Glycerophosphorylcholine
L-α-Glycerophosphorylcholine (alpha-GPC, choline alfoscerate, sn-glycero-3-phosphocholine) is a natural choline compound found in the brain. It is also a parasympathomimetic acetylcholine precursor which has been investigated for its potential for the treatment of Alzheimer's disease and other dementias.
Alpha-GPC rapidly delivers choline to the brain across the blood–brain barrier and is a biosynthetic precursor of acetylcholine. It is a non-prescription drug in most countries. The FDA determined that intake of no more than 196.2 mg/person/day is considered generally recognized as safe (GRAS).
Production
Industrially, alpha-GPC is produced by the chemical or enzymatic deacylation of phosphatidylcholine enriched soya phospholipids followed by chromatographic purification. Alpha-GPC may also be derived in small amounts from highly purified soy lecithin as well as from purified sunflower lecithin.
Safety
A retrospective cohort study involving 12 million participants in South Korea found that α-GPC users had a higher risk of stroke ( + 46 % ). The authors suggested that one possible explanation is that dysbiosis may lead to α-GPC being metabolized into trimethylamine (TMA) in the gastrointestinal tract, and then to trimethylamine N-oxide (TMAO) in the liver, which has implications for cardiovascular health. However, they also noted that the study could be influenced by confounding variables, as α-GPC is often prescribed to individuals with preexisting health risks.
A later systematic review and meta-analysis criticized the statistical analysis of the South Korean cohort study, describing it as questionable and imprecise. The review concluded that α-GPC has a favorable safety and tolerability profile and is effective in improving cognitive function and daily living in patients with dementia disorders of neurological origin, adult-onset vascular dementia, and Alzheimer’s disease.