alpha-GPC Sources
α-GPC naturally occurs in the brain in limited amounts. However, choline can be obtained from several different sources, both plant and animal including soy, eggs, and red meat.
When the brain is low on free choline for acetylcholine, the brain breaks down cell membranes to cannibalize choline.
Popular supplements for choline include α-GPC, choline bitartrate and CDP-choline.
α-GPC is the most bioavailable form of choline.
One needs to take more than twice as much CDP-choline than α-GPC to get the same amount of choline.
Chemistry
Choline is a chemical precursor to produce acetylcholine.[1]
This is clinically important because there is a large body of research suggesting that learning, memory, intelligence, and mood are mediated at least in part by acetylcholine metabolism in the brain.[2]
This is commonly referred to as the "cholinergic effect".
Demonstrated Effects
Memory
A 2011 study in 26 individuals showed that daily ingestion of a nootropic blend containing α-GPC was effective in improving memory (recall, recognition, and short-term memory) at both 2 week and 10-week trial intervals.[3]
Focus
A 2010 study on 19 healthy college students showed that a nootropic blend consisting of α-GPC and other compounds (choline bitartrate, phosphatidylserine, vitamins B3, B6, and B12, folic acid, L-tyrosine, anhydrous caffeine, acetyl-L-carnitine, and naringin), resulted in increased reaction time and alertness, as measured by both a self-report questionnaire and reaction time measured by a Makoto testing device.[4]
Side Effects
There are no reported major side effects of α-GPC. Minor side effects can include heartburn and headache at doses several times the recommended amount (exceeding 2 grams per day).[5]
Safety
α-GPC is approved as a dietary supplement component under provisions of the Dietary Supplement Health and Education Act of 1994.
Published Research
- Parnetti, L., Mignini, F., Tomassoni, D., Traini, E., & Amenta, F. (2007). Cholinergic precursors in the treatment of cognitive impairment of vascular origin: ineffective approaches or need for re-evaluation?. Journal of the neurological sciences, 257(1), 264-269.
- Hasselmo, M. E. (2006). The role of acetylcholine in learning and memory. Current opinion in neurobiology, 16(6), 710-715.
- Richter, Y., Herzog, Y., Eyal, I., & Cohen, T. (2011). Cognitex supplementation in elderly adults with memory complaints: an uncontrolled open label trial. Journal of dietary supplements, 8(2), 158-168.
- Hoffman, J. R., Ratamess, N. A., Gonzalez, A., Beller, N. A., Hoffman, M. W., Olson, M., ... & Jager, R. (2010). The effects of acute and prolonged CRAM supplementation on reaction time and subjective measures of focus and alertness in healthy college students. Journal of the International Society of Sports Nutrition, 7(1), 1-8.
- Brownawell, A. M., Carmines, E. L., & Montesano, F. (2011). Safety assessment of AGPC as a food ingredient. Food and Chemical Toxicology, 49(6), 1303-1315.