indexed. Bioavailability, clinical evidence, and best-use cases differ meaningfully between them.
| Form | Evidence |
|---|---|
Alpha-GPCThis page Superior choline bioavailability vs CDP-choline or choline bitartrate | 78/100 |
| Silicon (Orthosilicic Acid) Oral orthosilicic acid formulations showed measurable increases in plasma and urinary Si over 6 h, indicating absorption; stabilised forms (choline or vanillin complexes) aim to limit polymerisation and improve bioavailability. | 61/100 |
| Choline (Choline Bitartrate) Choline bitartrate is well-absorbed, but significant first-pass metabolism can limit its systemic bioavailability for direct cholinergic effects compared to more advanced forms like CDP-choline or Alpha-GPC. | 60/100 |
| Citicoline Near-complete oral absorption; hydrolysed to choline and cytidine before crossing the blood-brain barrier. | 45/100 |
Practical Use & Dosage
- Minimum Effective Dose
- 300mg/day
- Optimal Range
- 300–600mg/day
- Upper / Caution Level
- 1200mg/day
- Timing
- 30–60 min pre-workout or morning for cognition
- Best Format
- Capsule or powder (hygroscopic)
- Bioavailability
- Superior choline bioavailability vs CDP-choline or choline bitartrate
- Absorption Considerations
- Fat-soluble; absorb better with a small meal containing dietary fat
Safety & Interactions
Side Effects
- •Headache (excess ACh)
- •GI upset at high doses
- •Fishy body odor (rare)
Contraindications
- Bipolar disorder (cholinergic sensitivity)
Drug Interactions
- •Acetylcholinesterase inhibitors (additive)
- •Scopolamine (opposing)
Who Should Avoid
- •Those on anticholinergic medications without medical guidance
Monitoring
Monitor for headache or overstimulation at higher doses
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Alpha-GPC typically used or indicated?
Alpha-GPC is most commonly used for: Cognitive enhancement, Memory support, Power output, Acetylcholine precursor. Primary dietary precursor for acetylcholine. Supports cholinergic neurotransmission essential for learning, memory consolidation, attention, and voluntary muscle contraction.
How does Alpha-GPC work?
Rapidly absorbed and converted to phosphatidylcholine in the brain. Donates choline for acetylcholine (ACh) synthesis, the primary neurotransmitter for memory encoding and motor neuron activation. Also supports neuronal membrane integrity through phospholipid turnover.
What is the recommended dose of Alpha-GPC?
The optimal range is 300–600mg/day. with a minimum effective dose of 300mg/day. Best taken: 30–60 min pre-workout or morning for cognition. Upper / caution level: 1200mg/day.
What are the side effects of Alpha-GPC?
Reported side effects include: Headache (excess ACh); GI upset at high doses; and Fishy body odor (rare). Monitoring: Monitor for headache or overstimulation at higher doses
Does Alpha-GPC interact with medications?
Known or theoretical interactions: Acetylcholinesterase inhibitors (additive); and Scopolamine (opposing). Always check with a clinician before combining with prescription medication.
Who should avoid Alpha-GPC?
Alpha-GPC is generally not recommended for: Those on anticholinergic medications without medical guidance; and Bipolar disorder (cholinergic sensitivity).
How strong is the evidence for Alpha-GPC?
Evidence level: Strong (overall score 78/100), based on 2 indexed studies on SuppIndex.
Research & References (2)
Acute supplementation with alpha-glycerylphosphorylcholine augments growth hormone response to exercise
600mg Alpha-GPC increased peak GH response by 44-fold compared to placebo during resistance exercise.
The effect of alpha-glycerylphosphorylcholine on isometric force production
600mg Alpha-GPC significantly increased isometric mid-thigh pull force vs placebo in resistance-trained men.
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Research Overview
Strong EvidenceCite this ingredient
One-click citation export in APA, MLA, Chicago, BibTeX, or HTML. The URL below is stable and safe to link.
Stable URL
https://thesuppindex.com/ingredients/alpha-gpc
SuppIndex. (2026). Alpha-GPC: Evidence summary, dosage and clinical studies. Retrieved October 23, 2026, from https://thesuppindex.com/ingredients/alpha-gpc
Based on 2 indexed studies · Evidence level: Strong.
Goal Ratings
Stack Compatibility
Excellent synergy with racetams and caffeine. Pairs well with creatine for cognitive stacking.
Products (2)
Gorilla Mind
Gorilla Mind Rush
Nootropics Depot
Alpha-GPC 300mg