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Alpha-GPC Side Effects & Safety

Evidence:Moderate
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This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Safety Profile

Overall safety rating: Generally Safe

Potential Side Effects

  • Headache (often from excess acetylcholine — reduce dose)
  • Digestive upset, nausea, or diarrhea at higher doses
  • Fishy body odor from choline metabolism (trimethylamine)
  • Rare: dizziness or insomnia
  • Potential concern: large observational study (2021) linked chronic high-dose choline supplements to increased stroke risk — further research needed

Drug & Supplement Interactions

  • Anticholinergic medications — Alpha-GPC may counteract their therapeutic effects
  • Cholinesterase inhibitors (donepezil, rivastigmine) — additive cholinergic effects, risk of cholinergic crisis
  • Scopolamine — Alpha-GPC may reduce its efficacy

Maximum Dose

Do not exceed: 1200mg/day (prescription doses in Europe)

Full Alpha-GPC Guide

References

  1. RCTDe Jesus Moreno M (2003). Cognitive improvement in mild to moderate Alzheimer's dementia after treatment with the cholinergic precursor choline alfoscerate. Clinical Therapeutics. DOI PubMed
  2. RCTZiegenfuss T, Landis J, Hofheins J (2008). Acute supplementation with alpha-glycerylphosphorylcholine augments growth hormone response to, and peak force production during, resistance exercise. Journal of the International Society of Sports Nutrition. DOI
  3. RCTKawamura T, Okubo T, Sato K, et al. (2012). Glycerophosphocholine enhances growth hormone secretion and fat oxidation in young adults. Nutrition. DOI PubMed
  4. RCTYamashita S, Kawada N, Wang W, Susaki K, et al. (2023). Effects of egg yolk choline intake on cognitive functions and plasma choline levels in healthy middle-aged and older Japanese: a randomized double-blinded placebo-controlled parallel-group study.. Lipids in health and disease. DOI PubMed