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    Alpha-GPC (L-Alpha-Glycerylphosphorylcholine)New

    Supplement
    Nootropics
    4/10 Evidence

    A highly bioavailable choline compound used to support acetylcholine signalling, attention and memory. Evidence for cognitive benefit is concentrated in people with cerebrovascular or neurodegenerative impairment; data in healthy adults are small, and one large observational study links long-term use with higher stroke risk.

    Mechanism of Action

    Alpha-GPC crosses the blood-brain barrier and supplies choline for acetylcholine and phosphatidylcholine synthesis in neurons. It may also support membrane integrity and, at higher doses, acutely raise growth-hormone release (small exercise studies). Gut bacteria convert choline compounds to TMA/TMAO, a proposed (unproven) link to the vascular signal seen in cohort data.

    Dosing Protocol

    Recommended

    600mg per day (1,200 mg/day in clinical trials; 300-600 mg/day typical in healthy adults)

    Standard starting dose based on research

    Therapeutic Range

    300

    Minimum

    to

    1200

    Maximum

    mg per day (1,200 mg/day in clinical trials; 300-600 mg/day typical in healthy adults)

    Morning or early afternoon, divided into 1-2 doses; 300 mg about 30-60 minutes before cognitively demanding tasks

    Cycling Protocol

    No established cycling. Because of the observational stroke signal, consider the shortest effective course and reassess need every 8-12 weeks

    Dosages are general guidelines. Individual requirements vary based on body weight, health status, and specific goals. Start with lower doses and adjust based on response.

    Benefits

    Primary Benefits

    • Improved cognition, behaviour and daily function in cognitive impairment from cerebrovascular injury, mainly alongside standard care (donepezil) in small trials
    • Short-term attention and processing-speed gains at 630 mg in a small crossover trial in healthy young men

    Secondary Benefits

    Possible acute improvement in power output in resistance-trained men (small studies, inconsistent)
    Possible support for memory in healthy adults (unconfirmed)

    Safety Information

    Contraindications

    Do not use if any of the following apply:

    • •History of stroke or TIA, or high cerebrovascular risk, unless advised by a clinician
    • •Pregnancy and breastfeeding (insufficient data)
    • •Known hypersensitivity to choline compounds
    • •Uncontrolled hypertension

    Drug/Supplement Interactions

    May interact with the following. Consult a healthcare provider before combining:

    Cholinesterase inhibitors (donepezil, rivastigmine) — additive cholinergic effects; used together only under clinician supervision
    Anticholinergic drugs (oxybutynin, diphenhydramine, tricyclics) — may oppose effect
    Antihypertensives — rare reports of blood pressure changes
    Other choline sources (citicoline, choline bitartrate) — additive intake and TMAO exposure

    Potential Side Effects

    Some users may experience:

    Headache
    Heartburn and GI upset
    Insomnia or restlessness when taken late
    Dizziness
    Skin rash (uncommon)
    Fishy body odor from raised TMA in some users

    This is not a complete list of interactions or side effects. Individual responses vary. Always start with the lowest effective dose and monitor your response. Report any adverse effects to your healthcare provider.

    Quality Markers

    Look for these specific quality indicators when sourcing this compound:

    • Label states mg of alpha-GPC (not mg of blend); typical powder is 50% or 99% pure
    • Third-party tested for identity and purity
    • Avoid proprietary blends that hide the alpha-GPC dose
    • Stored sealed; the compound is hygroscopic

    Trusted Certifications

    NSF Certified
    USP Verified
    GMP Certified
    ConsumerLab Approved

    Note: Supplement quality varies dramatically between brands. Cheap supplements often contain fillers, incorrect doses, or contaminants. Investing in quality products from reputable manufacturers is essential for safety and efficacy.

    Evidence Profile

    Evidence Score

    4/10

    Emerging/Anecdotal

    Limited clinical data, primarily mechanistic studies or user reports

    Classification:
    Emerging/Moderate for clinical populations, weak for healthy adults. A 2023 Journal of Alzheimer's Disease systematic review and meta-analysis (7 RCTs plus 1 cohort) found cognitive, functional and behavioural benefit in patients with neurological conditions tied to cerebrovascular injury, but trials were small and mostly used the medicine form. A 2021 South Korean registry cohort (about 12 million adults aged 50+) associated alpha-GPC use with a 46% higher stroke risk in a dose-response pattern; this is observational and confounded by indication, but is a safety signal that has not been resolved by a randomized trial. A 2024 crossover trial in 20 healthy young men (630 mg) improved Stroop scores; seen only via a secondary summary. Scored Emerging (4). Evidence

    Evidence Scale

    8-10

    Strong

    5-7

    Moderate

    1-4

    Emerging

    PHS
    671
    / 1000
    T3
    Longevity Operator

    Sample member

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