Skip to content
superstack
Draft entry. Written from the cited papers but not yet reviewed by a person. Check the references before relying on any claim.
Choline source· Cholinergic

Alpha-GPC

also Choline alfoscerate · L-alpha-Glycerylphosphorylcholine · Glycerophosphocholine · GPC

Alpha-GPC (choline alfoscerate) is a choline-containing phospholipid breakdown product, sold as a prescription drug in some countries and a supplement elsewhere [1]. It is a precursor of both choline and acetylcholine [1]. Its record is unusually mixed. One very large Korean cohort linked it to lower dementia conversion [2], while another linked it to higher 10-year stroke risk [3].

An effective choline donor with a real open question about long-term stroke risk; it is worth knowing about that signal before taking it daily for years.

2D chemical structure of Alpha-GPC
C8H20NO6P257.22 g/molCID 657272 ↗
Human observational7 papers · 1991–2025 · 7 journals · 6 in humans
  • meta-analysis
  • RCT
  • trial
  • observational
  • preclinical / case
  • review / patent / other
  • retracted
1991 · clinical trial · A multicentre trial to evaluate the efficacy and tolerability of alpha-glycerylphosphorylcholine versus cytosine diphosphocholine in patients with vascular dementia.2003 · RCT · Cognitive improvement in mild to moderate Alzheimer's dementia after treatment with the acetylcholine precursor choline alfoscerate: a multicenter, double-blind, randomized, placebo-controlled trial.2015 · RCT · The effect of 6 days of alpha glycerylphosphorylcholine on isometric strength.2021 · observational · Association of L-α Glycerylphosphorylcholine With Subsequent Stroke Risk After 10 Years.2024 · RCT · Acute Alpha-Glycerylphosphorylcholine Supplementation Enhances Cognitive Performance in Healthy Men.2025 · review · Unlocking the Potential of l-α-Glycerylphosphorylcholine: From Metabolic Pathways to Therapeutic Applications.2025 · observational · Association between L-α glycerylphosphorylcholine use and delayed dementia conversion: A nationwide longitudinal study in South Korea.
in its favor
  • + Efficient choline and acetylcholine precursor
  • + Outperformed citicoline in an old vascular dementia trial
  • + Linked to slower dementia conversion in a large cohort
watch for
  • − Linked to higher 10-year stroke risk in a 12-million-person cohort
  • − Much of the evidence is observational

Overview

Alpha-GPC is used as a cognitive supplement and, in some countries, as a prescription drug for cognitive decline. A 2025 review summarizes preclinical and clinical evidence for cognitive impairment in Alzheimer's disease, vascular dementia and cerebral ischemia. It also covers claimed benefits for exercise performance and growth hormone release [1].

The oldest comparison with Citicoline is a 1991 open, multicenter trial in 120 patients with vascular dementia. Both drugs were given intramuscularly. Both improved symptoms, and alpha-GPC scored higher on most tests [4].

Mechanism

Alpha-GPC is metabolized to choline and glycerophosphate. That makes it a precursor of acetylcholine and of membrane phospholipids [1]. Preclinical work also reports GABA release, protein kinase C activation, hippocampal neurogenesis and anti-inflammatory effects [1].

Direct targetswhat the molecule itself binds or acts on
  • Acetylcholine synthesisactivates
    supplies choline for acetylcholine and phospholipid synthesis [1]
    moderate

Dosing

as studied or commonly reported; not a recommendation

Doses below are what studies used or, where marked, what is commonly reported. None is a recommendation.

Oral

  • 400 mg
    mild to moderate Alzheimer's dementia
    3 times a day · 180 days
    human study[5]
  • 600 mg
    isometric strength in healthy adults
    daily · 6 days
    human study[6]
  • 315 or 630 mg
    cognition in resistance-trained men
    single dose, tested 60 minutes later
    human study[7]
  • 300–600 mg
    focus or training
    once a day, before training or study
    commonly reported, not from trials

Intramuscular injection

  • 1 g
    vascular dementia (open trial against citicoline)
    daily · 90 days
    human study[4]
Notes
In a Korean cohort, stroke risk over 10 years rose with the amount of alpha-GPC prescribed [3]. That is an association, not proof, but it is the main reason to be cautious about long, high-dose use.

Safety

risks and cautions, not medical advice

The safety question is a single, very large observational signal. In a Korean national cohort of about 12 million people aged 50 or over, alpha-GPC users had a 43% higher adjusted risk of stroke over 10 years than matched non-users, with a dose-response relationship [3].

Observational data cannot prove cause, and people who are prescribed alpha-GPC may already differ in vascular risk in ways the adjustment did not capture. A later cohort of people with mild cognitive impairment found lower dementia conversion, and lower stroke risk among those who did not progress [2]. The two studies point in different directions, and neither is a randomized trial.

Adverse effects
reported, not universal
  • Associated with higher long-term stroke risk in one large cohort; causation unproven [3]
Cautions
who should think twice
  • People with cardiovascular risk factors may want to weigh the stroke signal before long-term daily use [3]
Limits of the evidence
what has not been shown
  • The key safety and benefit data are observational and cannot establish cause [2][3]
  • The head-to-head trial with citicoline was open-label, not blinded [4]

Interactions

documented pairs only, not exhaustive
  • Citicoline
    compatible
    No adverse interaction documented; both supply choline, so combining them mainly duplicates one mechanism
  • any racetam
    compatible
    Commonly combined in practice; no adverse interaction documented

FAQ

Does alpha-GPC cause strokes?
One 12-million-person cohort found a dose-dependent association with higher 10-year stroke risk [3]. Association is not causation, and another cohort in people with mild cognitive impairment found lower stroke risk [2].

References

entry last reviewed 2026-09-18
  1. [1]
  2. [2]
    Association between L-α glycerylphosphorylcholine use and delayed dementia conversion: A nationwide longitudinal study in South Korea.
    Kim HK, Park S, Kim SW et al.J Prev Alzheimers Dis 2025observational · humanPMID 40155153◌ unreviewed
  3. [3]
    Association of L-α Glycerylphosphorylcholine With Subsequent Stroke Risk After 10 Years.
    Lee G, Choi S, Chang J et al.JAMA Netw Open 2021observational · humanPMID 34817582◌ unreviewed
  4. [4]
  5. [5]
  6. [6]
    The effect of 6 days of alpha glycerylphosphorylcholine on isometric strength.
    Bellar D, LeBlanc NR, Campbell BJ Int Soc Sports Nutr 2015RCT · humanPMID 26582972◌ unreviewed
  7. [7]