Alpha GPC (L-Alpha Glycerylphosphorylcholine) is a very effective choline source. Alpha GPC is a cholinergic supplement that increases the availability of the nutrient choline in the brain. This leads to increased synthesis of the neurotransmitter acetylcholine which is implicated in memory, focus, reasoning and learning.
Synonyms：Alpha GPC (Alpha L-Glycerylphosphorylcholine, Choline Alfoscerate)
Formal Name：[(2S)-2,3-Dihydroxypropyl] 2-trimethylazaniumylethyl phosphate
Molecular Weight: 257.221 g/mol
CAS Number: 28319-77-9
A-GPC, Alpha-glycerophosphocholine, choline alphoscerate, GPC.
Alpha GPC is a naturally occurring choline intermediary that is formed when the body breaks down cell membranes for choline. As a supplement Alpha GPC is a highly bio available form of choline that crosses the blood brain barrier and raises brain levels of choline. Inside the brain choline supports cell membrane and neurotransmitter synthesis. Of all the supplemental forms of choline, GPC is probably the most cholinergic per gram, as it’s 40% choline by weight and appears to be well absorbed.
Increased Cognitive Functioning
Greater Mental Focus
Higher Attention Span
Increased Sensory Perception
The molecular structure of Alpha GPC features a choline molecule bound by a phosphate group to a glycerol molecule. It has also been described as a phosphatidylcholine lecithin molecule with two of the fatty acids missing. This makes it both a phospholipid and a source of 40% free choline by weight. A typical 1,200 mg per day dosage of Alpha GPC therefore yields 480 mg of choline.
It is most commonly compared to Citicoline (CDP Choline) which is another nootropic bio-available source of choline for the brain. Citicoline provides 21% choline by weight which means that the effective dosage for this supplement is almost twice that of Alpha GPC. Ingesting the same dosages of both of these compounds results in a greater serum increase of choline for those individuals given Alpha GPC. In clinical interventions, Alpha GPC is shown to be more effective and more potent than both choline and CDP Choline.
The primary mechanism of action for Alpha GPC is an increase in cholinergic neurotransmission. 150 mg/kg/day administered to rats significantly increased acetylcholine neurotransmitter concentrations in the frontal cortex, but not the striatum or cerebellum. Alpha GPC also stimulated increased vesicular acetylcholine transporter (VAChT) expression and choline transporter (CHT) expression in all brain areas examined. These presynaptic cholinergic transporters are responsible for sustaining ACh synthesis and release from neurons.
Dopamine and Serotonin
Alpha GPC is observed to increase dopamine and serotonin concentrations in the cerebellum and frontal cortex of rats following administration of a 150mg/kg oral dosage. This increase is not reported when administering an equal dosage of choline from Citicoline (CDP Choline). Alpha GPC also increases expression of the dopamine transporter but not the serotonin transporter.  In another study, Alpha GPC was observed to increase potassium (K+) stimulated dopamine release in the brain.
GPC appears to be a remarkably safe nootropic that processes few-little side effects in the therapeutic dose range. One trial reported side effects in 2.4% of all patients, which consisted by mainly of nausea (0.5%), heartburn (0.7%) and insomnia (0.4%) at a dose of 1200mg/day. The LD50 for GPC is 10,000mg / Kilo for rodents when administered orally. A drop in food consumption and increase in bodyweight was noted in rodents at a dose of 1000mg/kg.