Alpha GPC is a potent form of the nutrient choline which naturally occurs in the brain, and it is the building block to acetylcholine; a chemical which is released when conducting cognitive tasks such as memory retention or learning.
Why the interest in choline?
Almost a decade ago the box office hit “limitless” sparked an interest amongst millions of people into cognitive enhancers . Cognitive enhancers are utilised for an array of personal and professional reasons; users predominantly share the same goal: to be smarter, be more productive, and to be the best version of themselves.
Workers in Silicon Valley were the early adopters of cognitive enhancers . These tech workers used ADHD drugs such as Adderall or Ritalin to optimise their fast-working performance instead of using it for medicinal purposes . The UK also seen a similar increase, with the University of Oxford (2015) reporting that 1 in 5 of its students consumes pills such as Modafinil, a drug used for narcolepsy, to help improve their concentration and to obtain a sense of wakefulness .
Some of these drugs are obtained by prescription and repurposed. The Journal of Public Health suggests a significant proportion are obtained online which raises safety concerns . Nutritional options may offer a safer alternative and nutrients such as choline may modulate attention-holding capacity and memory processing .
Benefits of choline
Choline is a precursor to a chemical messenger called acetylcholine, which is responsible for memory retention and learning . One study showed from visual performance tests that reaction time and accuracy was improved from increasing choline intake. Increase choline intake was also associated with increased acetylcholine levels and more efficient neural processing . US adults males require 550mg choline and adult females require 425mg of choline.
The liver produces a small amount of choline that is insufficient to meet your needs so healthcare professionals recommend that you obtain additional choline through diet intake or supplementation . The highest foods rich in choline can be found in animal proteins such as beef kidney (513mg per 100mg) however alternative plant sources such as soy flour can still offer 192 mg per 100g .
Dietary choline does have a challenge in increasing acetylcholine in the brain compared to some forms of choline. Food derived choline requires special transporters to carry free-form choline across the blood-brain barrier  and it is believed that this only takes place when the concentrations of choline in the brain are lower than blood serum levels.
How does Alpha GPC work?
Alpha GlycerylPhosphorylCholine naturally resides in the brain and plays an important role in producing acetylcholine . When absorbed into the bloodstream, Alpha GPC freely crosses the blood-brain barrier to deliver free forms of choline, which are then converted to acetylcholine . Alpha GPC has shown to spike acetylcholine levels after 1 - 3 hours post-ingestion .
Administration of Alpha GPC for 20 days in animal studies showed an improvement in learning, and memory capacity  whilst human studies on mild cognitive impairment showed that 71% of 2,044 patients that consumed a daily dose of alpha GPC corresponded to “no cognitive decline” or “forgetfulness” .
Which choline source is the best?
The European Food Safety Authority recognises two certified health claims for choline. Choline contributes to normal lipid metabolism and the maintenance of normal liver function .
Table 1: Comparison between the different forms of choline and their ability to cross the blood-brain barrier.
|Source||Freely enters the blood-brain barrier||Amount of choline by weight (%)||Recommended dose (mg)||Cost||Main functional benefit|
|Alpha GPC 99%||fermented from soy lecithin.||✓||40||
500 – 1200
|Premium||Acetylcholine in the brain|
|Alpha GPC 50%||fermented from soy lecithin.||✓||20||1000-2400||Premium||Acetylcholine in the brain|
|Citicoline (CDP)||synthetic||✓||18.5||500 - 2000 ||Premium||Phosphatidylcholine precursor|
|Choline bitartrate||synthetic||X||41||2000mg *Tolerable limit. Limited evidence on brain functions ||Inexpensive||Liver function|
if you are looking for an inexpensive form of choline for liver function you may want to consider choline bitartrate. If you’re looking for forms of choline that can freely cross the blood-brain barrier - Alpha GPC 99%, Alpha GPC 50% or CPD would be more favourable options.
 Zwart, H. (2013) Limitless as a Neuro-Pharmaceutical Experiment and as a Daseinsanalyse: On the Use of Fiction in Preparatory Debates on Cognitive Enhancement. Social Science Research Network.  Amirtha, T. (2016). Scientists and Silicon Valley want to prove psychoactive drugs are healthy.  Washington post (2017) Tweaking brains with ‘smart drugs’ to get ahead in Silicon Valley.  The Oxford Student (2015) Almost one in five oxford sudents use study drugs, survey reveals.  Kazemi, D.M., Borsari, B., Levine, M.J., Dooley, B. (2017). Systematic review of surveillance by social media platforms for illicit drug use. Journal of Public Health.  Healthline (2018) Choline? An Essential Nutrient With Many Benefits.  The University of Granada (2013) Vitamin B: Choline Intake Improves Memory and Attention-Holding Capacity.  Ziesel et al. (1991) Choline, an essential nutrient for humans. The FASEB journal.
 Hasselmo, M.E. (2006). The role of acetylcholine in learning and memory. Current opinion on Neurobiology Edwards et al. (2019) Dietary choline is related to neural efficiency during a selective attention task among middle-aged adults with overweight and obesity. Nutritional Neuroscience.  National Institute of Health (2020) Choline.  Nutrition Data (2018) Foods highest in choline.  European Food Safety Authority (2016) Dietary Reference Values for Choline.  Examine.com (2018) Alpha-GPC Research Analysis.  Bekdash (2019) Neuroprotective Effects of Choline and Other Methyl Donors. Nutrients.  Schettini et al. (1992). Molecular mechanisms mediating the effects of l-α-glycerylphosphorylcholine, a new cogni-tion-enhancing drug, on behavioral and biochemical parameters in young and aged rats. Pharmacol-ogy Biochemistry and Behavior.  Drago et al. (1992) Behavioral effects of L-α-glycerylphosphorylcholine: Influence on cognitive mechanisms in the rat. Pharmacology Biochemistry and Behavior.  Sangiorgi et al. (1994) α-Glycerophosphocholine in the Mental Recovery of Cerebral Ischemic Attacks. Annals of the New York Academy of Sciences.  European Food Safety Authority (2020) Nutrition and Health Claims.  Moreno (2003) Cognitive improvement in mild to moderate Alzheimer’s dementia after treatment with the acetylcholine precursor choline alfoscerate: A multicenter, double-blind, random-ized, placebo-controlled trial. Clinical Therapeutics. Clark et al. (1999) A Randomized Efficacy Trial of Citicoline in Patients With Acute Ischemic Stroke. Stroke.  Tabassum et al. (2017) chronic choline supplementation improves cognitive and motor performance via modulating oxidative and neurochemical in rats. Pharmacology, Biochemistry Behaviour.